PHASE 3 SUBWATERSHED MANAGEMENT STRATEGY AND IMPLEMENTATION

Transcription

1 PHASE 3 SUBWATERSHED MANAGEMENT STRATEGY AND IMPLEMENTATION 1. INTRODUCTION 1.1 Background The North West Brampton Subwatershed Study (SWS) process for the Huttonville Creek and Fletcher s Creek has been broken down into four separate but linked phases. Figure 1 outlines the relationship between the North West Brampton Subwatershed Study and the Credit River Water Management Strategy (CRWMS) and the key questions that were to be answered at the end of each phase. The Subwatershed Study has been conducted to assist in the establishment of a land use and associated management system for the Mount Pleasant Community Secondary Planning Area. In addition, the Subwatershed Study was complemented by a higher level Landscape Scale Analysis offering a broader perspective on resource linkages outside of the stormwater standards. North West Brampton Landscape Scale Analysis The Draft North West Brampton Landscape Scale Analysis (LSA) was issued in August The LSA is a parallel regional study intended to provide an overview summary of landscape level functions within a study area extending 2.5 km beyond the Fletcher s Creek and Huttonville Creek subwatershed limits. The purpose of the LSA is to support the planning for the natural heritage system in North West Brampton by placing the study area within in a broad environmental system context. The 2007 draft LSA report contained the detailed GIS methodology which was developed under the guidance of a Technical Steering Committee (TSC) with representation from the City of Brampton, Credit Valley Conservation, Toronto and Region Conservation Authority, Ministry of Natural Resources, NWBLG, and Dougan & Associates. The key GIS map products summarized the regional context of the Mount Pleasant lands, analyzed and summarized natural area cover, hydrologic functions, and preliminary restoration opportunities to improve hydrologic functions, identified natural areas according to their total functional priority, summarized stream ratings and barriers, and identified existing as well as potential corridors and linkages at the LSA scale. GIS summaries are included of original and current natural and urban cover, as well as recent change in cover ( , ). The draft LSA report concluded with preliminary Principles and Strategies to guide natural heritage planning in the North West Brampton subwatersheds. These were considered in Phase 2 along with other guiding documents. The Draft LSA Report has been updated based on comments received in the fall of 2007, and is being circulated at the same time as this Draft Final Subwatershed Study for the Huttonville and Fletcher s Creeks. Due to the period of time that has elapsed since the release of the Draft LSA Report in August 2007, the updated draft contains text edits and refined graphics based on TSC comments; additional changes will be finalized once the TSC is re-assembled. The LSA is intended to be finalized once Phase 3 of the Subwatershed Study is completed, to reflect the changes that will occur through the Project Number:

2 implementation of the Mount Pleasant Secondary Plan, as well as other initiatives in progress, such as the Mayfield West CEIS. Phase 1: Subwatershed Characterization Report Phase 1 Characterization, submitted December 2007 characterized the resources associated with each Subwatershed by study discipline (i.e. hydrology/hydraulics, hydrogeology, water quality, stream morphology, aquatic and terrestrial ecology) to establish a baseline inventory for use in subsequent study phases. In order to better understand the fundamental elements of the respective subwatersheds, in terms of their environmental features, attributes and associated functions, it was necessary to integrate the respective disciplines and associated assessments, into a cohesive framework. Subsequently, the field work and accompanying assessments, associated with subwatershed characterization, was used to establish various principles, unique to the overall study area. The principles reflected certain properties and characteristics of the respective subwatersheds, which depending on their nature have led to certain implications for (to) management associated with future land use changes. Lastly, the Characterization Phase ranked each of the watercourse reaches and terrestrial spatial units through integration with each discipline. Phase 2: Point of Departure (POD) Land Use Subwatershed Impact Analysis During 2008 and early 2009 extensive discussions took place between stakeholders on the land use and natural heritage system planning being considered for the Mount Pleasant Community. In addition, dialogue was initiated on Subwatershed Targets ultimately leading to a set of working targets for consideration. In early 2009, a land use plan, termed the Point of Departure Plan was prepared by City staff for formal impact testing. The purpose of the testing was to determine if the various subwatershed targets could be met with respect to overall environmental goals and objectives. The series of working targets evolved from a watershed scale to a subwatershed scale through a consultative process involving the City, Credit Valley Conservation, Peel Region, Ministry of Natural Resources, Area Landowners, and other stakeholders. Based on the POD impact assessment results, input was formulated for the subsequent land use plan termed the Second Generation Plan (2G) in the way of land use changes and modified management directives. Phase 2: Second Generation (2G) Land Use Subwatershed Impact Analysis The preparation of the 2G Plan was a collaborative effort between the Subwatershed Study Team, CVC, MNR, Department of Fisheries and Oceans (DFO) and the MPLG. The 2G Plan reflected consultation that refined the key elements of the POD Plan to develop a functional Natural Heritage System that placed a strong emphasis on the protection of key existing natural features and the creation and/or maintenance of key natural functions and linkages, along with the application of feature specific buffers. As a requirement of the Mount Pleasant Community Secondary Plan Land Use Plan (2G) going forward to Council, the, CVC, MNR and MPLG prepared and agreed upon the Implementation Principles for the Mount Pleasant Subwatershed Study, November 24, 2009 Project Number:

3 (Principles document, ref. Phase 2 Appendix H ) which defines the elements of the proposed natural heritage system plan, as well as the implementation approach. Schedules A, B and C are to be read in conjunction with the Principles wherein: Schedule A is the proposed Secondary Plan Natural Heritage System (SPNHS) (November 24, 2009) which summarizes the proposed NHS graphically, with natural feature annotations; Schedule B consists of vignettes prepared to illustrate the intent of corridor restoration and enhancement of the NHS in key areas of the East Huttonville Creek system; and Schedule C is the Mount Pleasant Secondary Plan Work Plan and Schedule. The agreed upon elements of this Plan were tested through the 2G Plan impact assessment. Based on the results of the 2G Plan assessment, no significant land use changes were determined (i.e. additional Fletcher s Creek stream corridor and modified stream corridor widths), although further refinement of the management systems was required to improve upon certain discipline results in comparison to the working targets. Phase 3: Management Strategies and Implementation Plan Phase 3 has been based on the 3G Impact Analysis as part of Phase 2, and has further refined the management system required for the 3G Land Use Plan. Phase 3 has established a set of management solutions that represent input into the Secondary Plan process including Block Planning, to achieve the identified subwatershed goals and objectives, in addition to the recommendations of the other integral component studies being undertaken for the Mount Pleasant Secondary Plan. The Implementation Plan has been prepared to ensure compliance by identifying specific actions in the following areas: Planning (i.e. land use designations and form) and Policy, Rehabilitation and Retrofit, Stewardship, Monitoring, and Research and Development. Phase 4: Long-Term Monitoring Plan Phase 4 involves the long-term monitoring initiative that evaluates the effectiveness of the finalized management strategies by assessing whether the assumptions are appropriate and predictions are correct, and determining if parts of the plan and the management strategies should be modified. Phase 4 will not be conducted as part of this study, however, further details will be offered by the development proponents, in consultation with the and Credit Valley Conservation. 1.2 Purpose of Phase 3 As described in Section 1.1 the purpose of Phase 3 is to establish the management measures and practices for the Mount Pleasant Community based on the 3G Land Use Plan (refined 2G) as evaluated within the Land Use Impact Assessment conducted as part of Phase 2. The performance assessment has been based on the various management solutions with respect to Mount Pleasant Secondary Plan policies, and Mount Pleasant Subwatershed Study Targets (Table 2.1), Memorandum of Understanding and applicable legislation (ref. Phase 2, Project Number:

4 Appendix H ). The management solutions are to provide direction and input into the Block Plan and EIR Stage being prepared in parallel to Phase 3. In addition, the monitoring strategy is to establish requirements from each discipline to evaluate how the respective management solutions are functioning as related to the Subwatershed goals, objectives and targets. Project Number:

5 Figure 1 Process Relationship to the Credit River Water Management Strategy Credit River Water Management Strategy identifies: Sources of contamination Key issues Goals Preliminary mitigative measures Water Resource targets Resource constraints LSA Phase 1 Subwatershed Characterization and Integration Phase 2 Impact Analysis Phase 3 Management Strategy and Implementation Phase 4 Long-term Monitoring Plan What information do we already have? What are the information gaps? What are the resources? What are the functions & linkages between environmental resources? What are the needs of City initiatives (i.e. transportation studies, etc.? What are the goals for the subwatershed? What are the stressors? How will impacts be evaluated? What are the impacts from the stressors? What is the status of City initiatives? What are pros and cons of all solutions What is the preferred solution & the criteria for selection? Who will be responsible for addressing the recommendations? What is the status of City initiatives? Have goals been met? Are the original assumptions appropriate? Should parts of the plan be modified when more information is available? What is the status of City initiatives (i.e. transportation studies, etc.)? How do you integrate science, management and public needs? Project Number:

6 2. MANAGEMENT STRATEGIES 2.1 Introduction The purpose of the Management Strategy is to provide a set of recommendations to achieve the Landscape-Scale, Subwatershed-Scale and Local Scale Goals and Objectives, as related to currently approved Policies and Legislation. The subwatershed goals and objectives are based upon the planned community, which has been developed using the Planning Framework. The following outlines the Planning Framework for the Mount Pleasant Community, extracted from the Planning, Design & Development Committee, Status Report, June 5, 2007: Community Vision Statement Mount Pleasant Community Vision Statement, Planning Objectives & Planning Framework Mount Pleasant will be planned as a signature transit oriented community in North West Brampton that will be comprehensively designed around the principles of environmental sustainability. Planning Objectives The planning objectives related to the Subwatershed Study disciplines include the following: 1. Plan for a well designed, mixed-use pedestrian friendly community that is of the highest quality built form for both public and private uses that provides a variety of housing forms and densities, employment opportunities and promotes public safety. 2. Identify a natural heritage system that balances the protection, preservation and enhancement of natural features and functions with the development principles of the Growth Plan to achieve a compact and complete community that takes into account the limited financial resources of the City. 3. Include appropriate, cost effective and innovative planning and development standards to guide the development of the Mount Pleasant Community including, flexible zoning standards, on street parking, reduced road right-of-way widths and laneways. 4. Identify a public open space system that is designed for a highly urban context that contains both active and passive facilities that are oriented towards the Transit Spine and linear pedestrian connections and where local serving facilities are within an easy walk of neighbourhood precincts. 5. Incorporate policies that encourage practical and cost effective innovations to support the development of a sustainable community that encourages the application of low impact development in appropriate locations, promotes green building designs, sets Project Number:

7 targets for an urban forest canopy and provides incentives for enhancing natural features. As a result of the planning framework, and as part of the overall process of establishing subwatershed scale goals, objectives, and targets, there has been a recognition/understanding of the context of the governing legislation with respect to resource management. As such, various acts, guidelines, and policies which exist at a federal, provincial and municipal (upper and lower tier) level have been used to provide a framework for identifying, assessing, conserving and ultimately managing the impacts associated with land use change proposed for this area. The Characterization report lists the pertinent acts, guidelines and policies relevant to this subwatershed study in developing the working targets listed in Table The 2007 Credit River Water Management Strategy (CRWMS) provides high-level guidance to local municipalities on a broad range of environmental matters. Acknowledging relevant acts, guidelines and policies (at the time they were written), the CRWMS documents Watershed Scale and Subwatershed Scale, Objectives, Indicators and Targets. During the preparation of the Phase 1 Characterization report, the Endangered Species Act 2007 was proclaimed, and species Recovery Strategies are in various forms of preparation. The Subwatershed and Local Scale Goals and Objectives in the form the working Targets, via the Steering Committee have been developed through Phases 1 and 2 of the Subwatershed Study. The status of agreement by the Steering Committee is presented within Table 2.1. The watershed-scale goals, objectives and targets have been distilled to Landscape/Subwatershed/Local scales for use in developing land use (urban and Natural Heritage System), as well as management practices such as stormwater management, LID BMP s, watercourses, etc. When there has been disagreement on the targets, the Principles as established by the City, MNR, CVC and the MPLG have been used to assist in the interpretation and application of Goals, Objectives, and Targets to the Mount Pleasant Community. Table 2.1 notes where the MOU and SPNHS has achieved common ground and may be considered agreement on some unresolved targets. Natural Heritage System The final Secondary Plan Natural Heritage System (SPNHS) for the Mount Pleasant Community is the key management strategy that has been identified to address applicable provincial, municipal and agency policies, regulations and legislative requirements with respect to natural heritage conservation and management. These encompass: Development of complete compact communities; Sustainable development; Natural heritage system identification, protection, restoration and enhancement; Regulatory approvals for the protection, alteration and management of watercourses and floodplains, fish and wildlife habitat, and wetlands; and, Sustainable management practices for conventional and green infrastructure. Project Number:

8 Provincial Policy Statement - Updated Natural Heritage Manual (2010) Subsequent to the impact assessment of the 2G Plan, the Province released the Natural Heritage Reference Manual, 2 nd Edition (April 2010), which guides the application of the natural heritage policies of the PPS (2005). This revised edition recommends an approach for the identification of Natural Heritage Systems that builds on the 1999 version in referencing the system approach for NHS identification, first described in Riley and Mohr (1994), however there is increased detail and reference to more current scientific information to support the suggested approach. The NHRM updates the treatment of specific PPS-identified categories, including significant habitat of endangered and threatened species [now subject to a strengthened provincial Endangered Species Act (2007)], significant wetlands (now with greater focus on linkage to hydrological regimes, and subject to strengthened protection under updated Conservation Authority Regulations), significant woodlands (now recognized in some upper tier municipal Official Plans and subject to region-specific identification criteria), significant valleylands (now recognized as having cultural heritage value in addition to ecological and hydrological significance), significant wildlife habitat (planning authorities still encouraged to identify SWH on a comprehensive rather than site-by-site basis), significant areas of natural and scientific interest, and fish habitat. The updated NHRM also provides context on development of Natural Heritage Systems in settlement areas, whether in existing built-up areas, or in designated growth areas as defined in the PPS (2005); the new Edition was released after the completion of the MOU so does not directly apply. The guidance reflects that the province has also enacted the Places to Grow Act and related policies to promote more compact and efficient urban development, which place greater emphasis on higher population densities and well integrated land uses. The interpretation of this new legislation, in concert with the PPS, requires that well-defined NHS strategies be developed that balance protection of natural features and functions for the long term, with efficient land use approaches. In particular, the Second Edition of the Natural Heritage Reference Manual (MNR 2010) advises (Sect ): Every natural heritage system, however, will be different. There is no minimum size for a system or minimum percentage of a planning area or its natural features that must be included in the system. Therefore, the extent of the natural heritage systems identified in the noted examples represents what was appropriate and achievable in those situations. The SPNHS has addressed all of the key matters identified in the updated NHRM, and also reflects the scope of subwatershed targets that were developed through stakeholder participation with the intention to conform to provincial and municipal plans and policies, as well as recommendations arising from previous applicable watershed plans and subwatershed studies as prepared by Credit Valley Conservation. The SPNHS also reflects the strategic framework for a future NHS, mandated in the Terms of Reference that was developed in Phase 1, the subwatershed study process for the integration of information and data, analysis of impacts, and the specification of a recommended natural heritage system and associated land use plan. Project Number:

9 Conservation Authorities Act / Ontario Regulation 160/06. Under the Conservation Authorities Act, CVC administers Ontario Regulation 160/06: Regulation of Development, Interference with Wetlands and Alterations to Shorelines and Watercourses. Through this regulation, the CVC has the ability to prohibit, regulate or require the permission of the authority for development which may affect a wetland. They also regulate watercourses and development within defined distances from these regulated features. In the case of Block Plans 51-1 and 51-2, the CVC s regulated area includes watercourses, floodplains, wetlands and areas adjacent to these features. The extent of the regulated area depicted in Ontario Regulation 160/06 mapping is a preliminary interpretation of the regulated area. The regulated area is determined through the application of wording of Ontario Regulation 160/06. The Endangered Species Act Species at Risk are known to occur in the Fletcher s Creek and Huttonville Creek subwatersheds. The Committee on the Status of Species at Risk in Ontario (COSSARO) uplisted Redside Dace to endangered in 2009 under Ontario s Endangered Species Act, 2007 (ESA 2007). Bobolink, a migratory bird species of open country habitats, was listed as Threatened in Ontario in September The Endangered Species Act 2007 (ESA) protects both individuals of a species and its habitat. Section 9 prohibits the harm of individuals. Section 10 of the ESA prohibits damage or destruction of habitat of an endangered or threatened species. Section 17 of the ESA lists the conditions under which the Minister may issue a permit to contravene sections 9 or section 10. When a species is newly listed as endangered or threatened on the Species at Risk in Ontario (SARO) list, its habitat is also protected under the ESA The area of habitat protected is based on a general habitat definition found in the Act. The definition of general habitat is an area on which the species depends, directly or indirectly, to carry on its life processes, including life processes such as reproduction, rearing, hibernation, migration or feeding. This protection remains in place until a species-specific habitat regulation is created. Once a species-specific habitat regulation is created it replaces the general habitat described above. A recovery strategy, which provides advice to government, was published for Redside Dace in February, A draft government response statement was posted on the Environmental Registry in September, 2010, which summarizes the actions that the Government of Ontario intends to take in response to the strategy. A species-specific habitat regulation for redside dace is being prepared and will be posted on the Environmental Registry on February 18, 2011 (M. Heaton, personal communication, November 1, 2010). The draft government response statement indicates that the government will develop urban development guidelines to provide guidance where there is an interest in developing urban areas within Redside Dace habitat, as protected under the Endangered Species. These guidelines will be posted on the Environmental Registry on February 18, 2011 (M. Heaton, personal communication, November 1, 2010). There is currently no recovery strategy for Bobolink, and a draft is not anticipated before In the interim, we understand that determinations with respect to the habitat of Bobolink as interpreted under the ESA will require consultation on a case-by-case basis with MNR species Project Number:

10 at risk experts in Peterborough. The habitat typically utilized by Bobolink consists of open field areas, ideally in grassy cover, often related to hayfields, early old field succession or pasture related agricultural uses. The species is area-sensitive; that is it typically requires a minimum size of habitat to breed successfully. A key cause of its decline is early harvesting of hay crops, which destroys nests and fledglings. Fisheries Act The Fisheries Act states no person shall carry on any work or undertaking that results in the harmful alteration, disruption or destruction of fish habitat (Section 35(1)) unless authorized by the Minister of Fisheries and Oceans, or under regulations made by the Governor in Council under this Act (Section 35(2)). As well, no person shall deposit or permit the deposit of any deleterious substance into water frequented by fish (Section 36(3)). Stemming from the Fisheries Act, the Department of Fisheries and Oceans (1986) Policy for the Management of Fish Habitat has the objective of creating a net gain of habitat for Canada s Fisheries resources. The guiding principle to realize this end is no net loss which requires that if the productive capacity of a fish habitat is reduced, then a compensating increase in fish production must be made to occur. The Fisheries Act and supporting policy are discussed in more detail in Section LSA, Phase 1 and SPNHS Guidance As a companion study to the subwatershed study, the Landscape Scale Analysis (LSA) (Draft 2007) assessed the regional context of natural heritage constraints, priorities and opportunities, summarized as three principles for the development of a natural heritage system in Mount Pleasant: Principle 1: Wherever possible, incorporate natural features that contribute to flow moderation, water quality protection, and potential linkages to regional systems (Greenbelt / Escarpment, lower Credit R.), as well as air pollution management. Principle 2: Wherever possible, improve existing corridors, and create new corridors and linkages that integrate urban and natural heritage objectives and help to define wellplanned, densified development within the sub-watershed. Principle 3: Adopt urban designs that promote public familiarity and awareness of regional and local environmental features and functions. The finalized SPNHS will be referenced within the updated LSA once Phase 3 has been completed with the implementation details. The final LSA will also contain other changes that are under discussion by the Technical Steering Committee. These will not affect the SPNHS Plan which has been adopted and reflected in the approved Secondary Plan. Notably, the SPNHS has been refined through the Phase 2 Impact Assessment testing, specifically with the addition of a new corridor in the Fletcher s Creek headwater area, which will be acknowledged and addressed through the Block Plan OPA. Project Number:

11 The Phase 1 SWS study for Fletcher s and Huttonville Creeks collected field data on area resources and applied various analytical tools and procedures to develop an understanding of the features and functional processes currently within the study area, their associated sensitivities, and the opportunities for enhancement, restoration and connections. This included a multi-disciplinary examination of relationships between terrestrial, aquatic, hydrologic, hydrogeologic and stream channel resources. Section in Phase 1 identified a Natural Heritage Systems approach and a hierarchy of four potential NHS frameworks, ranging from traditional Islands of Green and Green Linkage approaches, to Linked Green Blocks and Green Development approaches which essentially reflect the evolution of development and natural heritage system planning practices in southern Ontario. The Linked Green Blocks and Green Development emphasize an integrated approach to recognize, protect, enhance and manage system level functions in the future urban landscape, and most effectively address current provincial, municipal and environmental agency plan, policy and regulatory requirements for a natural heritage systems planning. These more advanced approaches, supported by the LSA direction, and terrestrial (as well as other) targets, form the basis for preparation of management strategies affecting not only the identified SPNHS, but also the contributing functions or deficits of the new urban landscape.. As concluded in the Phase 2 impact assessment of the 3G Plan, the Mount Pleasant Community SPNHS reflects the protection of key existing natural features, the creation, restoration and/or maintenance of key natural functions and linkages, and the application of feature-specific buffers. Potential impacts were assessed against subwatershed targets which evolved from a watershed scale to a subwatershed scale through a consultative process involving the City, Credit Valley Conservation, Peel Region, Ministry of Natural Resources, DFO, Area Landowners, and other stakeholders. It has been recognized by the stakeholders, that some of the subwatershed targets would continue to be refined and/or qualified through the subsequent stages of the impact assessment. In Mayfield West in the Town of Caledon, located immediately north of Mount Pleasant, a preferred Secondary Plan is currently under consideration that would integrate with the SPNHS, providing linkage to natural features within the Huttonville and Fletcher s Creeks and Etobicoke Creek subwatersheds, and to the Greenbelt, in accordance with the local to regional scale functional priorities, and principles identified in the LSA. Phase 3 will guide the implementation of the SPNHS and its associated functional requirements, which will be addressed at a site-specific level by the Block Plan EIR studies. Given that the terrestrial targets were achieved, and opportunities substantially optimized under the 3G Plan (subject to key studies at the EIR level and detailed design based on Phase 3 recommendations), the 3G Plan upon implementation will need to be consistent with key policy criteria, regulations, and objectives including those of the PPS (2005), CVC Regulations, Region of Peel Official Plan, and Official Plan. Project Number:

12 Targets and Status of Agreement Consensus was not achieved among the stakeholders and Subwatershed study team on the following targets: Contaminants of Concern - unable to model concentrations; will achieve attainable loading rate reductions between current and future land use (to be better than current MOE Level 1 Enhanced standards), although CVC advocates working towards a zero net loading (i.e. no net increase in annual contaminant loading post-development). Forest cover and wetland cover - some agreement on achieving natural vegetation cover; key functional measures of future cover and diversity as represented by the SPNHS and Principles resolve these targets. Although not an issue of consensus, Table 2.1 has been amended to recognize Bobolink, as a Species at Risk, currently listed as Threatened in Ontario in autumn This matter will require consultation with MNR. Project Number:

13 Objective Indicator Results 4c 5b 9d-k Flow Time Series Instream Erosion Potential 2 Contaminants of Concern Ratio of flows has been mostly maintained. Low flow durations have been marginally reduced, while mid-range flow durations have increased slightly. Peak flows have been maintained. Erosion thresholds have been calculated for sites both within and outside of the North West Brampton study area. Exceedences of erosion critical flows have been maintained. Contaminants loadings with LID would be better than Level 1 treatment (Enhanced Standard) Table 2.1. Phase 2 Impact Assessment Target Summary and 3G Plan Directives System Integration Source Pathways Receptors Linkage SURFACE WATER Linked impact pathways: Stable Bed Sediment Regime (5c) Low Flow Function (NEW 4) Linked impact receptors: Protection of Life & Property (7a & NEW 1) Fish Communities (16a) Fish Productive Capacity (16b) Species at Risk (aquatic) (16c) Riparian cover (15a and 15b) Species at Risk (aquatic) (16c) Benthic Invertebrate Community (New13) Linked impact pathways: Stable Bed Sediment Regime (5c) Low Flow Function (NEW4) Linked impact receptors: Protection of Life & Property (7a & NEW 1) Fish Communities (16a) Fish Productive Capacity (16b) Species at Risk (aquatic) (16c) Benthic Invertebrate Community (New13) Riparian cover (15a and 15b) Loadings with LID would be better than Level 1 treatment protection. Linked impact receptors Fish Communities (16a) Fish Productive Capacity (16b) Species at Risk (aquatic) (16c) Benthic Invertebrate Community New13) Potential Impacts to 3G Plan (Land Use/Management Practices) No change required No change required No change required Current Status and relevant MOU comments Agreed to proposed ratio of 1.0 or less. (Note: Landowner s support a ratio of 1) Agreed Modelling not concentration based. Preferred approach to determine attainable loading rate reductions between current and future land use (with SWM) Agreed to approach based on loadings not concentrations. Study using current MOE Level 1 Enhanced as the minimum standard for stormwater management. CVC advocates working towards a zero net loading (i.e. no net increase in annual contaminant loading postdevelopment). The MOU notes that acceptable LID BMP s may be determined through consultation with the City and CVC, and increased topsoil depth is Project Number:

14 Objective Indicator Results 7a NEW 1 Protection of Life and Property Protection of Life and Property (2 to 100 year Peak flows) 100yr flow control provided. Regional Storm Hurricane Hazel flood control (post-pre) results in significant volume requirements. 2 to 100 Year Post-development Peaks meet Pre-development Table 2.1. Phase 2 Impact Assessment Target Summary and 3G Plan Directives System Integration Source Pathways Receptors Linkage Channel dimensioning incorporated into fluvial design to accommodate storage. Peak flows maintained, required input into fluvial design. Potential Impacts to 3G Plan (Land Use/Management Practices) Based on meander belt and hydraulics the following channel corridors widths would be required: West /- Central Eastern - 55m +/- Central Western 55m+/- Eastern 55m+/- McLaughlin Road 55m+/- No change required Current Status and relevant MOU comments considered the primary LID. Agreed Agreed 8b 8c Groundwater Discharge Recharge Areas Potential decreases in local groundwater discharge may occur without LID measures. The overall baseflow demonstrated increases based on modeled LID measures. Various local reaches have slight gains or losses with a general increase in more discharge areas. 18% decrease in recharge in both Huttonville and Fletcher s without LID but potential increase with LID Linked impact receptors: Fish Communities (16a) Fish Productive Capacity (16b) Species at Risk (aquatic) (16c) Benthic Invertebrate Community (New 13) Linked impact receptors: Fish Communities (16a) Fish Productive Capacity (16b) Species at Risk (aquatic) (16c) Benthic Invertebrate Community (New 13) No change required No change required Agreed to be Functionally related. MOU notes that Long-term monitoring such as groundwater monitoring wells and piezometers data will be used in adaptive management Agreed to be Functionally related. MOU notes that Long-term monitoring such as groundwater monitoring wells and piezometers data will be used in adaptive management 8d Water Table Elevations General decrease up to 50cm without LID. Local wet features are not groundwater derived but potential for small increase in recharge (infiltration) out of these features. Application of LID shows a potential increase in the water table. No impacts to water supply wells. Provides hydraulic gradients for linkages noted above and maintains water levels for local domestic wells. Offset potential impact of local lowered water table by encouraging overland drainage to existing wetland areas from both park area and clean urban drainage (rooftops and FDC s) Agreed to be Functionally related. MOU notes that Long-term monitoring such as groundwater monitoring wells and piezometers data will be used in adaptive management Project Number:

15 Objective Indicator Results Table 2.1. Phase 2 Impact Assessment Target Summary and 3G Plan Directives System Integration Source Pathways Receptors Linkage Potential Impacts to 3G Plan (Land Use/Management Practices) Current Status and relevant MOU comments 16a b c Healthy fish communities, appropriate for the habitats Overall Fish Productive Capacity Species at Risk (Redside Dace) Redside Dace - Maintenance of groundwater discharge, enhanced riparian buffers, increases in forest cover expected to benefit Redside Dace. Potential exists for upstream expansion of redside dace habitat. Water temperature to be addressed through BMPs; Water quality meets or exceeds Enhanced Level standard with LID measures. Bobolink Subject to consultation with MNR. No Recovery Strategy available. Linked impact pathways: Flow Time Series (4c) Instream Erosion Potential 2 (5b) Stable Bed Sediment Regime (5c) Low Flow Function (NEW4) Contaminants of Concern (5d-k) Groundwater Discharge (8b) Recharge Areas (8c) Maintenance of drainage density (NEW 2) Protection of Property and Structures (meander belt) Riparian Cover 1 (15a) Riparian Cover 2 (15b) Linked impact pathways: Flow Time Series (4c) Instream Erosion Potential 2 (5b) Stable Bed Sediment Regime (5c) Low Flow Function (NEW 4) Contaminants of Concern (5d-k) Groundwater Discharge (8b) Recharge Areas (8c) Maintenance of drainage density (NEW 2) Protection of Property and Structures (meander belt) Riparian Cover 1 (15a) Riparian Cover 2 (15b) Linked impact pathways: Flow Time Series (4c) Instream Erosion Potential 2 (5b) Stable Bed Sediment Regime (5c) Low Flow Function (NEW 4) Contaminants of Concern (5d-k) Groundwater Discharge (8b) Recharge Areas (8c) Maintenance of drainage density (NEW 2) Protection of Property and Structures (meander belt) Riparian Cover 1 (15a) Riparian Cover 2 (15b) No change required. No change required No changes to 3G land use plan. Further refinement to upstream management practices and design during subsequent stages (Phase 3/CFCP/EIR). Not a specific target to be evaluated in Phase 2; intended to guide recommendations on Phase 3 implementation. MOU notes that a CFCP is to be implemented separate to the Subwatershed Study Not a specific target to be evaluated in Phase 2; intended to guide recommendations on Phase 3 implementation. MOU notes that a CFCP is to be implemented separate to the Subwatershed Study Agreed regarding Redside Dace; Bobolink is a new matter to be resolved. Project Number:

16 Objective Indicator Results NEW 13 Benthic Invertebrate Community Table 2.1. Phase 2 Impact Assessment Target Summary and 3G Plan Directives System Integration Source Pathways Receptors Linkage Linked impact pathways: Flow Time Series (4c) Instream Erosion Potential 2 (5b) Stable Bed Sediment Regime (5c) Low Flow Function (NEW 4) Contaminants of Concern (5d-k) Groundwater Discharge (8b) Recharge Areas (8c) Maintenance of drainage density (NEW 2) Protection of Property and Structures (meander belt) Riparian Cover 1 (15a) Riparian Cover 2 (15b) Linked impact receptors: Fish Communities (16a) Fish Productive Capacity (16b) Species at Risk (aquatic) (16c) Potential Impacts to 3G Plan (Land Use/Management Practices) No changes to 3G land use plan. Further refinement to management practices and design during subsequent stages (Phase 3/CFCP/EIR). Current Status and relevant MOU comments Not a specific target to be evaluated in Phase 2; intended to guide recommendations on Phase 3 implementation. Monitoring of benthic invertebrates will be a key component of the evaluation of the new NHS and its implementation. NEW 2 5c 6a Maintenance of drainage density Stable Bed Sediment Regime Protection of Property and Structures Linked impact pathways: Natural Corridors & Linkages (NEW 6 & 7) Linked impact receptors: Riparian cover (15a and 15b) Fish Communities (16a) Fish Productive Capacity (16b) Species at Risk (aquatic) (16c) Benthic Invertebrate Community (New13) Linked impact receptors: Other fluvial targets Riparian cover (15a and 15b) Fish Communities (16a) Fish Productive Capacity (16b) Species at Risk (aquatic) (16c) Benthic Invertebrate Community (New 13) Linked impact pathways: Natural Area Protection (NEW 5) Linked impact receptors: Riparian cover (15a and 15b) Fish Communities (16a) Fish Productive Capacity (16b) Species at Risk (aquatic) (16c) Benthic Invertebrate Community (New13) Need to ensure incorporation of appropriate swales within the 3G Plan using an approach similar to that demonstrated through the impact assessment. Additional swales within Fletchers Creek should be sought in private lands. Creation of natural channels and swales that do not flow through SWM facilities should help maintain stable bed sediment regime. Channel design and subsequent channel management practices should encourage the delivery of natural sediment supply. Based on meander belt and hydraulics the following channel corridors widths would be required: West /- Central Eastern - 55m +/- Central Western 55m+/- Eastern 55m+/- McLaughlin Road 55m+/- In addition a new corridor should be Although it is noted that the landowners group disagree with the use of drainage density as a management tool, an implementation approach has been formalized and agreed for this target. Agreed Agreed Project Number:

17 Objective Indicator Results NEW 3 NEW 4 Flushing Flow (sediment mobility) Low flow function Table 2.1. Phase 2 Impact Assessment Target Summary and 3G Plan Directives System Integration Source Pathways Receptors Linkage Linked impact receptors: Fish Communities (16a) Fish Productive Capacity (16b) Species at Risk (aquatic) (16c) Benthic Invertebrate Community (New 13) Linked pathways: Stable bed sediment regime (5c) Linked impact receptors: Fish Communities (16a) Fish Productive Capacity (16b) Species at Risk (aquatic) (16c) Benthic Invertebrate Community (New 13) Potential Impacts to 3G Plan (Land Use/Management Practices) considered at the north west corner of Mayfield and McLaughlin to connect the drainage feature north of Mayfield to the watercourse east of McLaughlin. No impact to land use - to be refined/ applied in Block Plan EIRs and detail design to inform proposed channel design where riffle features or to be created/maintained (coarse sediment). No impact to land use - achievement of this target will need to be demonstrated through design of the proposed channels and swales in subsequent phases. Of key importance is maintenance of a defined thalweg within the channel that will help maintain conveyance of flow and sediment within the lower range of flows Current Status and relevant MOU comments General agreement to be applied through Block Plan EIRs and detailed design General agreement to be applied through Block Plan EIRs and detailed design 15a Riparian Cover 1 Target achieved under 2G Plan. SPNHS achieves minimum 15m setbacks for warmwater streams and 30m setbacks for cool/coldwater streams. Also meander belt plus 30 m setback for Redside dace habitat. Linked pathways: Riparian cover (15b) Forest Cover (15c) Wetland Cover (15d) Interior Forest (15e) Natural Area Protection (NEW 5) Natural Corridor & Linkages (NEW 6) Linked impact receptors: SAR/Species of Concern (16c) Vegetation Communities (16d) Significant Woodlands (NEW 10) Recharge areas (8d) Protection of life and property (NEW 1) Suspended solids (1i) Healthy fish communities (16a) Fish Communities (16a) Fish Productive Capacity (16b) Species at Risk (aquatic) (16c) Benthic Invertebrate Community (New 13) A wide range of riparian vegetation types are envisaged in the SPNHS and these will require consideration in Phase 3 and Block Plan EIRs. Agreed Project Number:

18 Objective Indicator Results 15b 15c Riparian Cover 2 Forest Cover Target achieved under 2G Plan. All retained streams will be buffered by natural vegetation Target achieved under 2G Plan. Increasing natural cover from 7.9% to 16.9%. The 2G Plan offers a well connected system that is highly integrated on a functional level. Table 2.1. Phase 2 Impact Assessment Target Summary and 3G Plan Directives System Integration Source Pathways Receptors Linkage Linked pathways: Riparian cover (15a) Forest Cover (15c) Wetland Cover (15d) Interior Forest (15e) Natural Area Protection (NEW 5) Natural Corridor & Linkages (NEW 6) Linked impact receptors: SAR/Species of Concern (16c) Vegetation Communities (16d) Significant Woodlands (NEW10) Recharge areas (8d) Protection of life and property (NEW 1) Suspended solids (1i) Healthy fish communities (16a) Fish Communities (16a) Fish Productive Capacity (16b) Benthic Invertebrate Community (New 13) Linked pathways: Wetland Cover (15d) Interior Forest (15e) Natural Area Protection (NEW 5) Natural Corridor & Linkages (NEW 6) Multi-Functional Supporting Linkage (NEW 7) Linked impact receptors: SAR/Species of Concern (16c) Vegetation Communities (16d) Significant Woodlands (NEW 10) Recharge areas (8d) Protection of life and property (NEW 1) Suspended solids (1i) Healthy fish communities (16a) Baseflow in streams (8a) Stable bed sediment regime (5c) Potential Impacts to 3G Plan (Land Use/Management Practices) A wide range of riparian vegetation types are envisaged in the SPNHS and these will require consideration in Phase 3 and Block Plan EIRs. Type of natural cover within the NHS will require consideration in Phase 3 and Block Plan EIRs. See also Target NEW 6. Current Status and relevant MOU comments Credit River Fisheries Management Plan indicates buffer requirements are for permanent and seasonal fish habitat. MOU notes that buffers will be allowed to naturally regenerate Agreement was not achieved on this target, however it is agreed that the SPNHS system is improved over existing conditions and over the POD Plan.The MOU notes that within the East Huttonville portion of the SPNHS extent of habitat enhancement and wetland is to be implemented as per the concepts/principles illustrated on the Landowner s vignettes. Project Number:

19 Objective Indicator Results 15d 15e 16c Wetland Cover Interior Forest/Core Habitat Species At Risk and Special Status Species Target achieved under 2G Plan increase from 1% to 5.5% wetland cover. Target achieved under 2G Plan, Increase in Interior Forest from 0.2% to potential maximum of 1.2%. Target for Redside Dace predicted to be achieved under 3G Plan; treatment of Bobolink subject to consultation with MNR Table 2.1. Phase 2 Impact Assessment Target Summary and 3G Plan Directives System Integration Source Pathways Receptors Linkage Linked pathways: Forest Cover (15c) Interior Forest (15e) Natural Area Protection (NEW 5) Natural Corridor & Linkages (NEW 6) Multi-Functional Supporting Linkage (NEW7) Linked impact receptors: SAR/Species of Concern (16c) Vegetation Communities (16d) Significant Woodlands (NEW 10) Recharge areas (8d) Protection of life and property (NEW 1) Suspended solids (1i) Healthy fish communities (16a) Stable bed sediment regime (5c) Linked pathways Natural Area Protection (NEW 5) Natural Corridor & Linkages (NEW 6) Multi-Functional Supporting Linkage (NEW 7) Linked impact receptors: SAR/Species of Concern (16c) Recharge areas (8d) Protection of life and property (NEW 1) Linked pathways: Forest Cover (15c) Wetland Cover (15d) Natural Area Protection (NEW 5) Natural Corridor & Linkages (NEW 6) Linked impact receptors: Interior Forest (15e) Healthy fish communities (16a) Vegetation Communities (16d) Significant Woodlands (NEW 10) Potential Impacts to 3G Plan (Land Use/Management Practices) A wide range of wetland types are envisaged in the SPNHS and these will require consideration in Phase 3 and Block Plan EIRs. See also Target NEW 5. Ultimate interior habitat achieved is dependent upon location and extent of forest cover added over time as part of the Phase 3 recommendations, subsequent Block Plan EIRs, and open space management by the City. A wide range of habitat types are envisaged in the SPNHS and these will require consideration in Phase 3 and Block Plan EIRs. See also Target NEW 5. Current Status and relevant MOU comments Agreement was not achieved on this target, however it is agreed that the SPNHS system is improved over existing conditions and over the POD Plan. The MOU notes that within the East Huttonville portion of the SPNHS extent of habitat enhancement and wetland is to be implemented as per the concepts/principles illustrated on the Landowner s vignettes. Agreed Agreed on Redside Dace; Bobolink is a new SAR matter Project Number:

20 Objective Indicator Results 16d NEW 5 Vegetation Communities Natural Area Protection Target achieved under 2G Plan. Target achieved under 2G Plan. Proposed buffer system of 10m from staked dripline of woodlands, 20m from staked limit of wetlands, Table 2.1. Phase 2 Impact Assessment Target Summary and 3G Plan Directives System Integration Source Pathways Receptors Linkage Linked pathways: Riparian cover (15a/15b) Forest Cover (15c) Wetland Cover (15d) Natural Area Protection (NEW 5) Natural Corridor & Linkages (NEW 6) Multi-Functional Supporting Linkage (NEW 7) Linked impact receptors: Interior Forest (15e) SAR/Species of Concern (16c) Significant Woodlands (NEW 10) Suspended solids (1i) Healthy fish communities (16a) Protection of life and property (NEW 1) Stable bed sediment regime (5c) Linked pathways: Riparian cover (15a/15b) Forest Cover (15c) Wetland Cover (15d) Natural Corridor & Linkages (NEW 6) Multi-Functional Supporting Linkage (NEW 7) Linked impact receptors: Recharge areas (8d) Interior Forest (15e) SAR/Species of Concern (16c) Vegetation Communities (16d) Significant Woodlands (NEW 10) Suspended solids (1i) Healthy fish communities (16a) Protection of life and property (NEW 1) Stable bed sediment regime (5c) Potential Impacts to 3G Plan (Land Use/Management Practices) Strategies will be necessary to manage vegetation community diversity in the long term, through Phase 3 recommendations, Block Plan EIRs, and open space management by the City. Community cover along riparian corridors will need to consider runoff conveyance, fluvial and fisheries implications. Additional functional protection may be gained through complementary land uses. Buffer implementation and management strategies to be addressed through Phase 3 recommendations and Block Plan EIRs. Current Status and relevant MOU comments Agreed Agreed to under MOU; Project Number:

21 Objective Indicator Results NEW 6 NEW 7 Natural Corridors and Linkages Corridor Type 2 Multi-Functional Supporting Linkage Target achieved under 2G Plan. Dedicated corridor widths of 45 to 100m, and net corridor widths of m throughout most of the East Huttonville Creek system. Applied where feasible in SPNHS. Stream corridor-based NHS reinforced through placement of supportive land uses. Strengthened connections northward to the existing east-west Etobicoke Creek valley corridor in Town of Caledon. Table 2.1. Phase 2 Impact Assessment Target Summary and 3G Plan Directives System Integration Source Pathways Receptors Linkage Linked pathways: Riparian cover (15a/15b) Forest Cover (15c) Wetland Cover (15d) Natural Area Protection (NEW 5) Multi-Functional Supporting Linkage (NEW 7) Linked impact receptors: Recharge areas (8d) Interior Forest (15e) SAR/Species of Concern (16c) Vegetation Communities (16d) Significant Woodlands (NEW 10) Suspended solids (1i) Healthy fish communities (16a) Protection of life and property (NEW 1) Stable bed sediment regime (5c) Linked pathways: Riparian cover (15a/15b) Forest Cover (15c) Wetland Cover (15d) Natural Area Protection (NEW 5) Natural Corridor & Linkages (NEW 6) Linked impact receptors: Recharge areas (8d) Interior Forest (15e) SAR/Species of Concern (16c) Vegetation Communities (16d) Significant Woodlands (NEW 10) Suspended solids (1i) Healthy fish communities (16a) Protection of life and property (NEW 1) Stable bed sediment regime (5c) Potential Impacts to 3G Plan (Land Use/Management Practices) Locations of trails, road crossings, and planning of corridor interfaces at Wanless Drive and Mayfield Road to be further clarified in the Block Plan EIRs. Final locations, configurations, and specialized components of SWM facilities (FDC s, swale compensation, habitat elements) to be further clarified in the Block Plan EIRs. Current Status and relevant MOU comments Agreed to under MOU; Agreed to (where feasible) under MOU Project Number:

22 Objective Indicator Results NEW 10 Significant Woodlands Target Achieved under 2G Plan Table 2.1. Phase 2 Impact Assessment Target Summary and 3G Plan Directives System Integration Source Pathways Receptors Linkage Linked pathways: Riparian cover (15a/15b) Forest Cover (15c) Wetland Cover (15d) Natural Area Protection (NEW 5) Natural Corridor & Linkages (NEW 6) Linked impact receptors: Recharge areas (8d) Interior Forest (15e) SAR/Species of Concern (16c) Vegetation Communities (16d) Suspended solids (1i) Healthy fish communities (16a) Protection of life and property (NEW 1) Stable bed sediment regime (5c) Potential Impacts to 3G Plan (Land Use/Management Practices) Management strategies to be proposed in the Phase 3 recommendations, and subsequent Block Plan EIRs. Current Status and relevant MOU comments Landowners support the protection of identified features under the MOU Project Number:

23 2.2 Summary of Management Practices Discipline-specific management practices have been developed using an integrated perspective related to all disciplines, based on the results of the Impact Assessment (specifically for the 2G and 3G land use) and how the subwatershed goals, objectives and related targets have been met. The following provides a Summary of the Mount Pleasant Community-specific management practices with associated planning and/or implementation recommendations Hydrogeology The Phase 2 Impact Assessment for groundwater carried out a modelling exercise to quantify, within the limitations of the FEFLOW steady state model and its input parameters, the potential changes in the groundwater levels, changes to groundwater flow directions and subsequent changes in groundwater discharge to local stream reaches. It should be noted that based on field monitoring and assessment, the area wetlands are surface water driven, hence not supported by groundwater discharge. The potential changes in water levels resulted from the potential reduction in unmitigated recharge and the lowering and realignment of the streams. The modelling exercise and related groundwater quantity impact considerations presented the following conclusions: The simulated potential impacts to the groundwater flow system (water table lowering, reduction in groundwater discharge) that may occur as a result of the 3G land use using Business-As-Usual/conventional storm water management practices have the potential to be reduced and possibly enhanced using LID management practices. The change in groundwater discharge is small on a subwatershed basis. Within the Mount Pleasant area a potential reduction in groundwater discharge of 16% may occur without the application of LID BMP s with a potential 3% increase with the application of LID BMP s. Simulated groundwater discharge locations are generally maintained. The lowering of the groundwater levels could potentially increase infiltration to the groundwater flow system from the recharge functioning terrestrial units or reduce discharge, seasonal or otherwise where observed in the more site specific studies. The increase in local recharge is expected to be small due to the low hydraulic conductivity of the underlying sediments and could likely be compensated by directing additional clean runoff to the wetlands if the increased leakage rate is expected to have an adverse impact on the terrestrial features. The reduction in groundwater levels is not expected to impact the local water wells. The lateral extent of the modeled water table lowering due to the stream realignment and lowering may be a function of the representation of the sand and gravel layer in the model or the steady state nature of the model along with representation of the active weathered zone. The lateral extent of the water table drawdown may be much less as presented in the empirical equation for trench dewatering. Project Number:

24 It is also important to note, along with the modeling limitations discussed below, that the modeling represents a steady state condition and could take a substantial amount of time to reach these conditions. In a temporal sense, this may be considered worst case. Transient events both on an event scale and a seasonal scale may allow for more recharge to occur. Another important factor which has not been included in the modeling exercise, concerns the additional recharge that may occur in the developed area due to the importation of lake based water and related irrigation and leakage from water infrastructure Groundwater Quantity The management of groundwater quantity primarily focuses on the maintenance of groundwater levels where those levels are functionally significant to provide water to terrestrial units, provide the necessary hydraulic gradient to maintain groundwater discharge to stream and wet terrestrial features and to maintain water levels for local water wells. The primary management practices to maintain recharge involve stormwater management and the ability under various levels of development to maintain the spatial and possibly temporal nature of infiltration. Where the groundwater levels control a more intermediate or regional system the spatial and temporal infiltration characteristics may only have to be considered on a large areal scale and time frame so that averages are met. Within the perspective of locally driven groundwater flow systems the infiltration practices may have to emulate the shorter term local infiltration. LID best management practices which provide the capture to reduce stormwater runoff promote, in part, infiltration of various proportions of water into the ground. The HSP-F Water Quality model provided the recharge parameters to the FEFOW model (Sections 4.2 and Phase 2). The potential change in water levels resulting from the stream realignment and lowering is presented in Phase 2, Figure 3G-GW-8. The water table rise occurs as a result of the modelling constraint for closing of the outlet to the stream. The water table lowering is a result of the new stream invert intercepting the water table and the subsequent local drainage. The lateral extent of this stream influence is briefly discussed above. The reduction in the water table due to the 3G land and stream realignment is shown in Phase 2, Figure 3G-GW-12 and the subsequent change in water table from existing simulated conditions with the application of LID is shown in Phase 2, Figure 3G-GW-16. A comparison of the two figures, total Mount Pleasant recharge (Table 3.2.4, Phase 2) and simulated groundwater discharge (Table 3.2.2, Phase 2) demonstrates that the water table lowering due to a reduction in recharge and the subsequent potential reduction in discharge can be managed through LID management practices. Although not always practical the compaction of the Halton Till should be minimized. Compaction will reduce infiltration. Over time as the water table goes through the seasonal Project Number:

25 variations the original weathered nature would be expected to return. Removal of the upper active zone would likely be more significant and this should be minimized. The subtle hummocky topography contains local runoff and promotes a level of infiltration. Maintaining this topography would therefore be recommended where practical. Soil depth and the development of a hummocky topography would add to the natural infiltration. The installation of infrastructure should not intercept critical groundwater flow which may discharge to local receptors. It is expected that very local shallow groundwater flow systems may be reoriented but not at the expense of discharge or an unacceptable lowering of water levels. The same issue holds for construction dewatering. Prior to dewatering or the expectation of infrastructure drainage, an assessment should be carried out as to the potential for unacceptable impacts on the groundwater flow system and its linkages to determine what mitigative practices may be necessary Groundwater Quality A groundwater quality impact assessment was not modelled numerically but a hydrogeologic sensitivity map was developed using current provincial standards. The Intrinsic Susceptibility Index (ISI) is an index value that estimates the susceptibility of a given aquifer to contamination at a given point. ISI values were calculated using the 3D geologic model developed as part of the CVC Water Budget Project, which defines the elevation of the each aquifer within the North West Brampton Study area. The approach used is defined in the Source Protection Guidance Module (MOE, 2006) for Aquifer Vulnerability. ISI is calculated as the sum of the product of the thickness and hydraulic conductivity (as a K-factor (- log of K in m/s) of each geologic unit overlying an aquifer. The resulting ISI values are then classed into one of three groups (high (<30), medium (30-80) or low (>80)). Therefore high numbers represent low aquifer susceptibility/vulnerability and low numbers represent areas of high aquifer susceptibility. Within the Mount Pleasant study area the aquifer sensitivity was generally considered high. This reflects the thin overburden in places and the potential weathered zone. Although this area is considered relatively sensitive it should be noted that there is a significant level of protection from the fine grained Halton till when compared to a surficial sand aquifer. In areas where there is s more significant thickness of massive till the underlying units has reasonable protection. The ISI as such is conservative. The Mount Pleasant study area is not within any wellhead protection areas and the hydrogeologic units are not considered regional aquifers but local water wells currently exist in the overburden and underlying shale. Basic groundwater quality management should be considered which would include: Spills management plan Location consideration for underground storage tanks and mandatory groundwater quality monitoring associated with underground storage tanks, The appropriate abandonment of unused water wells and maintenance of existing water wells (Regulation 903, Ontario Water Resources Act) Effectively manage road de-icing and locations of snow dumps, Project Number:

26 Keep an ongoing contaminant threats inventory, Minimize application of lawn chemicals Hydrology/ Hydraulics General The calibrated HSP-F continuous hydrologic model developed as part of the Phase 1 SWS characterization and integration stage has been used in Phase 2 as the basis for conducting the Impact Assessment to provide an indication of subwatershed response to rainfall and snowmelt. The 3G impact assessment has been premised on the 3G land use (ref. Phase 2 Figure 3G Hutt LU) and respective hydrologic and hydraulic modelling. The 3G impact hydrologic assessment has assessed stormwater management using three scenarios as per the following: No stormwater management; Business as usual (conventional stormwater management), and Stormwater management with LID (low impact development best management practices) The Conventional Stormwater Management Scenario considers typical end-of-pipe stormwater management facilities, such as wetlands and wet ponds. The Stormwater management with LID BMPs Scenario considers end-of-pipe measures, plus generic LID best management practices applied at source. The LID BMP scenario modelling has used storage units, which have an infiltration component, a sub-drain component and an overflow component. The infiltration capacity of the existing soils has been set in the range of 0.38 mm/hr to 4.5 mm/hr based upon direction/findings from the hydrogeologic assessment. The generic LID storage units have been set-up using the HSP- F model RCHRES element with multiple outlets, to appropriately simulate generic infiltration LID measures. The Implementation Principles reference the use of increased topsoil depth (above conventional depths) as being one of the preferred LID BMPs. It states that, LID requirements will be met primarily through measures such as increased topsoil depth in appropriate locations. Other appropriate methods may also be determined through the EIR and Block Plan process, however these require approval by the City in consultation with Credit Valley Conservation. The Land Owner Consultant Team conducted additional analyses (ref. Phase 2 Appendix I ) which documents the effectiveness of the use of increased topsoil depths on lots. Based on the results of the hydrologic modelling and the degree that the stormwater related subwatershed targets and objectives have been met, the 3G Land Use Assessment Stormwater Management with LID Plan has been established as the basis for the stormwater management strategy for flooding and erosion control using a distributed network of stormwater management facilities and LID BMP s. Project Number:

27 The results of the analyses completed using the HSP-F water quality/water balance model for the 3G assessment indicated that LID BMP s located on residential properties and capturing the equivalent of between 0.96 to 1.73 mm per hectare (excluding road right-of-ways) would be sufficient to maintain the groundwater recharge and overall water balance at existing levels. The residential LID measures are currently not modelled to capture the driveway and pervious areas draining directly to the municipal right-of-way, they have been assumed to capture the runoff from the rooftops and the pervious areas on the residential lots. Table 2.2 provides the capture rates applied for the various land uses within the Mount Pleasant Community and for the future Huttonville Creek development area west of Mississauga Road. While the contributing drainage areas to the LID BMP are proposed to be located entirely within private properties and do not include the Public right-of-way or any directly connected impervious surfaces, the capture rates provided in Table 2.2 have been expressed in mm per hectare of land use (including the right-of-way) rather than mm per impervious hectare, in order to maintain consistency with conventional practice. These depths are used to calculate the volume required on the private property in order to work toward achieving a balance in the groundwater recharge for the full post-development land use, including the right-of-way and the associated directly connected impervious area. Table 2.2. LID BMP Capture Rates by Land Use Land Use Capture Rate (mm) Commercial Big Box 1.73 Strip Commercial 1.73 Small Institutional 0.64 Industrial Big Box 1.73 Prestige Industrial 1.73 Low Density Residential 1.04 Medium Density Residential 0.96 The unitary capture depths for each land use (i.e. depth per hectare of land use) as provided in Table 2.2 have been used in order to generate unitary volumes (i.e. volume per hectare) to be applied for each land use. For low and medium density residential land uses, LID infiltration BMP volumes per residential lot, have been calculated based upon the information provided in Table 2.2, as well as the following information for contributing drainage areas on low and medium density residential lots, which is based upon typical lots and right-of-way information provided by Urbantech Consulting (ref. Phase 2, Appendix I ) as per Table 2.2 a. Table 2.2a: Proportion of Land Use Element/Component Within Residential Land Use (%) Land Use Component/Element Low Density Residential Medium Density Residential Roof Lawn Driveway 11 6 Road NOTE: Numbers in italics represent components/elements draining to LID BMP Project Number:

28 The resulting capture volumes by land use are summarized in Table 2.2 b. Table 2.2b: LID BMP Volumetric Requirements by Land Use Land use LID Infiltration BMP Volume (m 3 /ha) Approximate Number of Lots per Hectare LID Infiltration BMP Volume (m 3 /lot) Low Density Residential Medium Density Residential Commercial 17.3 n/a n/a Retail/Strip Mall 17.3 n/a n/a School 6.4 n/a n/a Worship 6.4 n/a n/a Schools, Places of Worship, and other institutional and open space land uses are encouraged to apply contemporary land use and stormwater management practices to address impacts to the runoff regime. These land uses do not represent a large component of the Mount Pleasant community. Notwithstanding, the visible nature of these land uses within the community, the application of specific LID BMP would serve to better inform and educate area residents on the benefit and value of Low Impact Development and thus is strongly encouraged. In addition, while not explicitly modelled, other opportunities for LID BMP s should be encouraged to landowners through both a new homeowner educational package and City environmental efforts including: means to treat a portion of residential driveways, public LID BMP s, rainwater harvesting and other complementary measures. Flood Control Storage-discharge relationships for each of the off-line stormwater management facilities have been determined to control future peak flows to existing peak flows at the key comparison locations for the storm events up to, and including the 100 year storm. Table 2.3 provides the storage requirements for flood control. Table 2.3 Summary of Stormwater Management Requirements for Flood Control. Stormwater Management Scenario Conventional LID Drainage Outlet Unitary Storage Volume (m 3 /Impervious ha) 25-Year Unitary Discharge (m 3 /s/ha) Unitary Storage Volume (m 3 /Impervious ha) 100-Year Unitary Discharge (m 3 /s/ha) HW HE F F F F HW HE F F F F Project Number:

29 To mitigate the increase in peak flows, Regional Storm Flood Control Storage would also have to be provided at strategic on-line locations within East Huttonville Creek and Fletcher s Creek. Regional Storm storage as cited in Table 2.3 has been determined based on Ministry of Natural Resources guidelines; therefore stormwater management quantity storage required in the absence of any off-line/local stormwater management (i.e. to the 100 year standard), as per MNR protocol. The volume has been prescribed as on-line within tributary watercourse corridors. Hydraulics Table 2.4 Regional Storm Event Flood Storage Creek Storage Type Storage (m 3 /imp.ha) Total Storage (m 3 ) HW 2. On-line SWM ,000 HE 2. On-line SWM ,000 F1 3. Off-line SWM ,500 F2 2. On-line SWM ,000 F3 1. NA 0 0 F4 3. Off-line SWM , year governs. 2. Storages do not include 100 year offline facility storage. 3. Storages include 100 year facility storage. Regional Storm on-line storage would be provided within the Regulatory channel corridors, which have been assessed for flood hydraulics and stream morphology along with required setbacks. Accordingly Table 2.5 provides the required channel corridor widths. East Huttonville Fletcher s Table 2.5. Minimum Watercourse Channel Block Width Requirements (m) Creek Location South of CNR (ref. Reach HV 18, Fig. 1.1) North of CNR to TCPL (ref. Reaches HV 19, Fig. 1.1) TCPL to Wanless (ref. Reaches HV20-25), Fig. 1.1) North of Wanless to Woods (ref. Reaches HV 26, Fig. 1.1) North of Wanless, Woods to Mayfield (ref. Reaches HV 27-29, Fig. 1.1) West and Central Eastern Corridors (ref. Reaches F04, Fig. 1.1) Central Western Corridor (ref. reaches F 07-F08, Fig. 1.1) Eastern Corridor (ref. Reaches F15 F17, Fig. 1.1) Mayfield/ McLaughlin Corridor (ref. Reach F22, Fig. 1.1) Stream Meander Belt Flood Control Additional Buffer/Setback 2. Total / / / / / / / / /- 45 +/ /- 55 +/ / / / / / /- Note: The implementation of this buffer/setback can be variable/flexible as it relates to its application to the corridor, e.g. if its 10 m, it might be split 5 m on either side, or used as 6 metres on one side to facilitate the City trail and 4 m on other side. 1. Actual watercourse corridors can be greater based on SPNHS principles. 2. This buffer/setback may be variable/flexible as applied from top-of-bank (e.g. 5 m per side). Project Number:

30 Riparian storage has been determined for the respective channel corridors noted in Table 2.6. The EIRs will have to demonstrate that the proposed creek corridors will maintain the existing riparian storage, in order to meet the required objectives. Consultation with Land Owners Technical representatives has demonstrated that riparian storage targets can be met and that the riparian storage will be defined as part of the Block Plan EIRs to meet existing values. Table 2.6 Comparison of Watercourse Riparian Storage (m 3 ) Existing Land Use Creek Location 100 Yr Regional Storm East Huttonville Fletcher s North of CNR 195, ,170 North of Wanless 19,520 24,530 Central Western Corridor Central Eastern Corridor Eastern Corridor Erosion Control The East Huttonville Creek erosion control assessment has been conducted based on a comparison of durations of flow rates at or above the critical flows for the existing versus future land use conditions at the respective erosion nodes. For the LID Scenario, each catchment includes lands draining to LID BMP s and areas that discharge directly to the stormwater management facility. As LID reduces the requirement for erosion control, each catchment has areas with a reduced volumetric rate. Areas not draining to LID BMP s require a higher erosion control volumetric rate. For each catchment draining to a stormwater management facility, erosion control volumes are calculated for the impervious areas draining to LID BMP s and the impervious areas not draining to LID BMP s, based upon the respective unitary volume requirements and corresponding impervious areas within the catchment. The total erosion control volume to be provided within the end-of-pipe facility is calculated as the sum of the erosion volume requirement for the impervious areas draining to the LID BMP and the erosion volume requirement for the impervious areas not draining to the LID BMP s. Fletcher s Creek has had two critical flows for erosion control established independently over the course of this study; m 3 /s (Case 1 CC1) and m 3 /s (Case 2 CC2) based on the Subwatershed Team assessment and CVC s assessment respectively (ref. Phase 1, Section 4.5). Consequently, the discharge rates for the erosion control component within the end-of-pipe facility depend upon the erosion threshold to be applied. While the erosion threshold determines the discharge rate from the erosion control component of the facility, it does not affect the requisite erosion control volume within the facility. Refinement of the critical flow to be used for the Fletcher s Creek erosion control assessment will be conducted at the EIR stage. Project Number:

31 Table 2.7. Erosion Control Storage Requirements Scenario Site/Node Storage (m 3 Critical Erosion Flow /imp. ha) Rate (m 3 /s/ha) F (Case 1) (Case 2) F (Case 1) (Case 2) Conventional F (Case 1) (Case 2) F (Case 1) (Case 2) HW HE F1 150 for Impervious Areas to LID BMP s (Case 1) 250 for Impervious Areas without LID BMP s (Case 2) F2 150 for Impervious Areas to LID BMP s (Case 1) 250 for Impervious Areas without LID BMP s (Case 2) SWM with LID 1. F3 150 for Impervious Areas to LID BMP s (Case 1) 250 for Impervious Areas without LID BMP s (Case 2) F4 150 for Impervious Areas to LID BMP s (Case 1) 250 for Impervious Areas without LID BMP s (Case 2) HW 200 for Impervious Areas to LID BMP s 325 for Impervious Areas without LID BMP s HE 150 for Impervious Areas to LID BMP s 200 for Impervious Areas without LID BMP s Storage values represent volumetric requirements for areas without and with LID BMP s. Water Budget The LID BMP capture rates defined as per Table 2.2 offer a significant benefit to erosion control volumetric requirements as noted in Table 2.7. It is recommended that there be some consideration for reducing the extended detention storage for Erosion Control based on the application of LID BMP s (to be refined as part of the EIR). The LID capture although reducing erosion control volumes, also benefits the overall water budget. As documented within the Phase 2 Impact Assessment, surface runoff would be marginally above existing volumes for East Huttonville Creek at Bovaird at 3% and a similar 2% increase for Fletcher s Creek at the limits of the Mount Pleasant development area. Water budgets to existing natural features will be assessed as part of the Block Plan EIR Stage to establish an appropriate hydroperiod with respect to wetland conservation, restoration and enhancement efforts. It has been proposed that roof drain collection systems for shallow features and both roof drain and foundation drain systems for deeper features be implemented to manage the overall ecological water budget for these features Surface Water Quality The stormwater quality management strategy has been established based on using LID infiltration best management practices and conventional stormwater management facilities that would provide Level 1 (Enhanced) quality control. The combination of LID and conventional stormwater quality management would in effect provide a level of water quality control above the current MOE Level 1 requirements for stormwater management. Stormwater management facility sizing has been provided within Table 2.8. Project Number:

32 CATCHMENT No. West Huttonville Creek Imp. Coverage (%) Table 2.8 Stormwater Management Facilities Characteristics Drainage Area (ha) Required Volume (m 3 ) Extended Permanent Detention Pool Water Erosion 1. Quality Huttonville Creek Flood Control Estimated Facility Area Requirements (ha) East Huttonville Creek Fletchers Creek With LID in-place 2. Based on MOE wet pond requirements Based on assessment of the generic infiltration LID BMPs and conventional stormwater quality management facilities, there would still be an increase in annual loadings for some of the Contaminants of Concern for proposed land use conditions compared to the existing land use. Retrofitting of existing stormwater management facilities, storm sewer outfalls and neighbourhoods using LID BMP s would work towards reducing the difference in annual loadings between future and existing land use conditions in order to address CVC s objective of a zero impact in annual loading. The undertook a Stormwater Retrofit Study in Project Number: Total

33 2005 which identified and prioritized stormwater retrofit sites as part of a City-wide strategy to reduce contaminant loadings and in-stream erosion within watercourses located within municipality. The will be updating this study in 2011, and is further committed to a sustainable funding source for implementation of retrofits to work towards a zero net loading objective (ref. Stormwater Management Facility Maintenance fund Section 3.5). As determined within Phase 2 Impact Assessment for the 3G Land Use, the difference in annual loadings in Zinc generally provides the most conservative parameter for water quality treatment based on the predicted increase in loadings. The would need to provide Enhanced (Level 1) treatment for the equivalent of 50 ha of residential area to compensate for additional loadings in Fletcher s Creek, and 175 ha of similar residential area to fully compensate for the impacts to the Huttonville Creek. Parameter TABLE 2.9 Equivalent Land Area (km 2 ) 1. Huttonville (H1 only) Fletcher s (F1, F2, F3, F4) TSS n/a n/a Cu 1.26 n/a E.Coli n/a n/a TKN Total P n/a n/a Zn Assumes 50% impervious Residential land use and Enhanced (Level 1) removal efficiencies. 2. Based on the 72% removal efficiency for Zinc (ref. Phase 2, Appendix E ). This is the MOE comprised relationship for removal of zinc in end-of-pipe systems, which was used as the critical parameter. In addition to the LID BMPs and conventional stormwater management facilities, broader based best management practices are available to assist in maintaining and potentially improving upon the annual contaminant loadings to both Huttonville Creek and Fletcher s Creek as provided in the following summary: Pollution Control/Prevention Practices Encourage and support contemporary measures at the Public and Private sectors. Reduced use of hazardous materials and improved practices (e.g. street sweeping, catch basin cleaning, salt management programs). Industrial/commercial property management [ref. CVC Pollution Prevention fact sheets including, (parking lot maintenance, snow and ice management, turf management and others)]. Stormwater Management System Maintenance Stormwater Management Facility maintenance is critical to overall functionality of the systems as designed; if not maintained, the systems will not meet the management standards for urban contaminants. Regular Routine and Capital Maintenance required. Need for sustainable funding to support maintenance. Project Number:

34 Construction Management Practices Loading, particularly of sediment, can be orders of magnitude higher during construction than under natural or stabilized conditions. Important to have a robust, integrated and well designed sediment management plan during construction (ref. Phase 3, Appendix A ). Need to apply and enforce guidance documented in Erosion and Sediment Guidelines for Urban Construction, 2006, Greater Golden Horseshoe Area Conservation Authorities. It is also known that currently used future urban land use loading rates are considered to be conservative as these have been developed based on historical water quality data. In recent years and in the imminent future many contemporary land use and human practices have reduced and/or are working towards reducing the use of hazardous materials (e.g. brake linings no longer proposed to use copper; pesticide residential use restrictions; salt management). These improvements over time will result in a reduction in net loading Thermal Impact Mitigation Various thermal impact mitigation techniques have been researched as part of the Subwatershed Study in an effort to develop a prioritized list of measures for implementation within the Mount Pleasant development area. A list of research materials is provided below, with other material provided within the Phase 3 Appendix E. [1] Ministry of the Environment. Stormwater Management Planning and Design Manual. Ontario. March (Ch 4) [2] Jones, M.P. Effect of Urban Stormwater BMPs on Runoff Temperature in Trout Sensitive Regions. North Carolina State University. Raleigh NC, 2008 (etd.pdf) [3] Jones, M. Hunt W. Urban Waterways Stormwater BMPs for Trout Waters. North Carolina State University (BMPsColdTemps2007.pdf) [4] Herb, Jenke, Mohseni, Stefan. Estimation of Runoff Temperatures and Heat Export from Different Land and Water Surfaces. St. Anthony Falls Laboratory. Minnesota (pr488.pdf) [5] Meritch Engineering. Preliminary Stormwater Management Report. Cambridge, ON. March c6475cdb7ee7/ds_devapprov_documents/z-10-07strmwtrpt1.pdf [6] Gamsby and Mannerow Ltd. Stormwater Management Final Design Report, Silvercreek Meadows Draft Plan of Vacant Land Condominium. Guelph, ON. January [7] Town of Ajax. Design Criteria Section C Stormwater Management and Storm Drainage. January Project Number:

35 Thermal impacts of Urban Development and Design Considerations, December 4, 200 Low Impact Development Stormwater Management Planning and Design Guide, Version 1, 2010, Credit Valley Conservation and Toronto and Region Conservation Authority. It is widely recognized that urbanization without appropriate BMP would result in negative impacts on receiving water bodies. Urban impervious surfaces gather thermal energy and thereby transfer heat to the storm runoff. The heated urban stormwater runoff enters aquatic systems, and potentially negatively impacts its resident organisms. Many of the organisms sensitive to temperature change. The dissolved oxygen content can become lowered, which can be of concern as many fish species require cool bodies of water and high oxygen content to survive [3]. Thermal pollution has always been recognized as an issue; however until recently there have been few practices and techniques that are employed to ensure that the stormwater entering natural water bodies are close to its natural temperature. Unfortunately, stormwater management facilities, such as open ponds, typically create an environment for resident water to gain additional thermal energy. The practice of thermal mitigation for stormwater management is generally in its preliminary stages, and there are limited studies, which offer clear and comprehensive information on the effectiveness of the respective techniques as follows: Facility Shading White and Green Roofs Facility Orientation LID BMP s Facility Bottom Draws Urban Forests Facility Cooling Trenches Floating Islands Others The information which follows is intended to guide and assist in the interpretation of a series of thermal impact mitigation practices currently considered to have some benefit in reducing the impacts caused by thermal enrichment of stormwater: Credit Valley Conservation has also been providing general practitioners in the field of Stormwater Management, data with respect to temperature impacts and mitigation through the on-going LID Conferences. To this end, Credit Valley Conservation is advocating the approach to Thermal mitigation on the basis of a series of zones, at which various thermal mitigation measures may be considered. Zone 1: Zone 2: Zone 3: Zone 4: Zone 5: At Source/conveyance (Up gradient) Stormwater Management Facility Inlet Structure Stormwater Management Facility Stormwater Management Facility Outlet Structure Riparian Corridor Techniques have been evaluated based on the zone approach cited above. Project Number:

36 Zone 1 Green and White Roofs These management approaches are known to reduce urban heating, however little evidence is available to suggest specific runoff temperature reductions. Zone 3 Stormwater Wet Ponds Stormwater wet ponds are similarly warmed by the sun. Since they are typically vegetated, it is necessary to use appropriate vegetation for maximum shade. If the pond vegetation can be improved upon, foliage shading can reduce the runoff temperature to up to 6 o C [4]. Zone 3 Stormwater Wetlands Stormwater wetlands are very effective at removing pollutants from runoff. However, they are shallow with a large amount of surface area that is exposed to solar thermal energy. To mitigate these impacts, it is important to incorporate broadleaf vegetation which would reduce the amount of direct sun exposure. The plants should have enough clearance from the water surface since the air in between will act as an insulator. Transpiration also helps to cool the effluent water [3]. If the wetlands are shaped long and narrow, they can also be more easily shaded by plantings [5]. Floating islands can also reduce direct sun exposure. Zone 4 Bottom Draw Outlet Design The surface water of a wetland is warmed not only from the sun, but also from the initial displacement of runoff at the onset of a storm event. Bottom draw outlets should be placed at 0.3 metres above the bottom (Assuming the pond is no deeper than 2.0 metres). To avoid clogging, a gravel envelope should surround the outlet [3]. A study conducted by M.P. Jones [2] determined the how effluent temperature is affected by the drain depth. The findings of the study indicated that lowering the drain depth from 0.48 m to 1.43 m resulted in an effluent temperature decrease of 4.3 % [2]. If the outlet is placed lower than 2 m, the pond should be aerated. However, aeration can cause further issues such as unwanted outflow turbidity [1]. Zone 4 Stormwater Management Facility Outlet Channels Outlet Channels from stormwater management facilities to watercourse channels and corridors should closely replicate natural channels in function and appearance. Their width to depth ratio should be close to 1:1, depending on the specific parameters. There should be a continuous band of woody riparian vegetation 3.0 m (+/-) wide along each side of the channel to provide shading and enhance channel stability. The channels should also be lined with clear stones to maintain the cooling contact time [7]. Project Number:

37 Zone 4 Cooling Trench Cooling trenches at stormwater management facility outlets can mitigate thermal impacts. Cool water trenches are stone trenches, typically located at the outlet of a stormwater management facility that use the lower temperature of the stone to reduce the discharge temperature. The Ministry of the Environment provides guidelines on trench sizing and configurations to maximize the thermal mitigation properties of cooling trenches. The Ministry of the Environment states that stones in the cooling trench should be (13 mm-25 mm diameter) as the water will contact more stone surface area [1]. Zones 1, 2, 3, 4 Infiltration/Filtration LID BMP s Infiltration/Filtration LID BMP s can be made up of three layers. The bottom is the under drain system, the middle is an engineered soil media with the top layer comprised of vegetation. Infiltration/Filtration LID BMP s are effective in reducing the heating of stored water since heat penetrates soil slower than water, reducing thermal spikes. The soil media layer should be up to 1.3 m in depth to minimize daily fluctuations and reduce runoff temperature spikes [3]. The vegetation cover provided in the top layer of the infiltration/filtration LID BMP s also provides thermal mitigation. Zone 1, 2, 3, 4 Low Impact Development (LID) LID BMP s are an overall practice that decreases the negative effects urbanization on runoff; some examples include bioretention facilities, green roofs, permeable pavement, increased topsoil depth, rain gardens, rain barrels and increased green landscaping. Public and private landowner participation in LID BMP s would provide some level of thermal mitigation, although quantification based on available research is not feasible. Zone 2, 3, 4 and Zone 5 Vegetation Vegetation shading is an effective way to provide thermal mitigation. In reference to the M. Jones study, 20% of the surface area is shaded, the effluent temperature difference is - 0.4%. If there is 40%, 60%, and 80% of the area shaded, its effluent temperature differences are -0.8%, -1.2 %, and -1.6% respectively [2]. Riparian corridor vegetation not only provides thermal mitigation of in-stream water temperatures, but also enhances channel stability and provides aquatic and terrestrial habitat benefits. Using the available research as summarized and the research on thermal impact modelling (ref. Appendix E ) the following provides a summary of the effectiveness of thermal mitigation practices: 1. Application of LID infiltration measures at source (noted to be effective by various organizations, but limited data exists to provide overall temperature mitigation) Project Number:

38 2. Vegetation canopy (urban forestry) over paved surfaces to reduce runoff temperatures, difference up to 3 o C +/- (source) 3. Use of concrete pipe versus plastic pipe (conveyance) reduces temperature impacts 4. Riparian planting can reduce stormwater management facility temperatures by up to 6 o C +/-, which dovetails with maximizing the length/width ratio (end-of-pipe) 5. Bottom draw outlets, can reduce temperature up to 6 o C +/- (end-of-pipe) 6. Cooling trenches, can in theory, reduce temperatures by up to 10 o C +/- (end-of-pipe) 7. Others, including but not limited to: facility orientation, floating islands, staged outlet structure, green roofs, white roofs Based on the effectiveness of the various thermal impact management practices cited and input as provided from the Steering Committee during the course of the Subwatershed Study, the follow provides the implementation priority of techniques to be considered for the Mount Pleasant development area: - LID infiltration BMP s - Urban terrestrial canopy (also NHS) - Facility shading (includes orientation and length/width ratio) - Facility cooling trenches - Facility bottom draws - Concrete Sewer System - Green & White roofs - Floating Islands - Other measures Temperature mitigation measures herein should be applied within the Mount Pleasant development area wherever possible. Pre-consultation with the and CVC would be required to determine the feasibility of applying each technique during the EIR stage Stream Morphology Input to Watercourse System Management Strategy Stream morphology is a key aspect that has been considered in developing the Watercourse Systems Management Strategy (ref. Section 2.2.8). As described in Phase 1, Section , based on field assessment, a geomorphic constraint ranking was established for each stream reach. Key details are recorded under the Channel Form element of the Evaluation, Classification and Management Table (ref. Phase 2, Appendix C ) compiled according to the Evaluation, Classification and Management of Headwater Drainage Features Interim Guidelines (TRCA/CVC, 2009). Stream management is to be approached on a reach basis as these units display relative homogeneity with respect to form and function. Key management practices, in terms of stream morphology, are recommended according to the geomorphic constraint rating, as described in Table Project Number:

39 Geomorphic Constraint Rating High Medium Table Management Strategy based on Geomorphic Constraint Rating Description of Stream Morphology These reaches have a defined channel (bed and banks) with well-developed channel morphology (i.e. pool-riffle) and provide both form and function. These are systems that could not be re-located and replicated in a post-development scenario. However, these reaches are also currently subject to pressures (e.g. agricultural practices) that could be mitigated through rehabilitation efforts. These reaches have a defined channel but may or may not have well-defined morphology. Many of reaches have undergone extensive alterations in the form of straightening and modification for agricultural drainage purposes. They are comparatively less sensitive to relocation and would benefit from rehabilitation. Management Strategy Maintain or improve the present condition of the stream in situ. Stream to remain in the form of an open channel but may be relocated. Rehabilitation should be considered including : Re-establishment of a more natural meandering planform Re-establishment of a functioning floodplain Re-establishment of riparian vegetation Provision of a low flow channel Low Ephemeral headwater swales that lack a defined channel but perform downstream functions related to both flow and sediment regime. Whilst these features may be eliminated, the downstream function and cumulative benefits of these features must be maintained, as measured against drainage density channel length targets. It should be noted that, within some reaches, the net rating is higher than the geomorphic constraint rating due to other key functions (e.g. flow, aquatic habitat, terrestrial). However, in no case is the net rating lower than the geomorphic rating. The management strategies described above are therefore fully incorporated, or better, within the overall Watercourse Management Strategy (Section 2.2.8) Potential Rehabilitation Management Practices The majority of the reaches within the study area have been previously modified, most notably as a result of agricultural practice and alterations made under the Drainage Act, and would benefit from rehabilitation. Rehabilitation measures that may be applied to medium rated reaches to improve geomorphological and habitat conditions may include: Re-establish a functioning floodplain: Creating a bankfull channel with better connectivity to a wider floodplain, or terrace, allows flows and fine sediment to overtop the banks during periods of high water levels. This excess water would then travel across the floodplain, dissipating energy across a much larger surface area. Vegetation would also decrease velocity, thus reducing erosion issues downstream Provide a low-flow channel: Creating a low-flow channel will provide storage and refugia for aquatic organisms during drought conditions as well as reducing the potential for sedimentation within the channel. Re-establish a natural meander planform: Using reference reaches as an indication of channel planform prior to agricultural influences; it is obvious that historical ditching Project Number:

40 and straightening has removed the natural meander planform of many reaches within the study area. This channelization effectively increases stream gradient and, consequently, the stream energy available to erode bed and banks. The restoration of a more natural meandering planform can help to re-establish more natural geomorphological processes and increase geomorphological diversity. Re-establish riparian vegetation: Re-establishing a healthy riparian vegetation community can help increase bank stability in addition to creating shading and improving fish and wildlife habitat. The provision of bank vegetation also provides a source of woody debris and organic matter for the stream, as well as providing a natural buffer to reduce fine sediment input from tilled agricultural fields. Such rehabilitation measures, excluding re-meandering, may also be used to enhance highrated reaches in-situ. More detailed consideration of appropriate rehabilitation measures will be undertaken as part of the Conceptual Fisheries Compensation Plan (CFCP) and Block Plan Environmental Implementation Reports (EIRs) Maintenance of Drainage Density and Channel Length As highlighted in the Phase 1 and Phase 2 reports, investigations have been undertaken to better understand the role of headwater swales since it is recognised that headwater swales (low-rated watercourses) play a functional role in supplying flow and sediment downstream. However, it is also noted that sediment supply / transport under existing conditions is influenced by human activities, including agricultural land management and potential inputs from road surface drainage, and therefore does not represent natural conditions. The creation of new swales where existing swales are to be eliminated is proposed as part of the watercourse management strategy to maintain drainage density channel length targets (Target NEW2). Several types of new swales have been identified and potential locations illustrated as part of the impact assessment and is summarised as part of the Watercourse Systems Management Strategy (Phase 2, Section ). Detailed consideration of how these new swales will be incorporated within the development plan will be undertaken as part of the CFCP and Block Plan EIRs Establishment of appropriate sediment regime Maintenance of drainage density and channel lengths will help maintain a stable bed sediment regime. The majority of potential channel locations that have been identified are connected to the NHS and do not flow through stormwater management facilities, and therefore could potentially contribute sediment downstream. Since the study area is underlain by similar surficial geology throughout, creation of new open swales as identified will also help maintain appropriate sediment sizing within natural limits. Refinement of the locations of swales will be undertaken within the Block Plan EIRs and CFCP. Channel design and subsequent channel management practices will be required to encourage the delivery of natural sediment supply. Streams in corridors should be designed such that Project Number:

41 natural erosion may occur in keeping with the nature of the channel, thereby replicating the natural potential to generate sediment for transport downstream. Naturalization of swales in urban areas should be encouraged where possible to facilitate natural sediment generation. It is however noted, that it is not necessarily desirable to replicate current sediment supply conditions in the headwaters since these are heavily impacted by agricultural practices, resulting in potential higher volumes of fine sediment conveyance than would occur under more natural conditions Maintenance of habitats dependent on coarse substrates Where the design of new channels or rehabilitation of existing channels incorporates creation or enhancement of riffle features, flushing flow thresholds should be applied in order to ensure the maintenance of pool-riffle morphology. Flushing flows are typically defined as those frequent flows, well below a two-year return period, which flush fines from the coarse matrix that comprises a riffle (Target NEW3). Riffle locations should be selected based on both geomorphological conditions and aquatic biology interests Channel design for low flows New channels should be designed to maintain a defined thalweg within the channel in order to help maintain conveyance of flow and sediment, and aquatic habitat connectivity, during low flow conditions (Target NEW4) Fisheries The aquatic biota that inhabit watercourses are determined by the current physical, chemical and biological characteristics of aquatic habitats, within biogeographic constraints. Biogeographic constraints refer to the fact that only species that have access to a site can potentially occupy it. Obligate aquatic animals that do not have a non-aquatic phase (i.e. fish, mussels, among others) can only disperse via water and, consequently, colonization or recolonization can only occur from habitats that are connected by water. Furthermore, downstream movement is more easily accomplished than upstream movement, which can be blocked by natural features such as waterfalls and analogous manmade features such as perched culverts. Many other faunal components, including most aquatic insects, have a terrestrial, flying, adult phase which allows wider dispersal. The relationships between fish, fish habitat, and the characteristics of the surrounding watershed, are fundamental and complex, and may be regarded as adhering to Commoner s first law of ecology - everything is connected to everything else (Commoner, 1971). As a consequence, changes to a watershed ranging in temporal and spatial scales from climate change to a footprint will have an effect on the aquatic ecosystem. The ability of an ecosystem to return to its previous state following a perturbation is often termed resilience, and resilience is influenced by a number of factors, including the type of perturbation, spatial and temporal scales of perturbation, and how these relate to past perturbations. Past perturbations are influential because they have already altered the system, and the current state is thus determined by the Project Number:

42 system s ability or inability to recover from these impacts. For example, the benthic invertebrate community in a watercourse that goes dry every year will be composed of species that have some means of coping with desiccation, which could be the ability to aestivate or the ability to recolonize when water reappears. Management objectives pertaining directly to biological components of aquatic ecosystems generally advocate either protecting the status quo, when it is considered to be a desirable condition or state, or changing the ecosystem to what is considered to be a more desirable condition or state. The state, and the success or failure of management, is usually defined in terms of the aquatic species or communities that are present, either now and/or in the future, and their abundance or their productivity. In the context of the Credit River Watershed Management Strategy Update (CVC, 2006),, the management objective is to Protect, restore or enhance native terrestrial and aquatic plant and animal species, community diversity and productivity. The aquatic biota targets adopted during this study are: Target 16a Healthy fish communities, appropriate for the habitats Target 16b Net gain in fish productive capacity Target New 13 No significant deterioration in Hilsenhoff Biotic Index Target 16c Species at Risk Protect Redside Dace populations From the aquatic ecology perspective, the success of the subwatershed plan and its implementation will be determined by how and to what degree these targets are achieved. This can only be determined by monitoring. This subwatershed study identifies targets pertaining to the aquatic biota and the features and functions that support aquatic biota and their habitat. The details of implementation will be provided in two additional documents, which are the Conceptual Fisheries Compensation Plan (CFCP) and the Environmental Implementation Report (EIR). To ensure a holistic and coordinated approach to the management of fish and fish habitat, and to facilitate and expedite the review of individual projects within the Block Plan areas that have the potential to affect fish habitat (e.g. transportation and servicing crossings of watercourses, channel lowerings, channel realignments, etc.), DFO representatives requested the preparation of a CFCP in the fall of 2009 during HFSWS workshops. The "Implementation Principles for the Subwatershed Study, November 24, 2009" (Implementation Principles), attached as Appendix F to the Secondary Plan, state A Comprehensive Fisheries Compensation Plan (CFCP) will be completed and submitted for approval concurrent with the preparation of Phase 3 of the SWS and the EIRs during the Block Plan process. The CFCP will be a free-standing document with a separate submission and approval process. These Implementation Principles were prepared and agreed upon by the, Ministry of Natural Resources (MNR), Credit Valley Conservation (CVC) and Mount Pleasant Landowners Group (MPLG). The CFCP is being prepared for the Mount Pleasant lands by the Mount Pleasant Landowners Group, and will be coordinated with the completion of the EIR. It will address predicted overall potential impacts, the mitigation of identified impacts, and the design of a compensation plan that will meet the DFO s requirement for no net loss of fish productive capacity. The terms of reference Project Number:

43 for the CFCP are being established through dialogue among DFO, OMNR, CVC, and the Mount Pleasant Landowners Group. The (City) requires that development within Secondary Plan areas proceed through the preparation of Community Block Plans. In order to receive approval of a Community Block Plan, an EIR must be prepared to the satisfaction of the in consultation with the Credit Valley Conservation Authority (CVC) and the Region of Peel (Region). The terms of reference for EIRs will be established through negotiations between the City of Brampton, CVC, OMNR and the Mount Pleasant Landowners Group. Administration of Ontario's Endangered Species Act is the responsibility of MNR and, because Redside Dace is an endangered species, certain activities associated with the development of the Mount Pleasant lands will require authorization through ESA where impacts to the species or its habitat are unavoidable. A Letter of Advice or Section 17(2) (c) permit may be required for development related activities that could impact the habitat of the species. Both the CFCP and the EIR need to address design and mitigation measures for the protection and/or recovery of Redside Dace and its habitat. The participation of MNR in both the CFCP and EIR processes provides the opportunities for consultation, and it is expected that these documents will form the basis for future review and permit documentation under the Endangered Species Act. ESA permit applications will be a separate submission and review process. The key legislation supporting these aquatic biota targets are the federal Fisheries Act, and the provincial Endangered Species Act. Various policies and guidelines provide additional direction, with varying degrees of specificity. In addition to the above, approval will be required from the CVC under the Conservation Authorities Act, Ontario Regulation 160/06.The most relevant legislation, policies and guidelines are reviewed below. The Fisheries Act The most encompassing legislation addressing aquatic habitat and fisheries is the Federal Fisheries Act. The Fisheries Act states no person shall carry on any work or undertaking that results in the harmful alteration, disruption or destruction of fish habitat (Section 35(1)) unless authorized by the Minister of Fisheries and Oceans, or under regulations made by the Governor in Council under this Act (Section 35(2)). As well, no person shall deposit or permit the deposit of any deleterious substance into water frequented by fish (Section 36(3)). The Fisheries Act defines fish as: parts of fish; shellfish, crustaceans, marine animals and any parts of shellfish, crustaceans or marine animals, and eggs, sperm, spawn, larvae, spat and juvenile stages of fish, shellfish, crustaceans and marine animals. The Fisheries Act defines fish habitat as: spawning grounds and nursery, rearing, food supply and migration areas on which fish depend directly or indirectly in order to carry out their life processes. Project Number:

44 The Policy for the Management of Fish Habitat (DFO, 1986) outlines various goals and objectives to strive towards in the management of fish habitat in Canada, as well as several strategies that are identified for implementation to either maintain, or improve, the productive capacity of fish habitat in Canadian waters. The policy also outlines general guidelines for the review of projects with the potential to affect fish habitat under the Federal Fisheries Act and its intention to protect Canada s fisheries resources. The Policy Objective is described as follows: increase the natural productive capacity of habitats for the nation s fisheries resources, to benefit present and future generations. The guiding principle behind the policy is no net loss of productive capacity of habitats. Within the Policy, three goals are identified: 1. Fish Habitat Conservation described as, maintain the current productive capacity of fish habitats supporting Canada s fisheries resources, such that fish suitable for human consumption may be produced ; 2. Fish Habitat Restoration described as, rehabilitate the productive capacity of fish habitats in selected areas where economic or social benefits can be achieved through the fisheries resource ; and, 3. Fish Habitat Development described as, improve and create fish habitats in selected areas where the production of fisheries resources can be increased for the social or economic benefit of Canadians. Any assessment of a fishery resource and the constraints that the presence of a fishery resource has upon development activity, must frame the assessment within the federal and provincial legislation designed to protect the fishery resource and species at risk. Federal protection of all fish habitat is provided under the Fisheries Act. Federal protection for species at risk is provided under the Species At Risk Act, for species listed in Schedule 1 of the Act. Provincial protection of species at risk is provided under the Ontario Endangered Species Act (2007). The Fisheries Act states no person shall carry on any work or undertaking that results in the harmful alteration, disruption or destruction of fish habitat (Section 35(1)) unless authorized by the Minister of Fisheries and Oceans, or under regulations made by the Governor in Council under this Act (Section 35(2)). As well, no person shall deposit or permit the deposit of any deleterious substance into water frequented by fish (Section 36(3)). Stemming from the Fisheries Act, the Department of Fisheries and Oceans (1986) Policy for the Management of Fish Habitat has the objective of creating a net gain of habitat for Canada s Fisheries resources. The guiding principle to realize this end is no net loss which requires that if the productive capacity of a fish habitat is reduced, then a compensating increase in fish production must be made to occur. The hierarchy of preferences for applying this principle to development, or other activities, is as follows: 1. Maintain, without disruption, the natural productive capacity of fish habitats through relocation, redesign or mitigation. 2. If the former proves impossible or impractical, then compensation by either creating new habitat, or by increasing the productive capacity of existing habitat, will be considered. It Project Number:

45 should be noted, however, that compensation may not be acceptable in some cases where the habitats in question are deemed especially important or sensitive. It should also be noted that an Authorization under the Fisheries Act triggers the Canadian Environmental Assessment Act, so that screening under this Act also becomes necessary. Administration of the policy at the local level has been delegated to Credit Valley Conservation (CVC) through a Level 2 agreement with DFO. Typically, CVC reviews the implications of the policy in conjunction with applications under Ontario Regulation 160/06, as well as through subdivision approvals, Environmental Assessments and other relevant processes. CVC s responsibilities include determination of whether or not potential habitat impacts can be mitigated to an acceptable level. If it is deemed that impacts cannot be mitigated, and the proposal involves compensation, applications to the Minister of Fisheries for approval of the relevant habitat impacts must be made, in conjunction with an acceptable plan for compensation of the proposed habitat impact/loss. The development of the Mount Pleasant area will involve the modification of fish habitat, including the lowering and relocation of seasonal fish habitat, and modification, including elimination, of headwater drainage features that do not directly support fish, but do influence downstream habitats that contain fish. Consequently, the proposed works will constitute a harmful alteration, disruption or destruction of fish habitat, commonly referred to as a HADD, and fish habitat compensation will be required. Compensation is defined in the Policy for the Management of Fish Habitat (DFO, 1986) as: "The replacement of natural habitat, increase in the productivity of existing habitat, or maintenance of fish production by artificial means in circumstances dictated by social and economic conditions, where mitigation techniques and other measures are not adequate to maintain habitats for Canada s fisheries resources." The Practitioners Guide to Habitat Compensation for DFO Habitat Management Staff (the practitioners guide) ( index-eng.asp accessed November 22, 2010) builds on the principle and concepts outlined in the Policy for the Management of Fish Habitat (DFO, 1986). The guide states that when compensation is required to achieve no net loss of productive capacity, the Hierarchy of Compensation Options should be followed such that: 1. Create or increase the productive capacity of like-for-like habitat in the same ecological unit; 2. Create or increase the productive capacity of unlike habitat in the same ecological unit; 3. Create or increase the productive capacity of habitat in a different ecological unit; 4. As a last resort, use artificial production techniques to maintain a stock of fish, deferred compensation or restoration of chemically contaminated sites. Ecological unit is defined as: Populations of organisms considered together with their physical environment and the interacting processes amongst them. Project Number:

46 The practitioners guide also states Where they exist, local fisheries management plans should also be used to help determine appropriate compensation options. The following descriptions of Compensation Options 1 through 3, below, are provided in the practitioners guide. Compensation Option 4, artificial production, is not considered relevant to the Mount Pleasant Development Area. Option 1 is categorised as like-for-like compensation, consistent with previous policy direction. It is favoured because it is assumed that it has the greatest likelihood of ensuring that the habitat enhanced or created will meet the objective of No Net Loss. Like-for-like compensation should aim to create or enhance habitat that has the same natural integrity, structure, and function of the habitat that was adversely affected. It is preferable to complete works on site before moving off-site. Option 2 is also consistent with previous policy direction. Creating or increasing the productive capacity of unlike habitat involves compensating for one type of fish habitat with habitat of a different type. This approach often means there is less assurance that a No Net Loss has been achieved. It is preferable to complete works on site before moving off-site. Option 3 involves the creation or increase of productive capacity in a different ecological unit. This option may compromise biodiversity objectives since the HADD will affect one distinct population while the compensation will provide benefits to different species. For example, a rocky shoreline used by bass and other panfish may be replaced with a sloping vegetated shoreline to be used for pike spawning. Again, it is always preferable to complete work on site before moving off-site. The practitioners guide also describes how all three Compensation Options may be employed in some projects. It is preferable to complete compensation at the higher levels before moving down the Hierarchy of Compensation Options. Only those residual compensation requirements that have not been satisfied should be completed under the next descending level. In many cases, the final compensation plan could include elements at more than one level, with some like-for like habitat and some unlike habitat creation. The ecological value of the existing habitat must be considered before moving down the Hierarchy of Compensation Options. In some situations it may not be possible to accept anything other than Option 1 (like for like) if the importance of the habitat being compensated for is too great. Additional guidance is provided with respect to circumstances when the hierarchy might not be followed. While the Hierarchy of Compensation Options should normally be followed, there are circumstances under which exceptions may be required. These involve situations where sitespecific issues are well understood and may include circumstances where limitations to productive capacity are known, and local management plans containing clear objectives for the fishery may have been prepared. Available information should support the effectiveness of an Project Number:

47 alternative compensation approach to achieve both no NNL and ecological objectives. This information could be used to justify moving down the hierarchy. For example, a portion of wetland feeding habitat supporting minnow species will be destroyed. However, according to documentation in the local fisheries management plan, this type of habitat is in reasonably abundant supply. In consideration of the fisheries plan objectives, a preferred compensation option might therefore be to enhance a nearby gravel spawning habitat, since it is known to be in limited supply for another species. This would mean justifiably moving from Option 1 to Option 3 on the hierarchy. In other situations, moving down the hierarchy may present a better opportunity for maximising the amount of habitat gained, particularly where there are known limitations (or bottlenecks). Allowances can be made for these situations, at the discretion of DFO. As indicated previously, because the development of the Mount Pleasant Community is expected to result in a HADD, DFO has been engaged in the planning process, and requested that a Conceptual Fisheries Compensation Plan (CFCP) be prepared for the Mount Pleasant study area. The preparation of the CFCP is being undertaken by the Mount Pleasant Landowners Group. Management of Redside Dace Habitat The only at-risk aquatic species known to occur in either Fletcher s Creek or Huttonville Creek is Redside Dace, and it is present in both, although it is not found within the Mount Pleasant study area in Fletcher s Creek. The Committee on the Status of Species at Risk in Ontario (COSSARO) originally assessed the Redside Dace as threatened in The species was uplisted to endangered in 2009 under Ontario s Endangered Species Act, 2007 (ESA 2007). Redside Dace was assessed as endangered in Canada by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) in April of It is currently listed as Schedule 3, special concern under the federal Species at Risk Act and Schedule 1 provisions of that act do not apply ( November 23, 2010). The Conservation Authorities Act Under the Conservation Authorities Act, CVC administers Ontario Regulation 160/06: Regulation of Development, Interference with Wetlands and Alterations to Shorelines and Watercourses. Through this regulation, the CVC has the ability to prohibit, regulate or require the permission of the authority for straightening, changing, diverting or interfering in any way with the existing channel of a river, creek, stream, or watercourse or for changing or interfering in any way with a wetland. The CVC may also prohibit, regulate or require the permission of the authority for development in a regulated area, if in the opinion of the authority, the control of flooding, erosion, dynamic beaches or pollution or the conservation of land may be affected by the development. The Credit River Fisheries Management Plan (MNR and CVC, 2002) and the Evaluation, Classification and Management of Headwater Drainage Features: Interim Guidelines (ref. CVC Project Number:

48 and TRCA, March 2009), both provide direction with respect to the management of fish habitat, and are discussed briefly below. Credit River Fisheries Management Plan The Credit River Fisheries Management Plan (CRFMP) was considered during the earlier phases of this study, including during the development of management targets. The CRFMP provides guidance with respect to the fish species that management actions should be targeted towards, the width of riparian buffers, and the timing for instream works, based on the fish communities that are present, or that it is desired be present, in the development area and downstream from the development area. Two fish communities mixed cool/warmwater and small warmwater are indicated by the CRFMP to be present in the Mount Pleasant study area. The descriptions of these fish communities in the CRFMP, with references to specific watercourses that are outside of the study area removed, are as follows: Mixed Cool / Warmwater Utilized by migratory trout and salmon in lower reaches of watershed including Fletcher s Creek reproduction is suspected but the relatively cooler waters to the main river can provide important refuge habitat for these young migratory species. Normally species associated with groundwater discharge headwater wetland areas such as central mudminnow and northern redbelly dace are common. However, these species are absent below the Niagara Escarpment in the Credit watershed. The redside dace should also be best associated with Cool \ Warmwater habitats but has also been reported in other stream types. Both Cool \ Warmwater and Small Warmwater streams have intermittent headwaters that certain species will utilize on a seasonal basis. Small Warmwater The most dominant species found include creek chub and blacknose dace. These species are also found in other stream types and best utilize intermittent reaches along with brook stickleback. Other species tolerant of warm temperatures and lower dissolved oxygen include bluntnose and fathead minnows. White sucker is also often common. A greater diversity of minnows, some habitat specialists and water quality sensitive species may also be present, especially where access to larger Mixed or Warmwater streams are available. Most typical of clay till plains with few silt/sand/gravel components such as Fletchers Creek. Two fish species identified as being members of the cool/warmwater fish community, redside dace and northern redbelly dace, have been captured in Huttonville Creek in the Mount Pleasant study area. Based on data compiled by M. Heaton, Ministry of Natural Resources, observation of one redside dace has occurred on one occasion in the Huttonville Creek downstream from the confluence of the east and west branches and upstream from Bovaird Drive. An observation of one redside dace has also occurred on one occasion in West Project Number:

49 Huttonville Creek at Mississauga Road. Both of these occasions have been post-1989 (M. Heaton, Presentation to the Natural Channel Design Conference, September 2010). This species was also reported from just south of Bovaird Drive once prior to 1989, and has been captured further downstream in the watershed on several occasions. Northern redbelly dace have been captured in East Huttonville Creek as far upstream as just north of the CNR, but the catches were dominated by creek chub and blacknose dace. Northern redbelly dace have also been captured in a pond further upstream within the City Park, but the pond is connected to the creek only by an overflow pipe. Based on the fish species present, and their relative abundance, and the descriptions of the cool/warmwater and small warmwater communities in the CRFMP, there is some ambiguity regarding the fish community that exists in East Huttonville Creek. It is recommended that the fish community be designated warm/coolwater upstream to the CNR crossing, which is the upstream limit of the redside dace occupied habitat designated by OMNR. Based on the dominance of creek chub and blacknose dace, and the presence of brook stickleback, at both of the locations where northern redbelly dace were captured upstream from the CNR, it is recommended that the fish community upstream from the CNR be considered small warmwater. The reaches of Fletcher s Creek that lie within the Mount Pleasant study area support a warmwater fish community. Redside dace, however, are present further downstream, and occupied habitat has been identified. Timing Windows and Riparian Buffers Timing windows refer to the time period when in-stream works (to bankfull), are allowed, with the required permits from MNR, CVC and DFO and municipalities (OMNR and CVC, 2002). Timing windows help to protect sensitive fish embryos and larvae, which are considered particularly sensitive to the effects of increased suspended sediment or bedload. Vegetated riparian buffers provide many ecological functions including: temperature regulation through shading; woody cover; natural food production (leaf litter and invertebrates); nutrient and sediment control; reduce pollution; erosion control; flood retention; and wildlife habitat/corridors (OMNR and CVC, 2002). Buffer widths will be applied where there is permanent or seasonal fish habitat on-site (OMNR and CVC, 2002). The Credit River Fisheries Management Plan (OMNR and CVC, 2002), provides guidance on the minimum riparian buffers for watercourses supporting different fish communities, and the Redside Dace Recovery Strategy (Redside Dace Recovery Team, 2010) provides guidance regarding the minimum riparian buffer widths for Redside Dace habitat (Ref Table 2.11). The time periods during which instream construction is permitted, and the recommended riparian buffer widths, are presented in Table Project Number:

50 Table In-Stream Timing Window and Riparian Buffer Widths Specified in the Credit River Fisheries Management Plan (OMNR and CVC, 2002), or, for Redside Dace Habitat, the Redside Dace Recovery Strategy (Redside Dace Recovery Team, 2010). Minimum Buffer Fish Community or This Width In-Stream Construction Width Greatest of Timing Window Meander Belt Width Justification Redside Dace Habitat To be determined (redside dace recovery strategy) or July 1 September 15 (CRFMP) meander belt width plus 30m Mixed Water Cool/Warm June 15 March 31 30m Protection of redside dace spawning Protection of spring spawning species only Mixed Water Cool/Warm that drain into coldwater June 15 September 15 30m Draining into coldwater; fall spawning Small Warmwater draining into large warmwater or cool/warmwater July 1 March 31 15m Protection of large warmwater top predators Management of Headwater Drainage Features The watercourses and drainage features within the subwatershed study area were evaluated with respect to the criteria provided in the document Evaluation, Classification and Management of Headwater Drainage Features: Interim Guidelines (ref. CVC and TRCA, March 2007), during the characterization phase. These guidelines, which were revised in 2009 (ref. CVC and TRCA, March 2009), provide a hierarchy of management recommendations/strategies for each class of headwater drainage feature, based on their function. 1. Protection (High Constraint) Permanent Fish Habitat, Critical Habitat and Species at Risk (SAR). Protection 1 permanent, critical fish habitat or habitat associated with species at risk. Generally associated with permanent groundwater discharge or wetland storage either habitat and/or flow source characteristics may be difficult to replicate or maintain. Preserve the existing drainage feature and groundwater discharge or wetland in-situ, particularly if species at risk are present; Maintain external drainage; Incorporation of shallow groundwater and base flow protection techniques such as infiltration treatment; Use natural channel design techniques or wetland design to restore and enhance existing habitat features, if necessary; realignment not generally permitted; Drainage feature must connect to downstream watercourse/habitat; Stormwater management (e.g. extended detention outfalls) are to be designed and located to avoid and/or minimize impacts (i.e. sediment, temperature) to fish habitat; Examine need to incorporate groundwater flows through infiltration measures (i.e. third pipes, etc.) to ensure no net loss and potential gain. Project Number:

51 Protection 2 permanent fish habitat generally with permanent standing surface water associated with a wetland and/or pond flows. Preference is to maintain existing surface water source; Maintain external drainage or if catchment drainage has been previously removed due to diversion of stormwater management flows, restore lost functions through enhanced lot level controls (i.e. restore original catchment using clean roof drainage) as necessary; Replicate on-site surface water sources including wetland creation and incorporating extended detention outlets, if necessary; Use natural channel design techniques to replace and enhance existing habitat features only if features are easily replicated; Drainage feature must connect to downstream watercourse/habitat; Examine need to incorporate groundwater flows through infiltration measures (i.e. third pipes, etc.) to ensure no net loss and potential gain. 2. Conservation (Medium Constraint) Seasonal Fish Habitat. Conservation 1 seasonal fish habitat associated with seasonally high groundwater discharge or seasonally extended contributions from wetlands. Potential permanent refuge habitat may be provided by a storage feature. Maintain existing seasonal groundwater or wetland surface flows, If catchment drainage has been previously removed due to diversion of stormwater management flows, restore lost functions through enhanced lot level controls (i.e. restore original catchment using clean roof drainage), as feasible; Replicate on-site seasonal groundwater or surface flows using infiltration measures and/or wetland creation, if necessary; Maintain external flows, Use natural channel design techniques to replace existing habitat features to maintain overall fish productivity of the reach; Drainage feature must connect to downstream habitat. Conservation 2 seasonal fish habitat associated with intermittent surface flows. Replicate on-site surface flows; Maintain external flows; or if catchment drainage has been removed restore lost functions through enhanced lot level controls, as feasible; Use natural channel design techniques to replace existing habitat features to maintain overall fish productivity of the reach; Drainage feature must connect to downstream habitat. 3. Mitigation (Medium Constraint) Contributing Fish Habitat Mitigation 1 Complex contributing fish habitat: flows conveyed through natural vegetation communities that support complex, contributing fish habitat i.e. influences water quality, sediment, organic matter, food and nutrients to the downstream habitat. Project Number:

52 Replicate functions through enhanced lot level conveyance measures, such as wellvegetated swales (herbaceous, shrub and tree material) to mimic online wet vegetation pockets, or replicate through constructed wetland features; Replicate on-site flow and outlet flows at the top end of system to maintain feature functions. If catchment drainage has been previously removed due to diversion of stormwater management flows, restore lost functions through enhanced lot level controls (i.e. restore original catchment using clean roof drainage); Feature form and flow that connects directly to downstream fish habitat (i.e. direct connection to other drainage features/watercourse or wetlands); Mitigation 2 Simple contributing fish habitat: flows that support simple contributing fish habitat, i.e. influences flow conveyance, attenuation and storage to downstream reaches. Replicate functions by lot level conveyance measures (e.g. vegetated swales) connected to the natural heritage system, as feasible and/or Low Impact Development (LID) stormwater options (refer to TRCA s Water Management Guidelines for details); Replicate on-site flows and outlet flows at the top end of vegetated swales, bioswales, etc. to maintain feature functions. 4. No Management Recommendation Required (Low Constraint) Not Fish Habitat. The pre-screened drainage feature has been field verified to confirm that no feature and/or functions associated with headwater drainage features are present generally characterized by evidence of cultivation, furrowing, presence of a seasonal crop, and lack of natural vegetation. 5. Recharge Protection Recharge Zone - No direct habitat or indirect habitat providing surface flow, sediment transport, or allochthonous contribution to downstream fish habitat. Maintain overall water balance by providing mitigation measures to infiltrate clean stormwater, unless the area qualifies as a Significant Recharge Area under the Source Water Protection Act. These areas will be subject to specific policies under their respective legislation. The subwatershed study categorized the watercourses and headwater drainage features based on the available information during Phase 1, and a quantification of the features that will be retained, modified, replaced or lost was conducted during the 3G evaluation. The management of watercourses and drainage features will be further refined during the preparation of the CFCP and confirmed through the EIR and detailed design. The Endangered Species Act 2007 (ESA) protects both individuals of a species and its habitat. Project Number:

53 Section 9 prohibits the harm of individuals. 9. (1) No person shall, (a) kill, harm, harass, capture or take a living member of a species that is listed on the Species at Risk in Ontario List as an extirpated, endangered or threatened species; Section 10 of the ESA prohibits damage or destruction of habitat of an endangered or threatened species. 10. (1) No person shall damage or destroy the habitat of, (a) a species that is listed on the Species at Risk in Ontario List as an endangered or threatened species; Section 17 lists the conditions under which the Minister may issue a permit to contravene sections 9 or section (1) The Minister may issue a permit to a person that, with respect to a species specified in the permit that is listed on the Species at Risk in Ontario List as an extirpated, endangered or threatened species, authorizes the person to engage in an activity specified in the permit that would otherwise be prohibited by section 9 or , c. 6, s. 17 (1). Limitation (2) The Minister may issue a permit under this section only if, (a) the Minister is of the opinion that the activity authorized by the permit is necessary for the protection of human health or safety; (b) the Minister is of the opinion that the main purpose of the activity authorized by the permit is to assist, and that the activity will assist, in the protection or recovery of the species specified in the permit; (c) the Minister is of the opinion that the main purpose of the activity authorized by the permit is not to assist in the protection or recovery of the species specified in the permit, but, (i) the Minister is of the opinion that an overall benefit to the species will be achieved within a reasonable time through requirements imposed by conditions of the permit, (ii) the Minister is of the opinion that reasonable alternatives have been considered, including alternatives that would not adversely affect the species, and the best alternative has been adopted, and (iii) the Minister is of the opinion that reasonable steps to minimize adverse effects on individual members of the species are required by conditions of the permit; or (d) the Minister is of the opinion that the main purpose of the activity authorized by the permit is not to assist in the protection or recovery of the species specified in the permit, but, (i) the Minister is of the opinion that the activity will result in a significant social or economic benefit to Ontario, Project Number:

54 (ii) the Minister has consulted with a person who is considered by the Minister to be an expert on the possible effects of the activity on the species and to be independent of the person who would be authorized by the permit to engage in the activity, (iii) the person consulted under sub-clause (ii) has submitted a written report to the Minister on the possible effects of the activity on the species, including the person s opinion on whether the activity will jeopardize the survival or recovery of the species in Ontario, (iv) the Minister is of the opinion that the activity will not jeopardize the survival or recovery of the species in Ontario, (v) the Minister is of the opinion that reasonable alternatives have been considered, including alternatives that would not adversely affect the species, and the best alternative has been adopted, (vi) the Minister is of the opinion that reasonable steps to minimize adverse effects on individual members of the species are required by conditions of the permit, and (vii) the Lieutenant Governor in Council has approved the issuance of the permit. 2007, c. 6, s. 17 (2). (3) Before issuing a permit under this section, the Minister shall consider any statement that has been published under subsection 11 (8) with respect to a recovery strategy for the species specified in the permit. 2007, c. 6, s. 17 (3). When a species is newly listed as endangered or threatened on the Species at Risk in Ontario (SARO) list, its habitat is also protected under the ESA The area of habitat protected is based on a general habitat definition found in the Act. The definition of general habitat is an area on which the species depends, directly or indirectly, to carry on its life processes, including life processes such as reproduction, rearing, hibernation, migration or feeding. This protection remains in place until a species-specific habitat regulation is created. Once a species-specific habitat regulation is created it replaces the general habitat described above. A recovery strategy, which provides advice to government, was published for redside dace in February, A draft government response statement was posted on the Environmental Registry in September, 2010, which summarizes the actions that the Government of Ontario intends to take in response to the strategy. A species specific habitat regulation for redside dace is being prepared and will be posted on the Environmental Registry on February 18, 2011 (M. Heaton, personal communication, November 1, 2010). The draft government response statement indicates that the government will develop urban development guidelines to provide guidance where there is an interest in developing urban areas within Redside Dace habitat, as protected under the Endangered Species. These guidelines will be posted on the Environmental Registry on February 18, 2011 (M. Heaton, personal communication, November 1, 2010). The Redside Dace Recovery Strategy (Redside Dace Recovery Team, 2010) recommends that all reaches (aquatic resource areas as defined by OMNR) currently occupied by Redside Dace be regulated as habitat under the ESA The Ministry of Natural Resources has identified both of the East and West Branches of Huttonville Creek from the CNR railway downstream as occupied habitat. The Redside Dace Recovery Strategy (Redside Dace Recovery Team, 2010) Project Number:

55 also recommends that groundwater discharge areas and wetlands that physically support the reaches occupied by Redside Dace also be regulated as habitat of the species. The Redside Dace Recovery Strategy (Redside Dace Recovery Team, 2010) states that redside dace habitat consists of two elements. The first element includes bankfull stream width within the aquatic resource area. The second element of habitat includes the meander belt width of the stream and associated riparian habitat that is a minimum of 30 metres from the meander belt (measured horizontally). Strategies for natural channel design and riparian buffer management that are specific to Redside Dace are described in the Redside Dace Recovery Strategy (Redside Dace Recovery Team, 2010) and supporting documents. These consider factors such as the provision of pools, which are a preferred habitat, and the management of riparian vegetation to produce terrestrial insects, which are a component of Redside Dace diet Terrestrial Management practices for the terrestrial components are focused on: Achieving individual terrestrial targets, Reflecting terrestrial opportunities identified in Table T4 in the Phase 2 Impact Assessment Report, the MOU principles and the SPNHS, and Having regard for relevant approved Background and Component Studies for the Mount Pleasant Secondary Plan. Terrestrial management strategies require close interdisciplinary collaboration on surface and groundwater quantity and quality, aquatic biology and fisheries habitat, and fluvial geomorphology. The identification of management practices is focused on the key components of the future NHS, i.e. existing upland woodlands and wetland spatial features, future corridors, restoration and enhancement areas, and buffers. Key integration issues include feature/habitat protection and management (including NHS implementation phasing), surface and groundwater interactions, aquatic habitat interdependencies, and interfaces with adjoining land uses, roads and trails Existing Natural Features and Attributes Natural features identified for protection in the SPNHS meet significant functional criteria as defined by the PPS and relevant Regional policies (significant woodlands, wetlands, significant wildlife habitat, linkage functions). The landowner vignettes (Schedule B to the Secondary Plan) provide conceptual guidance to the features, enhancement areas and spatial organization of corridors and stormwater facilities within the East Huttonville Creek system. Phase 1 of the Subwatershed Study summarized the features within terrestrial integration units, their documented significance, and relationships to surface water hydrology, groundwater, stream functions, and aquatic resources. Table in Phase 1 identified feature-specific opportunities related to the full range of natural heritage attributes, features and functions originally delineated by terrestrial ecologists from CVC, the Landowners consultants, and the Project Number:

56 Subwatershed Study team. Table T4 in Phase 2 (Appendix F ) summarized the status of these opportunities under the 2G/3G Plans. Fragmented habitats have been consolidated within the recommended SPNHS, and restoration areas are identified where enhancement or creation of natural cover is recommended. The SPNHS and the Schedule B vignettes incorporate diverse habitat elements, and consolidate functions related to feature shape and area, such as potential forest interior habitat and integration of successional elements. Reinforcement of core features will benefit key biota, augmented through provision of riparian corridors and naturalized habitat within stormwater management facilities. Feature Boundaries confirmation as per the SPNHS and Principles Existing upland and wetland features to be retained within the SPNHS are shown on Schedule A. Most outer boundaries of the feature complexes were field-staked in 2009 with participation of the NWBLG consultants, CVC and MNR staff. These boundaries form the basis of agreement on the Secondary Plan. Features or portions of features that have not been staked to date will require staking in consultation with City, MPLG, CVC and MNR staff. These staked limits form the basis of buffer determinations. Updated Feature Documentation and Community Mapping (including features outside of SPNHS) Feature mapping as presented in Phase 1 of the Subwatershed Study will be updated to consolidate the staked SPNHS, and the Principles, and site-specific truthing undertaken as part of the EIR. These updates affect implementation of management and enhancement initiatives in individual features, and assist in fine tuning the integration of such issues as: post-development surface and groundwater systems, and integrating trails and adjoining land uses to prevent impacts to key attributes and functions. EIR studies will focus on updating, consolidation and confirmation of data and analysis regarding the communities, biota and functions of all features. MPLG consultants have conducted additional field surveys from 2008 onward, adding to the original data documentation reported in Phase 1 of the Subwatershed Study. Each Block Plan EIR study process will ensure that consistent and current seasonal inventory data is collected for all features located within each Block Plan. The intent is to guide development and to provide direction to the City and CVC on future monitoring and management needs. Features not protected within the SPNHS should be screened as part of the EIR and/or Draft Plan studies, in accordance with such requirements as the City s Vegetation Assessment Guidelines and Woodlot Development Guidelines/Woodland Management Plan, respectively. The Vegetation Assessment Guidelines require the review of tableland features such as hedgerows and remnant cultural plantings, and the Woodland Management Plan to identify specific management measures for the feature and/or buffer. Opportunities may exist to integrate portions of the tableland vegetation features within SPNHS or development, or to salvage attributes for transfer to the SPNHS corridors, restoration areas or stormwater facilities. Project Number:

57 Previously undocumented biota and habitats, and any significant changes in status, will require refinement of the management practices within defined areas of the SPNHS. The EIR must reflect the most current information and practices for their management. Management practices for detailed consideration of hydrology and groundwater, swale compensation, trails and adjacent land uses as they pertain to the SPNHS are discussed under the relevant integration and adaptive management strategy sections that follow. Terrestrial System Opportunities Table T4 in the Phase 2 Impact Assessment summarizes guiding principles that were originally agreed to by the terrestrial biologists engaged in preparing the Terms of Reference for the Subwatershed Study (ref. Table 2 in Terms of Reference, 2006). The opportunities table was updated with the results of fieldwork in the Phase 1 reporting (ref. Table in Phase 1), and was used in the impact assessments for the POD and 2G Plans; the 2G opportunities have not changed with the advance of the 3G Plan. The SPNHS and Principles also identify terrestrial system opportunities and initiatives related to specific habitat restoration and enhancement. The EIR should update identified opportunities noted in Table T4 based on new inventory data and any other new information (e.g. species or feature status changes). Therefore the table information should be referenced in the EIR for the specific Block Plans, and revised with any relevant updates. This will serve as a baseline for EIR-based management initiatives, and for future monitoring. Cover Targets Targets have implications for initial planning, restoration and enhancement, and ongoing management of the SPNHS over many decades, and therefore the availability of City resources for future management need to be taken into account. As a general rule, it should be recognized that southern Ontario s climate and soils are conducive to the eventual establishment of forest cover, except on sites where soil conditions, ecosystem dynamics and microclimate prevent this process (e.g. bedrock bluffs, sand dunes, rocky barrens). The transition from open soil, to a closed woody canopy, normally occurs over a period of years after disturbance by cultivation is terminated. Heavy seed rain from nearby wooded areas or the presence of woody species that spread aggressively by vegetative means (aspen, sumac etc.) may shorten the transition period significantly. The quality of eventual forest cover is dependent on the species prevalent as seed rain, and the quality of soils (i.e. with intact versus highly altered soil structure and drainage). The long term maintenance of open meadow conditions requires either mowing at least every other year to suppress woody species growth, or cultivation (disking) every 3-5 years, which triggers a higher diversity of meadow species regeneration than mowing. Such interventions are key to ensuring that a blend of successional cover types of adequate size and linkage are retained in the landscape over time. Monitoring is required to identify the timing and extent of the management activities, but the techniques described here will ensure that quality habitats are maintained for the long term. Project Number:

58 The SPNHS Schedule B vignettes have identified some areas where open meadow could be maintained along the East Huttonville Creek corridor; other areas, such as the riparian corridor in the vicinity of redside dace habitat, must be maintained in specific open grassy cover in conformity with the Recovery Plan for that species. It is assumed that the City will manage cover along the corridors to cover targets and plant communities identified in the respective EIR s. These specifications should include target plant and wildlife species as well as potential and confirmed species at risk. The detailed design of specific natural and corridor areas should include prescriptions for management based on target biota and cover for each area. Except where otherwise prescribed for redside dace, the ultimate forest cover within riparian corridors and linkages should be in the 60-75% range to achieve a variety of environmental benefits. Reforestation of corridor nodes representing 25-30% of areas to be eventually forested, will trigger woody succession toward the end target. These targets are flexible and the EIR should provide the rationale for its finalized strategies. Open meadow cover should be massed in areas where meadow species are targeted, but wooded perimeters areas for these areas are desirable for structure and buffering. Invasive Species Invasive plant species have become a serious concern to ecologists since the 1980 s. The Phase 1 documentation has identified a number of invasive species of concern and determined their degree of invasion in each ELC unit. The following are key examples: Garlic mustard (Alliaria petiolata) invades wooded areas and is present in most of the woodlots in the Peel Plain. Its spread is exacerbated by the movement of topsoil, and human activities that disturb the soil profile. It is extremely difficult to eradicate (5+ years successive treatment with herbicide) and will ultimately require a more focused strategy, such as biological control. Common Reed Grass (Phragmites australis) is a salt tolerant species that has invaded our region along drainage courses and highways. It forms dense monocultures in wetlands and their periphery, reducing habitat structure and diversity for wildlife cover. Its robust root segments are readily moved when soils are disturbed, and it is also extremely difficult to eradicate. Reed Canary Grass (Phalaris arundinacea) is a nitrophilic (nitrogen-demanding) species which has spread along floodplains and other areas of imperfect to poor soil drainage. It spreads in response to nutrient concentration and sedimentation, and tends to replace diverse wetland or riparian cover with a dense monoculture. Giant Hogweed (Heracleum mantegazzianum) is a noxious species which has begun to spread in southern Ontario over the past decade. It typically forms patches in floodplain areas and is likely spreading from upstream sources as its seed are water-borne. The plant parts elicit extreme skin reactions in humans, which makes its removal a high priority. It was not detected in the Phase 1 studies but could become an issue in future years. There are many other invasive species in Peel Region, often spreading from plantings or through movement of soils; Havinga et. al. (2000) provided a comprehensive summary, and rating of each species in terms of the threats they pose to natural areas in southern Ontario. Project Number:

59 With respect to the planning purposes of the EIR, the presence of invasive species, their status within individual features was identified in the Phase I SWS and the EIR should determine potential management strategies. The information on these species and their management is changing rapidly through research, and therefore the most contemporary solutions should be brought forward at the time that designs and management plans are being prepared. Species at Risk The SPNHS has considered the reported or otherwise documented Species at Risk in the Mount Pleasant Secondary Plan study area, as well as locally to regionally significant wildlife species. Phases 1 and 2 also identified Significant Wildlife Habitats meeting the Region of Peel ROPA 21 criteria, and other features which support some of these species, which could be further enhanced and managed to help sustain these species in the local to regional landscape. Potential and confirmed species at risk and rare species should be a focus of EIR studies, to provide further information on their occurrence and status.* The SPNHS will connect to more extensive undeveloped landscapes in the Credit River valley and Greenbelt that can probably sustain some of these species. The guidance in the EIR, focused field studies during the EIR preparation, and detailed design consideration through individual site plans for development, should consider these species, and their specific needs in accordance with direction from MNR and available Recovery Strategies. The City should be provided with management prescriptions for the habitat where these species are found, and the development plans should include provision for habitat structures and safe road crossing details that can protect these species. (* The Block 51-1 and 51-2 studies were at an advanced state as this Phase 3 report was being prepared and these studies have already occurred; the recommendations for further updates are to guide subsequent Block Plans in the Subwatershed Study Area.) Terrestrial System Management after Development The final SPNHS contains existing natural features, habitat restoration areas, new habitat creation (especially along riparian corridors), and linkages (such as the TCPL corridor). The SPNHS will interface with trail systems, stormwater management facilities, and road crossings. The SPNHS must be completed in phases that serve to protect and manage existing resources, and to ensure that biodiversity and functions of the SPNHS are not lost during the land development process. Therefore the EIR must provide guidance to the City on the short to long term strategies to achieve the targeted NHS within each Block Plan area. These will take high level guidance from the SPNHS and Principles, and assure that specific targets are achieved at the feature level. Therefore a feature-specific strategy should be provided that addresses the desired short-, mid- and long-term objectives and targets for each feature, including those that are created or restored. These strategies should address relative vegetation community cover (ELC) for the targeted system, key biota targeted (for monitoring follow-up), and site-specific management issues and strategies (e.g. invasive species, hydrologic adaptive management, human impacts). The recommended status of the feature at time of assumption by the City, and the recommended future management actions, recommended timing and associated cost estimates will be provided as part of the EIR. Habitat cover targets and strategies, as well as phasing are discussed in more detail below. Project Number:

60 Riparian Corridors The conceptual location of all watercourses to be retained or relocated, and their proposed riparian corridors, are identified in the SPNHS (Schedule A). Some watercourses that currently extend through natural features will have flows diverted into new watercourses, and the abandoned reaches will be filled and restored (e.g. Item L on Schedule A). The recommended corridors for watercourses range in width from 45 to 100 m, including Regulatory Storm floodplain (and riparian storage), meander belt width (plus safety factor), side slopes (3:1 typical but variable slopes and treatments are desirable), and variable buffer/setbacks. The exceptions include East Huttonville Creek downstream of the TCPL corridor, where the regional floodplain (to be protected outside development) extends beyond the 100 m corridor, and the reaches (shown on Schedule A) where new corridors will be located adjacent to woodlots/wetlands, where a 5 m setback will apply on the feature side. Trails within Corridors A pedestrian trail may be placed within the corridor; in general trails should be placed along only one side of the corridor, and should not be placed in the vicinity of sensitive habitat features. Plant Salvage within Corridors The development of enhanced watercourse corridors presents an opportunity to recycle existing bio-diversity materials through salvage of seed banks and plant materials that would otherwise be lost during development. A discussion of landscaping standards and targets for riparian corridors is presented below. Corridor Habitat Enhancement Typical habitat enhancement components within corridors should include snags (dead trees anchored into the soil) to serve as perches for raptors and herons) and hibernacula (excavated pits located outside of floodplain, filled with large rocks and logs for snake overwintering). The corridors should integrate created terrestrial habitats elements outside the floodplain, including (where feasible) tableland wetland pockets fed with clean runoff from nearby rooftops and foundation drain collectors (discussed below under Restoration and Enhancement Areas) where feasible. Given the desire to carefully integrate these features, as well as stormwater management facilities, along the corridors (as per the SPNHS), some structural flexibility within the corridor footprint is desirable such that the overall setback is apportioned to provide adequate space for creation of pockets of upland cover, or off-line pools with wetland fringes (suitable for turtles and amphibians), trails, etc. In order to better accommodate such features, one of the side slopes could be steepened with localized use of armour stone, to optimize the space in the corridor and to provide habitat enhancement (i.e. sunning locations for reptiles, dens for smaller mammals). Redside Dace habitat management requires management strategies to establish and maintain specific cover along the channel, and to provide habitat for specific invertebrate groups that Project Number:

61 represent the food sources for this fish species. The approach should be guided by the Recovery Plan for this species, with input from MNR and DFO. Corridor Vegetation Strategies The following are key strategies to be addressed through the EIR and in detailed designs: Wetland creation within the floodplain as well as along the perimeter of the corridors; this is essential to meet wetland targets; Plantings in conformity with the valleyland landscaping standards; subject to consultation with City and CVC, alternative approaches will need to be considered in particular locations, e.g. meadows; Plantings to contribute riparian and wetland cover types that are uncommon in the LSA study area; these include thicket swamp, deciduous swamp, and coniferous / mixed swamp; Shading of the watercourse by regular planting of trees and shrubs, especially on the west and south sides of the floodplain; establishment of fast-growing, spreading and colonizing species such as native poplars, sumac, dogwoods and willows will be most effective; Integration of suitable cover to support Redside Dace recovery Over-seeding corridor areas with appropriate blends of riparian, wetland and upland species that are native to the Credit River watershed and Peel Plain; Significant food plants for wildlife (mast, berries etc.) should be included in all plantings; Application of salvaged riparian/wetland soil seed banks where feasible to new floodplains; this requires pre-identification of donor and recipient sites, and careful phasing; Large scale establishment of woody material by direct seeding or reforestation techniques is most cost effective for large corridor sections; focal area plantings where intensive screening, aesthetic and buffer cover is considered an immediate priority may be reliant on more formal landscape planting; Provision for monitoring, and management at regular intervals to adjust for identified problems (such as invasives); and Native plant species indigenous to the Peel Plain portion of the Credit River watershed should be utilized in all plantings, and to restore vegetation cover for wetlands, woodlands and meadows. Road Crossings and Wildlife Passage The SPNHS is intended to ensure that riparian corridors provide for safe passage, foraging and residency by terrestrial species. This necessitates that human uses within the corridors (i.e. trails, servicing access points) are carefully placed to minimize their impact on the functioning of the overall corridor, and that core habitats and supportive land uses will reinforce the corridor functions in key areas. Wetland and upland terrestrial habitat elements are recommended to be established along the corridors at regular intervals to enhance opportunities for seasonal use by species. Wetland creation locations and targets are discussed in more detail below. Project Number:

62 The Principles identify that road crossing designs will include considerations for wildlife passage, particular for small to medium sized terrestrial fauna, and for large fauna (i.e. deer) where appropriate. The future road crossings shown on the SPNHS are conceptual and subject to preliminary design as part of the EIR process and related infrastructure planning and design. Improved standards for road crossings of wildlife corridors are becoming more standardized; there is now a significant body of international research on the design or crossings, and monitoring results. Road crossing design for corridors encompasses human and wildlife safety, aquatic biology, stream morphology, hydrology and hydraulic input, in addition to terrestrial matters. The riparian channels specified in the SPNHS will consist of naturalized corridors at least 45 metres in width, usually aligned with natural features in the vicinity of crossings. Culverts will be utilized based on floodplain characteristics, with standards to be determined in EIR and CFCP and through detailed design. Finalized road widths and profiles will affect the opportunities for enhanced wildlife passage in each crossing location. Provision of wing walls and other elements to direct wildlife passage will be included in preliminary design requirements at the EIR stage, Crossings will require terrestrial benches to permit passage under a range of flow conditions, typically from low flow to bank-full. Accommodation of larger wildlife (i.e. white-tailed deer) is not optimal in most of Mount Pleasant due to the relatively undefined character of watercourse features through the landscape. The lower East Huttonville Creek valley provides more opportunities in this regard. Smaller terrestrial wildlife can be fully accommodated at all the crossings identified on the SPNHS, if terrestrial benches are provided and protective cover afforded with plantings and strategically placed rock and gravel. Road signage to warn of the potential presence of wildlife (particularly deer, waterfowl and turtles) at crossings of corridors is recommended based on monitoring. The interface of the SPNHS corridors at Mayfield and Wanless Roads will require careful consideration given the existence of existing residential uses that may remain or be transitioned to new development, and (in the case of Mayfield Rd.) the connections to future corridors in the Town of Caledon to the north. Trails will likely direct pedestrians to signalled intersections Restoration and Enhancement Areas Restoration and enhancement opportunities will encompass those identified in the Principles and SPNHS, Schedule B, terrestrial and wetland targets, Landscape Scale Analysis, and terrestrial opportunities identified in Phases 1 and 2 of the Subwatershed Study. Terrestrial Restoration Opportunities Schedule A summarizes proposed locations for habitat restoration, and Schedule B (landowner vignettes) show detailed concepts for restoration areas along the East Huttonville Creek. The EIR will specify the final recommended habitat cover types (based on ELC) and targets for area coverage and key habitat functions in accordance with the MOU as well as the Phase 2 Table T4 and the LSA Principles. The design team will incorporate consideration of any new feature data obtained during the biological surveys that will be required in support of the EIR. The intent of restoration and enhancement is to reinforce functions and attribute diversity such Project Number:

63 as: reinforce forest interior, add specialized wetland cover, improve habitat connectivity, increase natural vegetation community cover extent and diversity (including successional stages), reduce edge effects, and integrate a substantial amount of wetland restoration. Wetland restoration is recommended as a particular focus in order to achieve the overall wetland cover target of approximately 5.5% for the Secondary Plan area (target based on 3G SPNHS analysis summarized in Phase 2 Table 5.3.1; habitat areas are subject to refinement as more detailed plans are prepared). New wetlands that provide permanent and seasonal pools, marsh and swamp adjacent to upland habitats will reinforce the resilience of the SPNHS to support sensitive biota such as waterfowl, amphibians and reptiles. Native plant species indigenous to the Credit River watershed should be utilized in all restoration and buffer plantings, and to restore wetland cover; Localized restoration of agricultural lands and cultural communities may be required in some locations (such as in the vicinity of existing residential uses on Mayfield Road and Wanless Drive) to address past edge encroachments, reduce edge effects and to create a continuous, resilient and functional SPNHS. On-Line and Off-line Wetland Creation Based on the 3G Plan analysis, created floodplain wetlands in naturalized riparian corridors will contribute 4.1 % (approx.) in overall wetland cover, representing the floodplain zone. An additional 0.5 % (approx.) is recommended to be created as off-line wetlands within the corridors, and the wetland restoration in Area H (Integration mapping) will add 0.3% (approx.). Additional opportunities for created wetlands exist within the restoration areas identified on SPNHS; this should take the form of marsh, swamp or shallow ponds, given the flat topography and fine-textured soils in most of the identified restoration areas. These targets would total at least 5.5% wetland cover, a 400% increase from the existing mapped wetland cover. Corridor vegetation strategies are discussed above. (Note: the wetland area estimates are based on interpretation of conceptual plans such as the vignettes, and are subject to refinement as more detailed plans are prepared.) Created wetlands, and seasonal side/refuge pools in the SPNHS should be strategically integrated on-line within the riparian floodplains of enhanced corridors. They are also recommended off-line within the corridor setbacks and as part of supplementary habitat creation or restoration within otherwise unused void spaces that will result from the fitting of stormwater blocks, parks, and the corridors, around natural features. Spacing of diverse on-line and off-line wetland pool features at 100 to 250 m intervals along corridors will ensure that the needs of most amphibians can be met within the SPNHS area. Larger seasonal wetland/pool complexes will be concentrated in the restoration areas identified in the Schedule B concepts. Created wetland pools can range in size from tiny pit and mound pockets, to ha to 0.1 ha features in order to support a wide range of amphibians, turtles and waterfowl. On-line wetlands with seasonal pools usually consist of overflow areas that are recharged whenever bankfull events are exceeded. Pool depths ranging from 15 to 50 cm are recommended depending on available space, to ensure a mosaic of wetland cover from meadow marsh to critical zone pockets of open water with potential to sustain turtles as well as Project Number:

64 amphibians. The wetland design must be integrated with natural channel design to achieve the habitat coverage and range of wetland types. Wetlands should be located to avoid scouring by major flows. Diversification of structure should be provided with irregular feature edges, boulders, root wads, and snags. The water levels in created off-line wetland pools should be specifically designed to be sustained on a seasonal to permanent basis by clean surface runoff from the corridor, buffers and adjoining naturalized lands, supplemented with clean runoff from roof drains and foundation drain collectors where feasible. The ability to meet specific seasonal requirements of target wildlife (amphibians, waterfowl) must be demonstrated (ref. Section ). Target design species for wetlands and pools should be identified based on the available space and hydrologic opportunities at a given site. Pools for amphibian breeding must maintain water for a sufficient hydroperiod for the development of juvenile stages that are dependent on standing water, typically from early April until mid-june. Pools with standing water depths ranging from 10 to 130 cm deep will sustain a range of frog and turtle species. Deeper pools that retain water for longer periods or throughout the year will likely become populated with minnows and turtles which will predate amphibian eggs and tadpoles, however the provision of shallows, boulder structures and logs will reduce predation levels while providing basking areas. Turtles (i.e. Midland Painted Turtle and Snapping Turtle) will be attracted to deeper permanent pools with adequate basking opportunities and nearby nesting sites. For this reason the range of pool sizes provided, and their structural diversity, is important. Varying topography along the bottoms of the pools will provide an assortment of depths for the needs of different amphibian species that will be using the habitat. Placement of submerged and emergent boulders and logs will provide basking sites, and refuges from predators. Locating the seasonal pools close to existing natural features, such as woodlands and meadows will provide additional connectivity for species that require these habitats as part of their lifecycle. The quality and extent of the habitats in the vicinity (i.e. within m) of amphibian breeding pools is key to sustaining more sensitive species. Wherever feasible, seasonal pools should be located adjacent to summer foraging and overwintering habitat such as woodlands and shrubby areas. Pool habitats should not be created close to trails and active recreational uses. Section addresses the design of off-line wetland cover from the standpoint of their role in adaptive management of hydroperiods within natural features Buffers The Principles and SPNHS provide for buffers from terrestrial features, including 10 m from upland forest, and 20 m from wetlands. There is also a provision for minimum 5 m buffer between features and new channel corridors. Reinforcing Deterrent and Habitat Enrichment Functions of Buffers The 10 to 20 m buffers will represent the key areas to integrate hydrologic management and functional buffering of the natural features. (ref. Section 2.2.7). They will contain trails in some locations, and restrictive measures such as dense plantings of deterrent plant materials Project Number:

65 (i.e. thorny or wattle-forming), and fast-growing thicket-dominated wetland cover should be used to prevent pedestrian access into adjoining sensitive natural features. The buffers also offer opportunities to provide added native seed sources for tree and shrub species that have disappeared from many forested features due to past disturbance and high-grading. These can be drawn from ELC vegetation types that are more common in less disturbed sites on the Peel Plain. Conifers and swamp-adapted woody species are particularly important, as they can are well adapted to the fine-textures soils, and provide greater screening and natural food supply services. Buffer Roles in Adaptive Management The buffers provide an interface between development that can be utilized to monitor for conditions that may be deleterious to the natural features, including development of unauthorized and informal trails, inappropriate uses, and the introduction of invasive plant species. The buffers will also play a critical role in the adaptive management of the adjoining natural features, and may contain special grading, infiltration and conveyance features depending on location. The buffers have an important role in moderating the characteristics (quality and quantity) of water introduced for roof collection drains and foundation rain collectors. These roles are discussed further in Section Green Development Strategy Urban Tree Canopy Urban tree canopy cover has been identified as a key resource management opportunity to better manage air, water and energy in urban settings. The Region of Peel and are both undertaking studies to develop strategies for enhancement of urban canopy cover, which includes consideration of natural areas, but with a particular focus on planning, integrating and managing for greater tree cover within the urban areas of municipalities. The ongoing Peel Region Urban Forest Canopy Study will, upon adoption, likely require subwatershed studies to include urban forest canopy objectives. The Environmental Master Plan will establish canopy targets for the City. The City currently has street tree planting standards as well as planting standards for stormwater facilities, valleylands and parks. Stewardship programs that are already planting trees include the City's 10 year - $10 million Valleyland Naturalization program which may be extended subject to Council approval after There are ongoing community and school planting projects in cooperation with the Conservation Authorities and local community stakeholders. The Green Development strategy outlined in the NHS framework in Phase 1, considered that the built form of the future urban area could address landscape, energy and water management. This would require a carefully integrated approach to consideration of parks, trails, stormwater management facilities, and road corridors as greened elements, and intensive levels of tree planting to work toward aggressive urban canopy targets once the landscaping of new development areas matures. The application of Low Impact Development practices will likely have benefits for tree growth and canopy health. Project Number:

66 As well, the will be preparing Sustainable Community Design Guidelines in 2011, the next chapter of the Development Design Guidelines; and will partner with the City of Vaughan and the Town of Richmond Hill to test the proposed sustainability metrics of new developments, with particular emphasis on measureable decreases to development energy consumption and GHG emissions. The following objectives are intended to assist in the development of the Mount Pleasant Community Design Guidelines (CDG s), as well as guidelines for future Secondary Plans: 1. Design development to ensure that buildings and other uses capitalize on their location, and are sensitive to impacts on the surrounding natural systems; (i.e. compact built form, increased urban canopy, LID practices, increased landscaped cover relative to hard development, native vegetation use in landscaping, reduced irrigation and pesticide requirements, sustainable energy initiatives, etc.); 2. Consider naturalized elements with the park and trail system, on school properties, and along road and utility corridors; and, 3. Where feasible, develop schools and institutional uses with campus-like designs to reduce the impact of internal roads and parking areas, leaving space for low impact development and low maintenance landscaping. Intensified canopy cover requires the careful planning of building footprints, streetscapes, parking lots, and naturalized buffers and setbacks. Evaluation and integration of existing woody cover such as hedgerows and successional edges should be considered. The approaches to lighting (internal and external) in the vicinity of the SPNHS should be designed to minimize interference with the natural habitat cover in the vicinity. Window placement and coverings should be planned to minimize bird collisions. Extensive opportunities exist to increase functionality for wildlife and native plant species. The EIR should recognize all of the current city standards and requirements including street tree, open space and Parkland, stormwater management facility and valleyland planting standards, and incorporate approaches that reflect the general intent of establishing a strong urban canopy in conformity with the urban design guidelines for the Secondary Plan area. In the future, the City s ongoing Environmental Master Plan process will be examining opportunities to encourage private urban canopy stewardship and strengthening the urban tree canopy in the public realm through municipal programs Integration Watercourse Systems The management strategy for watercourses has been developed based on the net rating assigned to each reach through integrated assessment based on the Evaluation, Classification and Management of Headwater Drainage Feature: Interim Guidelines (TRCA/CVC, March 2009) (ref. Phase 2, Appendix C ). The net ratings take into account constraints Project Number:

67 associated with channel and groundwater flows, aquatic habitat (including Redside Dace habitat), terrestrial vegetation and functional linkages (including MNR-identified wetlands) and geomorphological form and function. A description of the management strategies associated with the overall net rating of streams is contained in Table High Rating (Red) Table Watercourse Management Strategies Based on Net Rating Net Rating Description Management Strategy These are reaches that could not be re-located Maintain or improve the present condition and replicated in a post-development scenario. of the stream in situ. However, these reaches are also currently subject to pressures (e.g. agricultural practices) that could be mitigated through rehabilitation efforts. Medium Rating (Blue) Low Rating (Green) Hydrology These reaches have undergone extensive alterations in the form of straightening and modification for agricultural drainage purposes. They are comparatively less sensitive to relocation and would benefit from rehabilitation. Ephemeral headwater swales that lack a defined channel but perform downstream functions related to both flow and sediment regime Stream to remain in the form of an open channel. Rehabilitation may include: Re-establishment of a more natural meandering planform Re-establishment of a functioning floodplain Re-establishment of riparian vegetation Provision of a low flow channel Unless otherwise noted in text. Whilst these features may be eliminated, the downstream function and cumulative benefits of these features must be maintained, as measured against drainage density targets. Hydrologic modelling using LID BMP s has shown that peak flows and flow durations have previously been maintained at key locations within the watercourse system. Durations of critical erosion flows have also been maintained for both East Huttonville Creek and Fletcher s Creek. The maintenance of the flow regime is critical to the watercourse system as fisheries habitat requires existing flows to be maintained as a minimum. Through flow monitoring and stormwater management adaptation, further improvements in flow duration may be possible on a localized scale. Hydrogeology The major groundwater discharge zone on Huttonville Creek within the study area downstream of the CNR line exists as a result of upward gradients combined with a permeable streambed connection. This connection appears to be a combination of local sand and gravel deposits and the connection to the bedrock. The physical attribute of the creek must be maintained. In areas where East Huttonville Creek, upstream of the CNR, is realigned and/or lowering intercepts the more permeable sand and gravel lenses or bedrock below the water table, increased groundwater discharge is likely. This can be beneficial to the aquatic habitat but may result in local water table lowering. This will also occur within the clay/silt till but to a lesser Project Number:

68 extent. In the process of the creek realignment if the existing portion is filled in or the outlet portion of the reach is closed than the local water table will rise to a new static position. Reach specific groundwater discharge is also managed through the maintenance of groundwater levels which provide the hydraulic gradient for the groundwater discharge. Maintaining the functionally significant groundwater levels and groundwater flow direction through various practices is described in Section Watercourses and Aquatic Regime Application of the management strategies above on a reach-basis is outlined in Table 2.13 and 2.14 and illustrated in Figure SM13. Reaches have been considered on an individual basis, but grouped in the context of proposed stream corridors. This helps to relate the stream management strategy to both existing reaches, which are to be maintained or enhanced, and new streams to be created. a) East Huttonville Creek Description Table Application of Watercourse Management Strategy on a Reach-Basis Reaches Net Rating Proposed Management Strategy Existing Length (km) East Huttonville Creek downstream of CNR Railway HV2, HV3, HV18, HV19c High Reaches to be retained or enhanced along existing alignment as part of the East Huttonville Creek stream corridor. Main creek HV19a, HV22 Medium Reaches to remain as open upstream of CNR (d/s), HV24 (u/s), watercourse as part of the East Railway HV25, HV26, Huttonville Creek stream corridor with HV29 potential for rehabilitation Creditview (City) HV22 (u/s), Medium Reach to be retained along existing Park HV24 (d/s) alignment through parkland with potential for rehabilitation. Tributaries HV23 Medium Reach to remain as open watercourse Other Tributaries HV19b, HV20, HV21, HV23b, HV27, HV28, unlabelled reaches Low with potential for rehabilitation. Reaches may be eliminated. However, where this in the case, creation of new swales will be required to ensure drainage density targets are met. Post- Development Length (km) Total Project Number:

69 b) Fletcher s Creek Description Creditview Road Channel Table Application of Watercourse Management Strategy on a Reach-Basis Reaches Net Rating Proposed Management Strategy F01, F02 Medium Due to loss of downstream connectivity, additional open channel to be maintained in Central East Channel instead (Reach F14), with potential for rehabilitation. West Channel F04 Medium Reach to remain as open watercourse, in current, realigned or lowered location, as part of West Channel stream corridor, with potential for rehabilitation. Central West Channel Central East Channel F07, F08, F10 Medium Reach to remain as open watercourse, in current, realigned or lowered location, as part of Central West Channel stream corridor with potential for rehabilitation. F12, F13, (F14 not included) Medium Reaches to remain as open watercourse, in current, realigned or lowered location, as part of Central East Channel stream corridor with potential for rehabilitation. East Channel F15, F17 Medium Reaches to remain as open watercourse, in current, realigned or lowered location, as part of East Channel stream corridor with potential for rehabilitation. McLaughlin Road Channel Other Tributaries F03, F05, F06, F09, F11, F14, F16, F19, F20, F21, unlabelled reaches F18, F22 Medium Reach F22 to remain as an open watercourse, in current, realigned or lowered location, as part of McLaughlin Road stream corridor with potential for rehabilitation. Low Reaches may be eliminated. However, where this is the case, creation of new swales will be required to ensure drainage density targets are met. Existing Length (km) Post- Development Length (km) Total An initial analysis has been undertaken as part of the Phase 2 Impact Assessment to identify where new swales could potentially be created (Phase 2, Section 3.3c) in order to estimate the post-development lengths. Potential locations for different types of swale identified within the post-development landscape, based on the 3G Land Use Plan, are illustrated in Phase 2, Figure SM10. Table 2.13 and Figure SM13 indicate that under the proposed watercourse management strategy drainage density targets will effectively be maintained within East Huttonville Creek. All High watercourses will remain in-situ and all Medium rated watercourses will remain as open channels, with opportunities for enhancement and rehabilitation along these reaches. It is noted that the section of the existing East Huttonville Creek to remain through Creditview Park will function differently post-development due to the diversion of flows through the new East Huttonville Creek. In recognition of this, this section has been identified as a separate category under Low-1 within the proposed channel type hierarchy (see Phase 2, Section ). Project Number:

70 Within Fletchers Creek, under the proposed watercourse management strategy, the majority of Medium rated watercourses will remain as open channels on the landscape, with potential for rehabilitation. The majority of these Medium rated reaches (with the exception of F15 and F22) are currently agricultural swales, as identified in the Phase 1 characterization process (ref: SM1 and Phase 2, Appendix C ). They are rated as Medium based predominantly on terrestrial vegetation and linkage functions rather than fisheries or channel form considerations. The proposed development will result in increased definition of the majority of these watercourses within stream corridors as part of the NHS. There is no planned replication of a stream corridor for Reaches F01 and F02. Both of these reaches are rated as low in terms of fisheries and geomorphological interests and are no longer connected to watercourses downstream. The length of Medium channel represented by these reaches is compensated for since Reach F14 is to remain as an open watercourse within the Central Eastern Channel though this reach has a Low net rating. There is currently no planned replication within a corridor for Reach F18. This reach was rated as Medium based on terrestrial ranking as a potential linkage to the natural systems north of Mayfield Road. Based on the Mount Pleasant SPNHS and proposed corridors within Mayfield West CEIS, Phase 2 (Town of Caledon), the connection to the north will occur along Reaches F17 and F22; this eliminates the need to maintain F18 for terrestrial linkage purposes. F18 is an ephemeral feature classified as simple contributing fish habitat and of low constraint in terms of channel form (ref: Phase 2, Appendix C ). The physical function of this reach is therefore replicable through incorporation of new swales in the development area. Further opportunities for incorporation of additional lengths of swale will need to be sought in Fletcher s Creek to reduce the estimated 7.95km net loss of channel length (ref: Table 2.14). Additional opportunities for creation of new swales which have not been included to date within the proposed watercourse management strategy are: New swales within NHS buffer perimeters, Swales within private property ownership (residential/employment), Low Impact Development Best Management Practices, and Overbank fish habitat outlets / backwaters connected to the stream network. The location of new swales should ideally be concentrated within those subcatchments of Fletcher s Creek identified in Phase 2, Appendix C4 as currently not meeting the minimum drainage density target. Fisheries The realignment of the East Huttonville Creek, north from the CNR to Mayfield Road, and the five Fletcher s Creek tributaries, from north of Wanless Drive to Mayfield Road, has been fundamental to create a linked natural heritage system. The lowering of the invert of these watercourses has been fundamental to the development and servicing of the Mount Pleasant Community. Project Number:

71 The newly constructed channels that replace or replicate existing channels will benefit from the use of natural channel design to improve the channels physical condition and ensure linkage with the flood plains. Benefits to fish habitat are expected to occur as a result of increased riparian corridor widths and increased proximity of watercourse corridors to some of the existing terrestrial features. The increased duration of flow or extended persistence of standing water, which are expected to occur as a result of stormwater management and, possibly, other infrastructure, is expected to increase the length of watercourses providing permanent fish habitat. A combination of end-of-pipe stormwater management and LID BMP s, combined with the integration of swales and overbank areas in and adjacent to the riparian corridors will manage flow quantity and quality to protect the integrity of downstream aquatic habitats. The habitat preferences/requirements of the headwater fish community (fathead minnow, brook stickleback) that is tolerant of low gradients and does not require coarse substrate for spawning, differ from those of the downstream fish community (creek chub, white sucker, redside dace) that do required coarse substrate for spawning, as well as preferring higher gradients. It is expected that the detailed designs that will be developed at the CFCP/EIR stage will favour the fish community that is most likely to occupy a reach, taking into account downstream impacts. Terrestrial System The watercourse corridors represent the most significant and extensive source of net gain to habitat cover and functions within the SPNHS. Key watercourse integration issues affecting the terrestrial components of the SPNHS include: Relationship of created habitats within corridors to fluvial and hydrological/hydraulic objectives, Consideration of specialized habitat needs (redside dace and other species), Effects of channel lowering and/or relocation on specific terrestrial features, Integration of road crossings (discussed above), Integration of trails along corridors (discussed above), Role of swales and LID in adaptive management of natural feature hydrology, and Effects of flow events (including the Regional Storm event) on habitats and biota. The recommended approaches for the creation of vegetation cover along the corridors, and road crossings, are discussed in earlier sections. It is anticipated that through the EIR process, the objectives related to stream functions, hydrology and hydraulics will be adapted in an integrated manner that balances potential benefits to site-specific realities. Terrestrial needs such as cover diversity and safe passage should be considered as an integrated part of the typical cross sections and profiles of the watercourse systems. Though interdisciplinary discussions (with landowner consultants, CVC and MNR), the implications of the Redside Dace Recovery Strategy will need to be addressed in the EIR, providing specific guidance for the detailed design of particular stream reaches. The maintenance and monitoring of these measures will also need to be addressed. Project Number:

72 Floodplain Connectivity Changes The SPNHS and Principles define committed future conditions, including the relocation of watercourses, elimination of some low constraint headwater drainage features, and containment of the Regional Storm event within stream corridors. As shown on Phase 1, Figure NSI-1 in Phase 1, although the majority of forest units contain some areas that fall within the existing Regional Storm floodplain, modelling of the existing system indicates that overbank events do not occur regularly in the pre-development setting. The existing channels represent outlets for sub-catchment units that at one time were probably more isolated and self-contained hydrologically, except under exceptional events. This implies that the future hydroperiods in natural features could be restored to more typical historic seasonal patterns that are beneficial and appropriate to individual units or specific wetland areas within the units. Modelling of the existing system indicates that overbank events do not occur regularly today. The EIR should confirm the relationship between natural features and the existing and future channels on a site specific basis, and identify any features that will require mitigative treatments such as catchment supplements, or microberms to impede storage loss, to manage seasonal hydroperiods. Swales and LID BMP s Swales will be common NHS infrastructure elements located in natural feature buffers, corridor setbacks, interfacing parks, and stormwater blocks. They will be key to providing surface water conveyance in the vicinity of natural features, and can be managed to optimize adaptation of the hydrologic regimes within natural features, either by tweaking with micro weirs to detain low flows for greater filtration benefit, or improving efficiency of flows to improve drainage efficiency where hydroperiods are identified to be excessive. It should be recognized that as restored natural cover matures, the systems typically retain more water. Therefore the compensation swales offer the opportunity to provide for adjustment over time, based on monitoring. LID such as bioswales may be integrated with the buffers, corridors, swales and stormwater blocks based on site-specific design consideration. These form a design tool to augment infiltration within appropriate habitat cover in specific areas. Extreme Flow Events The potential effect of extreme flow events on the integrity of the NHS and its biota has been identified as a concern. In general, it should be acknowledged that the channel flows associated with a major event will be accompanied by inundation within adjoining natural features, and flow concentration will be more limited in the headwater setting than further downstream. The channels will contain structures to manage Regional Storm flood control. More extensive floodplain coverage is present in the downstream reaches of Huttonville Creek. The SPNHS will provide relatively continuous upland habitat cover areas with unimpeded access between the watercourse corridor and adjoining habitats. This high level of feature flankage along the corridors will afford refugia during major events. Therefore it is not anticipated that major storm events will significantly impact the sustainability of biota within the SPNHS. Project Number:

73 Natural Heritage Systems Hydrology The Natural Heritage System includes the watercourse corridors and the linked woodland and wetland features. The hydrologic modelling has demonstrated that the flow regime and water budget has been maintained to the Natural Heritage System. The localized water budgets for the woodland and wetland features will be established within the EIR stage. Woodland and wetland features will receive clean runoff from rear yards, roof drains, and potentially foundation drain collectors. Flexibility in the design of the collection systems and monitoring will facilitate potential refinements to the woodland and wetland features. It is understood that the woodland and wetland features are primarily surface water fed, therefore based on the minimal 2 to 3% increase in runoff for both Huttonville Creek and Fletcher s Creek, Mount Pleasant Community, maintaining local water budgets to features should be feasible. Hydrogeology The groundwater balance is one component of the overall water balance needed to maintain the Natural Heritage System. Specific aspects related to creek reaches have been discussed previously. The overall water balance characterization is intended to provide an understanding of the typical surface water and groundwater levels, surface water and groundwater fluxes and evapotranspiration on a seasonal basis for the terrestrial features. The maintenance of the groundwater flow system/ groundwater balance and subsequent management practices linked to the terrestrial features must be discussed within the context of the expected functional significance of the abiotic/biotic linkage and the expected extent of quantification of the groundwater flow system parameters. It is the general understanding through this study that the terrestrial features are not groundwater discharge driven with respect to significant quantities of groundwater flux. Where hydraulic gradients are directed towards these features groundwater fluxes may be on the order 2% or less of the total water budget. It is expected that these features are groundwater recharge features and that the feature specific groundwater levels are maintained by overland flow and/or direct precipitation. Decreases in overall groundwater levels could potentially increase the recharge from these features or reduce the groundwater flux to these features where there are associated upward gradients. On a larger scale the current modelling shows that groundwater level changes associated with a large scale, development wide reduction in recharge can be addressed through LID management practices. General considerations for these practices have been previously discussed. The groundwater flow systems associated with these terrestrial features may be very local in nature (i.e. a relatively closed system with respect to 3 dimensional flow direction and fluxes Project Number:

74 Section Phase 1) and, as such, maintenance of groundwater levels within a buffer area may be sufficient by maintaining the existing overland flow to the buffer area, maintaining existing buffer topography for recharge (or creating additional hummocky topography within the buffer). A refinement of the extent of the groundwater connections to these features and the ecological significance would be carried out at the EIR stage. Discussions on the quantification of certain groundwater characteristics related to these features occurred within various Phase 1 and Phase 2 workshops. These discussions included the quantification of groundwater flux, water levels and soil saturation. The overriding issues relate to the level of quantification and the spatial and temporal variability of the factors driving groundwater flux, water levels and soil saturation. On very local scale any consideration for the expected level of quantification must take into account the following: The hydraulic conductivity used to calculate fluxes can vary by 2-3 orders of magnitude, Hydraulic gradients can vary over short time frames, can go from positive to negative and are 3 dimensional in nature, The tension saturated zone depends on the soil structure which is highly variable, Actual recharge which drives local, short term groundwater levels can depend on the amount and duration of event precipitation, canopy flow through, local overland flow (which can be highly variable due to microtopography), snow melt, frost depth, ET If the expected level of quantification is high (within 1%) for say groundwater flux to a terrestrial feature the amount of monitoring necessary (spatially and temporally) and the uncertainty in the parameters does not make the assessment practical. The sensitivity of the terrestrial feature to the groundwater linkage would direct the level of quantification and hence monitoring but the realistic limits due to uncertainty have to be considered. Realistically in the majority of cases we are dealing with a range of quantification or semi-quantification. From a management perspective the overall increase in terrestrial cover may increase recharge through the additional retention of overland flow, creation of macropores and a more permeable organic surface bed. Additionally the increase in ET may depress local water levels seasonally and the effect must be considered within the groundwater level monitoring program and overall post development impact assessment. Watercourses and Aquatic Regime Six stream corridors identified in the proposed 3G Land Use Plan are an integral part of the Natural Heritage System: Project Number:

75 East Huttonville Creek Fletcher Creek West Channel Central West Channel Central East Channel East Channel McLaughlin Road Channel A detailed analysis of how these stream corridors relate to existing reaches is contained in the previous section (Phase 3, Section ). Existing high constraint reaches will be retained and enhanced within the NHS (Huttonville Creek Reaches HV2, HV18 and HV19c). The remaining medium constraint reaches will remain as open channels within the NHS, with potential for rehabilitation (including realignment). Most of the Medium rated reaches in Fletcher Creek are currently agricultural swales rated as Medium based predominantly on terrestrial vegetation and linkage functions rather than fisheries or channel form considerations. The proposed development will result in increased definition of the majority of these watercourses within the stream corridors of the NHS. A number of swales will also be maintained within the NHS and new swales will be created within public lands and downstream of stormwater management facilities joining the NHS (ref: Phase 2, SM10). Additional swales will also be sought within NHS perimeter buffers in order to maintain drainage density targets. A section of the existing East Huttonville Creek will remain through Creditview Park but is not part of the NHS. This reach will function differently post-development due to the diversion of flows through the new East Huttonville Creek in the NHS. In recognition of this, the reach has been identified as a separate category under Low-1 within the proposed channel type hierarchy (see Phase 2, Section ). Fisheries The SPNHS has placed a significant focus on the protection of existing woodlands and wetlands within the Mount Pleasant Community, with the realigned watercourse corridors creating both aquatic and terrestrial linkages. East Huttonville Creek will be relocated along a course that will more closely resemble its historic location, prior to its realignment for agricultural drainage purposes. Requirements for wetland restoration have been identified by the MNR and CVC that will influence the management of some watercourse and/or headwater drainage feature reaches. Most of these reaches have been realigned or constructed to facilitate drainage for agricultural purposes, and now they provide contributing or seasonal fish habitat. The effect of wetland remediation and restoration on fish habitat will be dealt with on a case by case basis through the CFCP and EIRs, in a manner that ensures an overall net gain of fish productive capacity is achieved. Project Number:

76 The management of riparian vegetation within the East Huttonville Creek, downstream of the TCPL, and particularly downstream of the CNR (i.e. the occupied reach) is an important consideration given the significance of the riparian zone to Redside Dace. Terrestrial System This section examines rationale and strategies to monitor and address the water balances and potential change in hydrological conditions from a terrestrial biology standpoint. The most critical NHS management practices are surface and groundwater flux to existing, restored or created natural features. This includes consideration of functions and opportunities associated with tableland swales. Surface and Groundwater Regimes of Natural Features As a basic standard, an assessment of the need for water balance calculations for existing and proposed conditions are required where sub-catchments containing spatial integration units (as identified in Phase 1) extend into the area to be developed. The existing system characterization of relative groundwater and surface water components should reflect monitoring data for surface and groundwater in susceptible features (i.e. those within subcatchments that will contain development) to determine existing system responses to average precipitation patterns and seasonal patterns. The intent is to achieve an understanding of typical seasonal surface and groundwater levels, evapotranspiration responses, and water level fluctuations in the features.. Given the existing disturbed character of the landscape, this analysis may identify situations where non-normative water level fluctuations are presently occurring, or where moisture retention could be optimized through the restoration of hydroperiods that would have been present prior to stream and swale works which fragmented natural drainage patterns under past agricultural uses. Natural Wetlands - Pre-settlement Context Section in Phase 1 presented a summary of pre-settlement conditions, and Section in Phase 1 presented an integrated assessment of the primary natural hydrologic functions evident in this landscape. The understanding of these natural systems is also informed by sitespecific examples of clay and till plain features and their management in Brampton, Mississauga, Niagara Region and Toronto over three decades. In essence, the remnant natural features in the study area represent fairly typical Peel Plain wet forests where imperfectly to poorly drained soils predominate, sometimes including organic soil accumulations. The groundwater characterization has concluded that these are predominantly recharge groundwater systems, with very localized exceptions such as in the vicinity of City Park and just south of Mayfield Road, where upward discharge gradients may occur seasonally. However such upwellings are subtle, impeded by the heavy soils, masked by evapotranspiration effects and the dominating surface runoff effects, and therefore discharge is unlikely to significantly extend wetland hydroperiods. Project Number:

77 Based on available mapping evidence, defined watercourses were probably much more limited in extent historically in the Mount Pleasant study area. In the pre-settlement state, a range of hydrologic features would have existed, including: closed-catchment pools arising from post-glacial land-forming processes; micro-depressions formed (or expanded) by forest dynamics (i.e. pit and mound processes); virtually flat areas or very subtle slopes where slight surficial irregularities, surface roots and woody debris cumulatively enhance infiltration in wet periods; and riparian interfaces where channel floodplains would interface with the wet forest regimes. Under these conditions, horizontal flows are often apparent under spring freshet conditions, and then typically recede. The pattern of infiltration and cross-flow in the landscape therefore varies seasonally and under different conditions of soil saturation. In general, these soil and vegetation systems are very conservative of water quantity and quality, capturing and storing the majority of snowmelt and spring rainfall, then losing it, initially as attenuated runoff, then to evapotranspiration after leaf cover emerges. The associated wet forest vegetation represents a continuum from wetland to upland; there is seldom a discrete interface between wetland and non-wetland cover. This complicates the definition of wetland under the ELC and Ontario Wetland Evaluation Systems, and typically soil horizon colour indicators must be utilized rather than vegetation cover. The management implication is that the overall natural features must be treated in an integrated manner; adjustment of wetland hydrology will invariably affect the wettest, as well as better drained areas. The degree of seasonal saturation may vary over decades with localized development of organic soil pockets, and accumulation of woody debris which tends to cumulatively enhance surface and shallow groundwater storage over time. Existing Status and Anticipated Future Change Section in Phase 1 noted that the present distribution of woodland cover within the Subwatershed Study area and vicinity has been more or less static since the 1890 s. There were gradual adjustments to stream form and extent due to farming activities that intensified after WWII. Changes included relocation of existing watercourses, creation or deepening of swales, installation of field tiles, and excavation or enlargement of ponds for livestock use. The wet forests also underwent significant biological, structural and hydrologic change related to cycles of logging and selective tree species removal (i.e. rutting, repeated alteration of surface flows), desiccation due to edge disturbance, and year-to-year fluctuation of catchment inflows due to varying patterns of agricultural cropping and ploughing in the adjoining fields. Today the majority of the features are dominated by green ash, the most widespread and adapted ash species in North America. Green ash has a wide ecological distribution, conferred by its resistance to salt, flooding, drought and high alkalinity. More intact forest units in the subwatershed study area currently contain a wider diversity of adapted tree species, including bur oak, shagbark hickory, and Freeman maple. Coniferous species such as white cedar, eastern hemlock, balsam fir and white pine were probably relatively common at the time of original settlement. Project Number:

78 The CVC Wetland Restoration Strategy (Dougan & Associates 2009) concluded that wetlands that are located on relatively flat sites with fine textured soils, and reliant on localized catchment systems, are the most sensitive to the climate change characteristics that are anticipated in this portion of southern Ontario. The SPNHS and Principles have defined certain committed future conditions, including the relocation and lowering of watercourses, elimination of some low constraint headwater drainage features (mitigated with swale creation), and confinement of the Regional regulatory event within stream corridors. Many forest units contain areas that fall within the existing Regional Storm floodplain; in most cases these features will probably be isolated from flooding events under future conditions. This implies that the future hydroperiods could return to historic seasonal flooding patterns that are beneficial and appropriate to individual units or specific wetland areas within the units. Contributions from upstream areas will be eliminated, resulting in a more normalized hydroperiod within these features. Modelling of the existing watercourses indicates that overbank events do not occur regularly today; on this basis it is considered likely that the existing channels represent outlets for sub-catchment units that were previously more isolated and self-contained. Forest canopy emergence results in relatively rapid drawdown of stored surface and shallow groundwater once leaf cover emerges, and typically empties most pools in clay plain forests by early summer. In particularly wet summers, pools may be temporarily refilled. Tree cover is more efficient at raising evapotranspiration rates relative to other wetland covers (i.e. marsh or thicket), however there are extenuating factors related to air temperature, wind and species composition. Although there is limited literature on the subject, loss of canopy from physical destruction, disease or pest infestations likely has significant implications for evapotranspiration rates. Repeated episodes of Dutch elm disease on lowland stands dominated by American elm are usually followed by conversion to emergent marsh. Green ash dominated swamps have gradually displaced elm over time due to the adaptiveness of this ash species. Emerald ash borer (EAB) is spreading rapidly in southern Ontario and will likely transform the hydrology of ash-dominated swamps; research on the effects of EAB on ash-dominated wetlands is currently being initiated in Minnesota. (ref. ) Groundwater modelling conducted for the Subwatershed Study has indicated the potential for fine-scale lowering or raising of the water table. The steady state groundwater model represents average annual hydrogeologic conditions and relative changes to water levels due to changes in recharge but does not accurately represent fine scale absolute values of the water table elevation (i.e. refer to Phase 1 Section ). There are numerous extenuating factors that either mask or otherwise affect groundwater effects at the site specific scale due to the heavy soils, including vegetative cover variation (i.e. canopy species and structure, past logging effects on canopy and micro drainage, infestations of pests and diseases) and influences of current farming practices (changes from crop rotation and tilling practices, which also affect runoff quality), and creation and periodic maintenance of swales under active farming uses, Adaptive Management of Hydroperiods within Natural Features As discussed above, the existing forested wetlands have undergone significant disturbance and alteration in the past. Restoration will involve the reinstatement of a more normative pool and Project Number:

79 wet soil hydrology, and the management of the future changes as summarized above. Where features currently receive inflows from adjoining catchments that will be partially urbanized, the identification of existing flow patterns based on contour review, seasonal field observations, and water monitoring is the first step to rationalizing existing versus future flows for the receiving areas within the feature. The management of flows to wetlands should ideally be addressed using flows that are buffered from effects of impervious surface runoff. This can likely be achieved within the buffers, using created micro depressions to store smaller event inflows, and compensation swales to divert excessive flows once event thresholds are met. The adaptive components can be addressed through integration of measures in each location that allow subtle enhancement or reduction of local infiltration storage within the buffers. It is assumed that the buffers will be delivered in an operational state consistent with the MOU and an identified natural feature adaptive management approach. This would imply that there will be seeding with cover(s) leading to appropriate successional cover. The management of flows from surface catchments into specific habitats will need to be carefully addressed, and may in some cases require subtle works (micro berms, swales, french drains) to ensure that connections and containment are maintained. Horizontal interflow in the fine-textured soils in the study area may extend m from infiltration sources to features, allowing for functional extensions by insertion of pit and mound capture areas, and micrograding to retain moisture within the buffers. The scale of interventions should be carefully considered in terms of the effects on vegetation cover as well as potential benefits to biota reliant on seasonal pools. Trails will require small culverts at regular intervals to ensure hydrologic connectivity and prevent trail flooding; trails can also serve as flow partitioning or detention barriers, absorbing flashiness of inflows from more significant storm flows. The net benefit of the redundancy-based approach to buffers will be the extension of habitat functions and increased resilience of the natural system. As discussed under buffers, wetland cover can also provide effective deterrence to keep pedestrians on trails extending through the buffer. The goal of buffer grading should be to diversify water retention in terms of area, depth and hydroperiod longevity, which will have significant benefits to amphibians and other ecosystems components that are reliant on vernal systems. This diversification is considered a key element of adaptive management. Given the characterization of the groundwater resources (i.e. general recharge conditions and relatively low groundwater flux) and further monitoring at the EIR stage, maintenance of hydroperiods in the vicinity of natural features is generally assured except under very localized circumstances. The elimination of agricultural practices, and introduction of buffers that will evolve towards woody cover over 1-3 decades, should stabilize evapotranspiration rates over time, and will normalize seasonal ground and surface water flux that is currently responding to agricultural conditions. It is anticipated that restoration and maintenance of appropriate hydroperiods can be effectively achieved irrespective of the stream relocations and lowerings. The redundancy approaches described above will moderate the flashiness of flows from urban portions of subcatchments, and buffer water quality along the inflow network. Swales, microtopography and (in some cases) trail beds will allow exceptional events to bypass the natural features. Adaptive management (based on monitoring outcomes) to reinforce water retention around natural features, or to reduce retention, can be achieved through micro- Project Number:

80 manipulation of swale inverts, use of micro scale check dams, and use of the trail base equipped with small culverts at appropriate intervals. The restoration of the wetlands located within the vicinity of the existing City Park (Natural System Integration Site R on Phase 1 Figure NSI 1) will be largely reliant on the management of runoff and flows within existing dug swales and channels in the vicinity. The EIR will provide options to increase water inputs into these features, while maintaining dry conditions in the City park. Given concerns regarding flooding in the adjoining park, low berms can be utilized to contain flooding, and check dams on the ditches can allow adjustment or refinement of optimal water levels within the wetlands. The future trail bed along the utility corridor may serve as a low berm to manage inundation and flows between subcatchment areas. The restoration of wetland cover on the gap between the southern forest lobes can be achieved through succession, direct seeding of prepared field, and/or plantings. The Principles indicate that restoration of this area is not the responsibility of the landowners, however the overall master drainage plans will need to accommodate the water balance needs of this area. Adaptive management of natural features should always be planned within a risk management framework that assesses potential outcome scenarios, and responses. For example, restoring the water table in an existing forested wetland system (such as forested wetlands in the vicinity of the City Park) presents potential risks such as drowning of trees that have adapted to lower water table conditions over many decades, with the result that tree rooting is weakened. This may represent a logical outcome of restored groundwater functions, but it will have implications regarding public perception and/or safety concerns that should be anticipated when the restoration plan and accompanying adaptive management plan are developed. Integration Practices Swales Swales created to address drainage density, will provide opportunities for habitat creation within buffers, stormwater facility blocks, parks and other areas where elements of naturalized cover are likely to be encouraged. Swales will assist in the distribution of surface water to the existing and new terrestrial units, and design should be integrated with the water balance maintenance measures discussed above under adaptive management of water balance. Trails Trail layout will reflect a careful analysis of key sensitivity areas, as well as desirable activity nodes. This will be addressed in the EIR through updated feature inventories, analysis of topography and micro drainage, and prioritization of protected areas. In general, trails should be separated from key habitats that support interior conditions, as well as wetland features. A significant stressor to native wildlife, related to pedestrian trails, is the presence of domestic dogs, which mark habitat edges and affect canid predators and small mammals. These effects will obviously be more pronounced if dogs are off-leash. Signage and enforcement of a leash by-law, and establishment of designated off-leash parks areas can help discourage the tendency for pet owners to release their dogs while on trails. Project Number:

81 Screen plantings and specific placement of deterrent shrubs (raspberry, hawthorn) as well as swamp thicket creation, can effectively chaperone trail users to avoid sensitive encroachment into natural features. Rubble/rock piles can also deter passage while providing cover for small mammals and herpetofauna. Fencing (post and wire) is also effective especially if planted with creeper and vine cover that retard pedestrian and pet access. Monitoring of trails is critical to maintaining their integrity and function within the vicinity of the NHS. Drainage management and deterrent measures should receive regular review (monthly in active use seasons). Trails are also discussed as potential opportunities to manage surface water runoff between the development areas and natural features; this is discussed above. The role of the EIR is to plan the trail system in conjunction with other integration measures for the NHS. Adjoining Land Uses Parks and stormwater management facilities offer the opportunity to reinforce NHS functions through provision of naturalized elements, and adding landscape porosity i.e. connections for wildlife and species movement in the vicinity of the NHS. This requires the careful treatment of edges that interface the NHS, use of fencing that deters human access while allowing wildlife movement (e.g. page wire). Plantings can be used to screen features from activity areas, while allowing wildlife passage when human activity levels are lower or seasonally absent. The EIR should examine each public use adjacent to the NHS, to identify opportunities to improve functionality and minimize impacts to the natural features Stormwater Management Hydrology Conventional stormwater management and the implementation of LID BMP s provides the flow control and water quality control necessary for watercourse functions, fisheries habitat, and also maintains the water budget. An integrated approach has been conducted to sizing stormwater management facilities in order to maintain the existing flow regime and water budget. The LID BMP s are required to provide the water budget maintenance as conventional stormwater management does not provide the infiltration required. Hydrogeology As discussed in Section above the maintenance of groundwater levels is provided through stormwater management. The ability to reduce overland flow, in part, through infiltration practices is inherently linked to the soil characteristics. Within the Mount Pleasant study area the lower permeability of the Halton Till constrains the extent of infiltration. In addition the seasonal high water levels would also constrain the infiltration practices. Conceptually, a reduction in recharge from development would reduce groundwater levels in areas thereby increasing the potential for infiltration. Project Number:

82 Although sand and gravel lenses may exist within the till and are more permeable with respect to infiltration the existing water levels within these units may constrain the ability to infiltrate water. Section provides additional groundwater related aspects related to stormwater management. Terrestrial System Stormwater management facilities are important features to be considered as adjunct to the SPNHS because i) they are fundamental linkages between landscape hydrological functions, receiving watercourses, and their corridors; ii) they will occupy a significant area of naturalized cover in the built landscape adjacent to corridors; and iii) it has been well documented that they are functionally important to, and regularly utilized as habitats by upland, wetland and aquatic biota. Stormwater Management Integration with Natural Feature Adaptive Management The primary integration of stormwater management with the NHS relate to the maintenance of hydroperiods and water quality within the natural features. This is discussed above in Section The primary sources of flows to the natural system will emanate from swales, roof collector drains, and foundation drain collectors. The strategies for storage and buffering of these flows in support of the NHS are addressed in Section A key management approach is the use of buffers to eliminate the flashiness of runoff, while contributing to interflow enhancement through redundancy measures i.e. creation of micro topography that effectively stores and gradually transmits water to the natural system. Swales can provide overflow relief for larger events. Adaptive management to either further reinforce water retention around natural features, or to reduce retention based on monitoring, can be achieved through manipulation of swale inverts, use of micro scale check dams, trail base with small culverts etc. Stormwater Management Facilities as SPNHS-supportive Naturalized Elements According to their performance objectives, stormwater management facilities are viewed as posing a potential risk of exposing biota to contaminants. Urban facilities are currently designed to be regularly monitored and managed in the built landscape, and assuming that due diligence is respected in this maintenance, these facilities are intended to provide net functional benefits to the ecosystem. Concerns over post-development water quality have resulted in an agreement to establish a Maintenance and Retrofit Fund to ensure an aggressive facility monitoring and enhancement strategy for Mount Pleasant. Low Impact Development is bringing stormwater management practices into the built fabric, thereby providing green development opportunities within the developed area. Efforts to integrate these systems will form a useful adjunct to the SPNHS. Although stormwater management facilities are not included within the SPNHS, they represent nodal opportunities to expand naturalized cover in key locations along corridors, and will enhance SPNHS functions. Stormwater management facility blocks may encompass over 1 ha Project Number:

83 in area, and may be shaped and positioned to provide separation of intensive development from corridors or natural features. It is also desirable to integrate swales within facility footprints to help achieve the drainage density targets. The benefits of these integrated elements as linkages, localized wetland pool creation opportunities that contribute to the overall wetland target, and associated plantings, should be given careful consideration in the design of the facility footprints as part of the EIR and detailed design studies. The and CVC have planting policies for stormwater facilities. Native plant materials indigenous to the Credit River watershed should be utilized in landscaping of facilities, and to provide benefits such as wetland cover and shading of facility pools. Project Number:

84 3. IMPLEMENTATION PLAN 3.1 Introduction This section outlines the specifics associated with the implementation of the Management Strategy related to phasing considerations, financing/cost sharing considerations, operations and maintenance, monitoring and adaptive management plan, terms of reference for future studies such as the Block Plan EIR S, Stewardship and Education programs, and future directions for research and development. 3.2 General Implementation Process The general environmental implementation process, including how the Subwatershed Study fits in the planning and approval processes, has been provided within Figure 3.1. Figure 3.1 demonstrates that the Subwatershed Study is a follow-up requirement to the Environmental Open Space Study which was completed in 2005 and was a supporting process to the Region and City Official Plan Amendments for the s urban boundary expansion. Subsequent to completion of the Open Space Study and approval of the Official Plan Amendments, the Secondary Planning process has required the completion of the Subwatershed Study and the determination of the discipline specific recommendations. Each Phase of the Subwatershed Study has provided input for consideration into the next level of environmental process reporting, the Environmental Implementation Reports (EIRs). The EIRs provide the detailed environmental recommendations for each Block Plan. Discussion of the EIR requirements has been provided in Section 3.3. There are two additional steps in developing the final environmental systems for the Mount Pleasant Community after the EIRs, which are the Functional Servicing Plans and the Engineering Submission of Subdivision Plans. Each step provides more detailed information on how the recommendations of the Subwatershed Study are to be addressed. The Implementation Process schedule as developed by the has been provided in Phase 3, Appendix H, along with more detailed information on sub-area Block 51-1 planning process. Project Number:

85 Approval Agencies - Environmental Planning Process Municipal Planning Process Municipalities Provincial Agencies Conservation Authorities Public Water Management Strategy Environmental Open Space Study Regional/Local Official Plans Regional/Local Official Plan Amendments Municipalities Conservation Authorities Landuse Study Landscape Scale Subwatershed Study Transporation Analysis Strategy (Class EA) Public Phase l Subwatershed Characterization Phase II Subwatershed Impact Analysis Phase III Recommendation Management Strategies & Implementation Phase IV Long Term Monitoring Plan Secondary Plans Environmental Implementation Report (EIR/MESP) 2 Block Plans Municipalities OPA Approval Conservation Authorities EIS SWM Hydrogeology Geotechnical Geomorphology Natural Channel Design Recommendation of EIR/MESP Implementation and Agreements Natural Feature Mitigation Monitoring Functional Servicing Report Draft Plan Submission Conditions of Draft Plan Approval Municipalities Engineering Submission of Subdivision Conservation Authorities Provincial and Federal Agencies (Permitting) Plan of Subdivision Approval, Registration Subdivision Agreement Development, construction Grading and Servicing Building Building Construction Figure 3.1 Project Number:

86 3.3 EIR / CFCP Requirements EIR requirements are provided for each of the disciplines, hydrogeology, hydrology, hydraulics, surface water quality, stream morphology, fisheries and terrestrial. Discussion regarding how the targets from the Subwatershed Study have to be included for each of the disciplines is part of the EIR. Each discipline must be examined in an integrated approach that would discuss the fieldwork required, functional design process, protection and restoration of the Natural Heritage System, including woodland, wetlands and stream corridors as protected through the land use planning process and Subwatershed Study. Study requirements for the stormwater management and LID BMP functional design need to be outlined. Sediment and erosion control requirements would also be discussed EIR Requirements Hydrogeology The Geology and Hydrogeology section of the Environmental Implementation Report Terms of Reference (July 7, 2010) have been reviewed. The EIR TOR outlines the purpose of the detailed hydrogeological study is to characterize existing hydrogeological conditions, quantify potential groundwater-related impacts of development and determine the need for, and nature of, any mitigation measures required to protect the hydrogeological features and functions within the study area... The scope of work for the Site Characterization and Requirements for Proposed Development Plan is sufficiently detailed and is expected to address the purpose of the EIR study with the following suggested revisions: The existence and potential removal of tile drainage should be recognized. Removal may increase the local water table and could potentially reduce short term groundwater discharge to local surface features. The potential impacts of this should be qualitatively assessed in the EIR. Within a practical context the extent of hydrogeologic characterization and groundwater balance related to the terrestrial features should be correlated with the realistic ecological dependence based on actual field observations and the expected groundwater discharge/recharge function (Refer to Section ). Stormwater Management and Hydraulics The SWS study has recognized that stormwater quality retrofit opportunities beyond the Mount Pleasant community are required to work towards CVC's objective of a zero net increase in contaminant annual loadings. It is recognized that the City's 2005 Stormwater Retrofit Study will be updated to identify and prioritize stormwater retrofit sites as part of a strategy to reduce contaminant loadings within watercourses located within municipality. The is further committed to ensuring a sustainable funding source for implementation of retrofits (ref. Stormwater Management Facility Maintenance fund see Section 3.5). As part of the update, details of retrofit opportunities such as drainage area, impervious coverage, facility(s) sizing and preliminary design, will be required. Project Number:

87 The Subwatershed Study has provided the following: Stormwater management facility locations and associated drainage areas Flood Control Volumetric Requirements and Flow Release Rates based on post to predevelopment control Regional Storm Volumetric requirements based on post to pre-development control LID BMP capture rates for land uses based on water budget balance objective Erosion Control Volumetric Requirements and flow release rates based on maintaining existing duration of critical flows Stormwater quality control requirements as per MOE s Level One (Enhanced), with the recognition of the need to work towards CVC s zero net increase in annual loadings based on a stormwater quality retrofits beyond the Mount Pleasant Community. Watercourse corridor widths based on consideration of hydraulics, meander belt, NHS and buffer requirements Watercourse corridor riparian storage requirements To provide additional detail to the foregoing Subwatershed Study requirements and recommendations, the EIR should provide the following stormwater management and hydraulic information: Drainage areas and impervious coverages draining to each stormwater management facility. Preliminary stormwater management facility layout, grading and outlet control details. Stormwater management facility flood control volumes based on the Subwatershed Study volumetric and flow release requirements. Verification of post to pre-development flow at target flow nodes will be required using the Subwatershed hydrologic modelling. Regional Storm control details whether on-line within the watercourse corridor and/or within the proposed stormwater management facilities. Details should include discharge storage rating curves, watercourse corridor flood elevations and limits, control structure(s) details and potential impacts to infrastructure and public lands. Details of generic LID BMPs such as sizing, design calculations, location, constructability and maintenance requirements. Stormwater management facility erosion control volumes based on the Subwatershed Study volumetric and flow release requirements for East Huttonville Creek and as potentially refined within the EIR process for Fletcher s Creek. Verification of critical flow durations meeting existing durations at target flow nodes will be required using the Subwatershed hydrologic modelling. Stormwater quality control volumes based on MOE Level One control requirements. Fee to be generated per stormwater management pond to assist in implementing the City s Retrofit Study and program.. Identification of thermal mitigation measures to be implemented. Watercourse grading, crossing details, hydraulic modelling and flood elevations and riparian flood storage calculations. Riparian flood storages should match existing Project Number:

88 storage for the subject creek reaches. Determine potential impacts to the proposed NHS system from Regulatory Storm flooding and develop mitigation measures, if needed. Preliminary design for storm sewer, foundation drains and roof drainage collection systems including details of systems draining to existing natural features and associated buffers. Water budgets to existing natural features should be provided, describing how existing drainage will be maintained and if not maintained how it would be mitigated. Terrestrial / Natural Heritage System The Management Practices discussion (Section 2.2.7) provides direction for many initiatives and implementation details to be considered or addressed in the EIR. The EIR Terms of Reference (July 2010) that were negotiated by the MPLG,, CVC and MNR are extensive and comprehensive with respect to the implementation of the SPNHS. They are presented in Appendix F. The following summarizes the key management practices identified in the Subwatershed Study that are relevant to the EIR: Existing Natural Features and Attributes Feature boundaries confirmation as per the SPNHS and Principles Updated feature documentation and community mapping including features outside of SPNHS, as appropriate (i.e. Vegetation Assessment Guidelines, Woodland Management Plan, etc.) Terrestrial system opportunities Cover Targets Invasive Species Management Species at Risk Terrestrial System Management after Development Riparian Corridors Trails within corridors Plant salvage within corridors Corridor habitat enhancement Corridor vegetation strategies Road crossings and wildlife passage Restoration and Enhancement Areas Terrestrial Restoration Opportunities On-line and off-line wetland creation Buffers Reinforcing deterrent and habitat enrichment functions of buffers Buffer roles in Adaptive Management Integration Watercourse Systems Floodplain connectivity changes Swale compensation and LID Extreme flow events Project Number:

89 Integration Natural Heritage System Surface and groundwater regimes of natural features Adaptive Management of Hydroperiods Within Natural Features Integration Practices Swale mitigation Trails Adjoining Land Uses Integration Stormwater Management Stormwater management integration with natural feature adaptive management Stormwater management facilities as SPNHS-supportive naturalized elements To supplement the foregoing Subwatershed Study requirements and recommendations, the EIR should provide the following terrestrial and NHS-related information: Identify cover targets (plant community models; ELC-based vegetation communities and their relative extent) and targeted indicator species (flora and fauna) for the existing natural areas within the SPNHS, corridors, and restoration areas Recommend management approaches by species and area Consider all terrestrial and NHS targets and opportunities, and summarize where addressed through EIR actions Consider all species at risk and include general to specific measures to ensure that basic habitat and safe movement requirements are addressed Identify general habitat management requirements, for natural areas, buffers and corridors CFCP Requirements The terms of reference for the CFCP are being established through dialogue among DFO, OMNR, CVC, and the Mount Pleasant Landowners Group. A draft Terms of Reference is provided in Appendix G. The CFCP will include a description of the project and the existing conditions and will describe the proposed direct alterations to watercourses. In addition to the direct alteration of the watercourses and headwater drainage features, the CFCP will also outline proposed site alterations that have the potential to affect aquatic resources, species-atrisk and fish habitat such as wetland recreation, NHS enhancement, stormwater management practices and road and services crossings of the creeks. It will scope issues related to fish habitat such that agency review of the document will ultimately lead to agreement in principle of various conceptual designs for projects such as watercourse crossings, and channel lowerings and realignments, and channel remediation and drainage feature enhancement. By obtaining agreement in principle for various proposed alterations, the document should serve to guide future detail designs for specific projects and lead to a streamlined approval process for future permitting in accordance with an approved CFCP. 3.4 Staging and Sequencing Plan The requires the preparation of a Growth Management Staging and Sequencing Strategy Report and associated plans that outline the staging, timing and delivery of key infrastructure required for development to occur within a block plan in an orderly and Project Number:

90 efficient manner. The Strategy and plan provide a preliminary overview of the potential development phasing and associated considerations and principles with respect to the implementation of the transportation and transit system, development lands, community uses and parks, stormwater management and erosion and sediment controls, and the creation of the NHS. The phasing of development should avoid out-of-phase works whereby the developers in consultation with the City and CVC develop a detailed plan which considers temporary works and the prioritization of NHS elements and infrastructure, as well as potential out of phase construction management. Development Phasing There are two primary development phases in the Mount Pleasant Community; Block Plan Sub- Area 51-1, which is essentially bounded by Mayfield Road to the north, Creditview Road to the east, Mississauga Road to the west, and Bovaird Drive to the south, and Block Plan Sub-Area 51-2 which is essentially the balance of the Mount Pleasant Community lands, east of Creditview Road to McLaughlin Road, and Mayfield Road to Wanless Drive. A preliminary staging concept for Block Plan 51-1 has been outlined in the Mount Pleasant Secondary Plan Block Plan Area 51-1 Growth Management Staging and Sequencing Strategy Report, July 9, 2010 as per Table 3.1 and depicted on Figures 3.2 and 3.3. Staging of Block Plan 51-1 has been established using three stages with full build-out expected by These staging and sequencing plans will be finalized through the Strategy Report. Table 3.1. Estimated Build-out Rate Year Estimated Residential Build-Out (Ground Related No Apartments) units ,250 units ,250 units ,250 units ,250 units Total 5,626 units NHS and Stormwater Infrastructure Implementation Phasing While the NHS and supporting stormwater infrastructure will be phased in consideration of the development and staging of the Block Plan, the construction of these key elements of the Mount Pleasant Community will need to be based on a strategy for the conservation and management of ecosystem features and functions that respects requirements and criteria outlined in legislation (e.g. Fisheries Act, ESA), the final CFCP, watershed management plans (e.g. CRFMP timing windows), etc. Project Number:

91 Figure 3.2 Project Number:

92 Figure 3.3 Project Number: