879 River Road Development Headwaters Drainage Assessment (HDA)

Transcription

1 879 River Road Development Headwaters Drainage Assessment (HDA) July 2018 Prepared for Richcraft Homes

2 July INTRODUCTION Background Site Overview METHODOLOGY EXISTING CONDITIONS Drainage Feature Overview Hydrological Characteristics Channel and Riparian Characteristics Fish Community and Fish Habitat Amphibian Habitat Summary of Habitat Quality POTENTIAL DEVELOPMENT IMPACTS CLASSIFICATION MANAGEMENT RECOMMENDATIONS - MITIGATION Flow Mitigation Construction Stage Mitigation DETERMINATION CLOSURE REFERENCES... 21

3 July 2018 LIST OF FIGURES Figure 1: Site Overview Figure 2: Survey Sites Draft Plan of Subdivision LIST OF TABLES Table A: Hydrology Classification Table B: Channel Measurements Table C: Riparian Classification Table D: Amphibian Survey Results Appendix A Site Photographs

4 July INTRODUCTION 1.1 Background McKinley Environmental Solutions (MES) was retained by Richcraft Homes Inc. to complete a Headwaters Drainage Assessment (HDA) for the Drainage Features that are present within the 879 River Road property, located in Ottawa (Ontario) (the Site). MES was also retained to concurrently prepare a Combined Environmental Impact Statement (EIS) and Tree Conservation Report (TCR) (under separate cover) (MES 2018). The Drainage Features are found along the southern boundary of the Site, and flow in an approximately east to west direction. This HDA report was completed in order to provide background information, documentation of current conditions, an impact assessment, classification, and management recommendations for the Drainage Features. As described in greater detail below, Richcraft Homes Inc. proposes to decommission the Drainage Features as part of the development of a residential subdivision at the 879 River Road Site. Ultimately, the proposed removal of the Drainage Features will be subject to review by the Rideau Valley Conservation Authority (RVCA) and will require approval under the Development, Interference with Wetlands and Alteration to Shorelines and Watercourses Regulation (O.Reg. 153/06). The 879 River Road property is approximately 3.24 ha in size. The Site is currently zoned Development Reserve and is vacant. The Site will be developed as a subdivision with approximately 125 residential units. There are no designated parkland, open space, or institutional blocks identified within the future subdivision. The Site will be serviced with municipal sewer and water. Stormwater servicing will be provided by directing flows to the proposed storm sewers, which will ultimately outlet to the Riverside South Pond 5. The natural heritage features, potential impacts, and mitigation associated with the subdivision development are described in the concurrently prepared Combined EIS and TCR (under separate cover) (MES 2018). Refer to the Combined EIS and TCR for additional information regarding natural heritage features.

5 July Site Overview The Site was historically farmed and is currently dominated by Fallow Agricultural Fields (Graminoid Meadow). The northeast corner of the Site includes a small recent regrowth Fresh-Moist Ash Poplar Deciduous Forest. Two (2) isolated tree stands, a Coniferous Hedgerow, and a Deciduous Hedgerow are also present within the Site. Refer to the Combined EIS and TCR (MES 2018) for additional detail regarding the vegetation communities. At the time of report preparation, the area directly north of the Site had recently been cleared and was undergoing topsoil stripping as part of the approved Riverside South Development Corporation (RSDC) Phase 15 development. The area east and southeast of the Site includes recently Fallow Agricultural Fields (Graminoid Meadow), which are designated for future development by Claridge Homes. The property southwest of the Site includes a single detached residential home. River Road is present west of the Site, beyond which are several developed residential properties with single detached houses.

6 River Road July River Road Development Headwaters Drainage Assessment (HDA) Recently Cleared Area No Tree Cover W N E S Culvert Please Note: This is not a legal land survey. All dimensions and locations are shown as approximate. - Development Limits - Drainage Features - Overland Flow (No Defined Feature)

7 ORIGINAL SHEET - ARCH D W:\active\ _879 River Road\design\drawing\xref\ DP - JP.dwg 2018/07/04 1:33 PM By: Palangi, Jupiter 6.52m (3.30m MIN) 6.00m 6.72m 3.21m 6.0m MIN (2.60m MIN) (2.60m MIN) 4.07m 2.60m STREET NO m (6.00m MIN) BLOCK 9 STREET NO m 30.50m 18.00m 30.50m 30.50m (1.50m MIN) 5.75m (2.60m MIN) (2.60m MIN) 3.63m 4.73m 6.90m 6.90m BLOCK RESERVE RIVER ROAD Accepted C/L Road BLOCK 3 BLOCK 2 BLOCK 1 RESIDENTIAL EXISTING 8 UNITS 26 BLOCK m UNITS 51 BLOCK 21 BLOCK m (6.00m MIN) TOTAL UNITS =125 (1.50m MIN) (6.00m MIN) (6.00m MIN) (3.30m MIN) 4.58m (2.60m MIN) 30.54m 2.60m R38.00m 6.46m (3.30m MIN) (3.30m MIN) 6.46m 8 UNITS BLOCK m 30.50m UNITS 2.63m BLOCK m 2.60m 69 (2.60m MIN) 71 8 UNITS 2.60m 72 (3.30m MIN) BLOCK (3.30m MIN) 3.68m BLOCK m 18.00m (3.30m MIN) m PART 1 PLAN 5R m (3.30m MIN) 6.69m (6.00m MIN) m BLOCK BLOCK STREET NO. 4 BLOCK 4 BLOCK 10 STREET NO. 2 BLOCK 13 BLOCK 16 BLOCK 17 BLOCK 5 BLOCK 7 BLOCK 6 BLOCK 14 BLOCK m 8.94m 3.32m (3.30m MIN) 5.13m 14.50m 8.00m 6.00m (6.00m MIN) 1.86m 5.10m (6.00m MIN) 6.01m 6.00m RSDC PHASE 15 NORTH PROPOSED RESIDENTIAL m 2.77m BLOCK BLOCK 6 (3.30m MIN) 5.10m STREET NO.1 (3.30m MIN) 6.45m 10.16m (3.30m MIN) 3.58m BLOCK m 6.12m 9.76m m BLOCK 7 BLOCK m CLARIDGE HOMES PROPOSED RESIDENTIAL PHASE 2 LANDS 8.61m 125 Stantec Consulting Ltd Clyde Avenue Ottawa ON Tel Copyright Reserved The Contractor shall verify and be responsible for all dimensions. DO NOT scale the drawing - any errors or omissions shall be reported to Stantec without delay. The Copyrights to all designs and drawings are the property of Stantec. Reproduction or use for any purpose other than that authorized by Stantec is forbidden. Legend Notes X XXXX XX XX XX.XX.XX Revision By Appd. YY.MM.DD File Name: 16040XXXX-XX XX XX XX XX.XX.XX Permit-Seal Dwn. Chkd. Dsgn. YY.MM.DD Client/Project CLIENT CLIENT2 PROJECT DESCRIPTION PROJECT DESCRIPTION2 City, State/Prov Title OPT 3-WALKOUT TOWNS+BACK TO BAC TITLE2 TITLE3 Project No XXXX Scale Drawing No. Sheet Revision XX-X X of X 0

8 July METHODOLOGY The field component of the Headwater Drainage Assessment (HDA) was undertaken following the Evaluation, Classification and Management of Headwater Drainage Features Guideline (TRCA 2014). The sampling sites included 40 m upstream and 40 m downstream of each constriction or confluence. As shown in Figure 2, three (3) constrictions were identified, requiring three (3) Survey Sites. Each upstream and downstream drainage feature segment was measured at each of the three (3) Survey Sites. As shown in Figure 2, an undefined Overland Flow Feature was documented west of Site #2. This feature was not surveyed in detail as part of the HDA field investigation, due to the fact that the Overland Flow Feature had no defined channel. Surface runoff was observed to flow from the north towards the south in the vicinity of the Overland Flow Feature, but due to the lack of a defined channel, the Overland Flow Feature was not investigated in detail. Any runoff coming from the undefined Overland Flow Feature would be captured by the surveyed Drainage Features, and would be reflected by measurements taken downstream at Survey Site #1. Similarly, the roadside ditches along the east side of River Road were observed to be dry throughout the survey period, even in late March during the spring freshet. As such, it was determined that the roadside ditches contribute negligible flow to the Drainage Features, and hence they were not investigated in detail as part of the HDA field surveying. Site surveys included the following: OSAP Module S4.M10 Assessing Headwater Drainage Features (Stanfield et al. 2013): This includes an assessment of hydrological and physical functions. Parameters measured are summarized in Tables A, B and C. These include the watercourse type, flow conditions, bankfull width, channel depth, riparian corridor vegetation, and connectivity. Flow measurements were completed on March 30 th (spring freshet), May 23 rd (early spring) and July 3 rd, 2018 (midsummer). Channel measurements were completed during the March 30 th, 2018 Site visit. Prior to the March 30 th Site visit, significant spring snow melt was observed, and there was approximately 10 mm of rain the day before (March 29 th ). Light rain (<5 mm) occurred the day before the May 23 rd Site visit. No rain occurred for approximately 48 hours prior to the July 3 rd Site visit. Fish Survey: Water levels throughout May and June were too shallow to allow the Drainage Features to be sampled using a backpack electrofisher (Stanfield 2013). Instead, on May 23 rd a dip net was used to sample areas of standing water throughout the Drainage Features. Marsh Monitoring Program Amphibian Call Counts (Konze and McLaren 1998): Amphibian breeding habitat was identified according to the Marsh Monitoring Program Amphibian Call Counts Method (Konze and McLaren 1998). This method includes three (3) night time surveys in April, May, and June to survey for amphibian breeding activity by listening for frog calls. Surveys were conducted on April 23 rd, May 21 st, and June 15 th, Conditions on April 23 rd included clear skies and temperatures of 9⁰C. Conditions on May 21 st included 20⁰C and clear skies.

9 July Conditions on June 15 th, 2018 included clear skies and temperatures of 18⁰C. Amphibian call counts were conducted in the upstream and downstream portions of the Drainage Features. Amphibian survey results are included in Table D.

10 River Road July River Road Development Headwaters Drainage Assessment (HDA) N W E S 1 3 Please Note: This is not a legal land survey. All dimensions and locations are shown as approximate. Culvert 2 Flow Direction - Development Limits - Drainage Features - Overland Flow (No Defined Feature) # - Survey Sites

11 July EXISTING CONDITIONS 3.1 Drainage Feature Overview Survey Sites are shown in Figure 2. Site photographs are included in Appendix A. The Site slopes gradually from an elevation of approximately 90 m ASL in the east to approximately 88 m ASL in the west (at River Road). The Site rises slightly towards the north, such that surface runoff flows from the north of the Site towards the Drainage Features that are present along the southern Site boundary. The Drainage Features themselves flow from east to west. As described below, the majority of surface flow is contributed from the channelized farm drains that drain the Fallow Agricultural Fields (Graminoid Meadow) located east and south of the Site. Flow from the Fallow Agricultural Fields accumulates within a channel that extends along the southern boundary of the Site. Flows cross beneath River Road through a 120 cm CSP culvert, before entering a ravine on the west side of River Road. Flow from the Site ultimately outlets to the Rideau River, approximately 360 m west of River Road. As noted above, surface flow is contributed to the Drainage Features by the undefined Overland Flow Feature located west of Site #2. This feature was not surveyed in detail as part of the HDA field investigation, due to the fact that the Overland Flow Feature had no defined channel. Any runoff coming from the undefined Overland Flow Feature would be captured by the surveyed Drainage Features, and would be reflected by measurements taken downstream at Survey Site #1. The roadside ditches along the east side of River Road were observed to be dry throughout the survey, and hence are likely to provide negligible hydrological input to the system.

12 July Hydrological Characteristics Hydrological characteristics of the Drainage Features are summarized below in Table A. Water levels throughout the Site were at their highest during the spring freshet (March), during which average water depth throughout the system varied between approximately 87 mm and 243 mm. The deepest portion of the Drainage Features was Site #1 upstream. Site #2 upstream (south tributary) and Site #3 upstream (south tributary) both had comparatively shallow average water depths. During the spring freshet, all segments experienced comparatively substantial flow volumes, with the exception Site #2 upstream (south tributary) and Site #3 upstream (south tributary), both of which had minimal flow volume. During late spring (May), water levels and flow rates were observed to decline significantly compared to the spring freshet (March). By May, water depths varied between 0 mm and 167 mm, with Site #3 upstream (south tributary) observed to be dry. The wetted width of the channel also declined significantly. By May, only Site #1 downstream, Site #1 upstream, and Site #2 downstream were flowing, and each of these segments had minimal flow volume. The remaining segments had standing water with no flow, or were dry in the case of Site #3 upstream (south tributary). By mid-summer (July), the majority of the Site was observed to be completely dry, with no standing water present in most segments. Only Site #1 downstream and Site #1 upstream continued to have standing water, with an average water depth of 27 mm and 17 mm (respectively). No flow was observed within Site #1 during mid-summer. In summary, the bulk of flow from upstream areas is contributed from the east. In addition to flows coming from the east, Site #2 upstream (south tributary) and Site #3 upstream (south tributary) provided minimal flow volumes during the spring freshet, and negligible input for the remainder of the survey period. The undefined Overland Flow Feature located west of Site #2 was observed to provide minor overland flow during the spring freshet, but was otherwise dry. The roadside ditches along the east side of River Road did not appear to provide significant input to the system. The Drainage Features convey substantial flows during the spring freshet (March), but flows decline sharply by late spring (May), such that the majority of the system only features very shallow standing water. By mid-summer (July), the majority of the Site was dry.

13 TABLE A: HYDROLOGY CLASSIFICATION SITE SEGMENT FEATURE TYPE AVERAGE WATER DEPTH AVERAGE HYDRAULIC HEAD FLOW REGIME* WETTED WIDTH (cm) (mm) (mm) Mar.30 May 23 July 3 Mar.30 May 23 July 3 Mar.30 May 23 July 3 Mar.30 May 23 July 3 Site #1 - River Road Site #2 - Field Drainage Confluence Downstream Defined Natural Channel Substantial Minimal No Flow Upstream Defined Natural Channel Substantial Minimal No Flow Downstream Defined Natural Channel Substantial Minimal Dry N/A Upstream (South Tributary) Channelized Farm Drain Minimal No Flow Dry N/A Upstream (East Tributary) Channelized Farm Drain Substantial No Flow Dry N/A Downstream Channelized Farm Drain Substantial No Flow Dry N/A Site #3 - Farm Upstream (South Drainage Tributary) Channelized Farm Drain Minimal Dry Dry N/A N/A Upstream (East Tributary) Channelized Farm Drain Substantial No Flow Dry N/A *Flow Regime categories are defined as Substanial = Surface Flow >0.5 L/sec; Minimal = Surface Flow <0.5 L/Sec

14 July Channel and Riparian Characteristics Channel and riparian characteristics are summarized below in Tables B and C. Site #1 downstream, Site #1 upstream, and Site #2 downstream can be characterized as Defined Natural Channels, although in reality these segments were likely dug historically to provide farm drainage. All segments of Site #2 upstream, Site #3 downstream, and Site #3 upstream can be characterized as Channelized Farm Drains, which were likely dug historically to provide drainage for the adjacent farm fields. Bankfull widths are relatively wide throughout the Site, which likely results from historic plowing that largely eliminated the banks, creating broad and shallow slopes to the channels. The low flow channels throughout the system are much more narrow (approximately 30 cm to 50 cm), which reflects actual flow volumes to a greater degree than the bankfull widths. Site #1 downstream flows through a ravine where bank undercutting and other signs of erosion were observed. The substrate in this area is clay. Site #3 upstream (east tributary) flows within a narrow Deciduous Hedgerow, and the substrate in this area is exposed and consists of sand and woody debris. Throughout all other segments the substrate is underlain with silt but is dominated by thick grass growth, with cattail stands in some areas. The ravine surrounding Site #1 downstream includes a relatively narrow band of riparian forest cover, beyond which are manicured lawns associated with the adjacent developed residential properties. The right bank of Site #1 upstream and Site #2 downstream consists of manicured lawn associated with the adjacent developed residential home, whereas the left bank consists of Fallow Agricultural Fields (Graminoid Meadow). The riparian vegetation throughout all segments of Site #2 upstream, Site #3 downstream, and Site #3 upstream is dominated by Fallow Agricultural Fields (Graminoid Meadow).

15 TABLE B: CHANNEL MEASUREMENTS SITE SEGMENT FEATURE TYPE BANKFULL WIDTH (m) CHANNEL DEPTH (mm) SUBSTRATE FEATURE ROUGHNESS** CONSTRICTIONS Site #1 - River Road Site #2 - Field Drainage Confluence Downstream Defined Natural Channel Clay Minimal Upstream Defined Natural Channel Silt/Grass Extreme Downstream Defined Natural Channel Grass Extreme Upstream (South Tributary) Channelized Farm Drain Cattails/Grass Extreme Upstream (East Tributary) Channelized Farm Drain Grass/Silt Extreme Downstream Channelized Farm Drain Silt/Grass Extreme 120 cm CSP Culvert Under River Road Earth Berm Site #3 - Farm Drainage Upstream (South Tributary) Channelized Farm Drain Cattails/Grass Extreme 90 cm CSP Culvert Under Old Farm Path Upstream (East Channelized Farm Drain Sand/Woody Debris Moderate Tributary) **Feature Roughness categories are defined by OSAP Module 4.10 as; Minimal = Less than 10% of the areal coverage of the channel substrates contains materials that diffuse flows; Moderate = 10-40% of the areal coverage of the channel substrates contains materials that diffuse flows; High = 40-60% of the areal coverage of the channel substrates contains materials that diffuse flows; Extreme = More than 60% of the areal coverage of the channel substrates contains materials that diffuse flows.

16 SITE Site #1 - River Road Site #2 - Field Drainage Confluence TABLE C: RIPARIAN CLASSIFICATION SEGMENT FEATURE TYPE LEFT BANK* RIGHT BANK* m m m m m m Downstream Defined Natural Channel Forest Forest Lawn Forest Forest Lawn Upstream Defined Natural Channel Meadow Meadow Meadow Lawn Lawn Lawn Downstream Defined Natural Channel Meadow Meadow Meadow Lawn Lawn Lawn Upstream (South Tributary) Channelized Farm Drain Meadow Meadow Meadow Meadow Meadow Meadow Upstream (East Tributary) Channelized Farm Drain Meadow Meadow Meadow Meadow Meadow Meadow Downstream Channelized Farm Drain Meadow Meadow Meadow Meadow Meadow Meadow Site #3 - Farm Drainage Upstream (South Tributary) Channelized Farm Drain Meadow Meadow Meadow Meadow Meadow Meadow Upstream (East Tributary) *Left and right bank are facing upstream Channelized Farm Drain Meadow Meadow Meadow Meadow Meadow Meadow

17 July Fish Community and Fish Habitat Water levels throughout May and June were too shallow to allow the Site to be sampled using a backpack electrofisher (Stanfield 2013). Instead, on May 23 rd a dip net was used to sample areas of standing water throughout the Site. No fish were captured during dip netting, and no fish were observed visually during any of the sampling events. As noted above in Section 3.2, the hydro-period throughout the majority of the Site is very limited, with shallow water depths observed in all segments by late-spring (May). The limited hydro-period, coupled with the fact that the majority of the segments are overgrown with terrestrial vegetation (e.g. grasses) for most of the spring and summer, likely limits the functionality of the Drainage Features to provide fish habitat. No evidence of direct fish habitat was noted, and the Drainage Features likely only provide indirect fish habitat in the form of water and nutrient contributions to downstream fish habitat areas. 3.5 Amphibian Habitat Table D summarizes frog call survey results. As noted in Table D, no amphibian breeding activity was documented within the Site. Spring Peepers and Wood Frogs were heard calling in the distance east and southeast of the Site on April 23 rd and May 21 st. American Woodcocks were also observed calling and displaying above Site #2 and #3 on May 21 st. Observations of frogs calling in nearby areas on the same nights that the Drainage Features were surveyed suggests that the absence of amphibian activity within the Drainage Features was not due to poor survey conditions, but is likely due to the limited water levels and generally poor habitat quality (as described above).

18 AMPHIBIAN CALL ACTIVITY SITE SEGMENT FEATURE TYPE April 23 May 21 June 15 Site #1 - River Road Site #2 - Field Drainage Confluence Site #3 - Farm Drainage TABLE D: AMPHIBIAN SURVEY RESULTS Downstream Defined Natural Channel None Spring Peepers Heard in the Distance Southeast of the Site None Upstream Defined Natural Channel None None None Downstream Defined Natural Channel None American Woodcock Calling and Display Flights None Upstream (South American Woodcock Calling and Channelized Farm Drain None Tributary) Display Flights None Upstream (East American Woodcock Calling and Channelized Farm Drain None Tributary) Display Flights None Downstream Channelized Farm Drain None American Woodcock Calling and Display Flights None Upstream (South American Woodcock Calling and Channelized Farm Drain None Tributary) Display Flights None Wood Frogs/Spring Peepers Heard Upstream (East American Woodcock Calling and Channelized Farm Drain Calling in Distance East of Site Tributary) Display Flights Boundary None

19 July Summary of Habitat Quality As noted above, the Drainage Features convey substantial flows during the spring freshet (March), but flows decline sharply by late spring (May), such that the majority of the system only features shallow standing water. By mid-summer (July), the majority of the Site was dry. The channel banks are poorly defined, which likely results from historic plowing when the Site was farmed. The dominant substrate condition throughout the Site is silt with dense growth of terrestrial grasses. The riparian cover includes some areas of lawn surrounding Site #1 downstream, Site #1 upstream and Site #2 downstream, as well as a narrow band of riparian forest surrounding Site #1 downstream. However, overall the dominant riparian vegetation throughout the Site is Fallow Agricultural Fields (Graminoid Meadow). No evidence of direct fish habitat was noted anywhere within the Drainage Features, and amphibian survey results indicated no evidence of amphibian breeding activity within the Site. Taken together, these observations suggest that the Drainage Features provide low quality and intermittent aquatic habitat with no direct fish habitat, no amphibian breeding habitat, and very limited hydro-period.

20 July POTENTIAL DEVELOPMENT IMPACTS The Drainage Features will be decommissioned as part of the development of the residential subdivision at 879 River Road. As noted above, the Drainage Features do not provide any direct fish habitat and no evidence of amphibian breeding was noted. There are therefore no significant impacts to fish or amphibian habitat anticipated. Due to the fact that the Drainage Features provide low quality, intermittent aquatic habitat, removal of the features themselves would not be considered a significant impact. Therefore, any potential impacts associated with the removal of the Drainage Features would be limited to potential impacts on downstream areas. The primary effect that the removal of the Drainage Features may have on downstream areas would be a reduction in the flow of water and nutrients to downstream areas. Where feasible, management and mitigation efforts should focus on maintaining water and nutrient flows to downstream areas. 5.0 CLASSIFICATION The Classification Criteria for Headwaters Drainage Assessments is provided by TRCA (2014). Refer to TRCA (2014) for further detail regarding the Classification Criteria. The Classification Criteria results for the Drainage Features within the Site are as follows: Hydrological Classification: Contributing Function Ephemeral. TRCA definition: Provides ephemeral flow or water storage functions during and (for a short time) after spring freshet and following large rain events only. These features are typically dry or surface-damp by mid-may. Riparian Classification: Valued Function. TRCA definition: Any of the riparian corridor categories (0-1.5 m, m, or m on either side of the feature) is dominated by meadow and there are no important riparian functions. As noted above, the dominant riparian vegetation is Fallow Agricultural Fields (Graminoid Meadow). Fish and Fish Habitat Classification: Contributing Function. TRCA definition: Contributing fish habitat. Transport of allochthonous materials (detritus, insects, etc.) to downstream fish-bearing reaches provides sources of food. Terrestrial Habitat Classification: Limited Functions. TRCA definition: No terrestrial habitat present (e.g. no riparian connection between adjacent forest or wetland features). Following TRCA (2014) guidelines, Drainage Features with Contributing or Valued Hydrology, no Important or Valued Fish Habitat, no Important or Valued Terrestrial Habitat, and no Important Riparian Vegetation require implementation of mitigation measures to address the potential reduction in downstream nutrient and water inputs that may result from the decommission of the Drainage Features.

21 July MANAGEMENT RECOMMENDATIONS - MITIGATION 6.1 Flow Mitigation As noted above, the development of the 879 River Road Site will include decommissioning of the Drainage Features. Per the Classification Criteria discussed above in Section 5.0, TRCA (2014) guidelines recommend implementation of mitigation measures. The following flow mitigation options provided by TRCA (2014) have been discussed with the project stormwater engineer and have been determined to be potentially feasible for the 879 River Road development: Replicate on-site flow and outlet flows at the top end of system to maintain feature functions with vegetated swales, bioswales, etc. If catchment drainage has been previously removed due to diversion of stormwater flows, restore lost functions through enhanced lot level controls (i.e. restore original catchment using clean roof drainage). 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 Conservation Authority Water Management Guidelines for details). Where feasible, the stormwater management plan for the development of the 879 River Road Site should incorporate these mitigation measures in order to address the potential loss of nutrient and water inputs to downstream areas. 6.2 Construction Stage Mitigation Section 4.4 of the Combined EIS and TCR (MES 2018) describes mitigation measures for wildlife during construction. Refer to the Combined EIS and TCR for additional detail regarding construction stage mitigation. In addition to the mitigation measures described in the Combined EIS and TCR, it is recommended that future decommissioning of the Drainage Features should be completed during the middle to late summer, when the features are likely to be dry. This will prevent the need to dewater the Drainage Features, and will reduce the likelihood that wildlife may be impacted by channel decommissioning. Due to the absence of fish and amphibians, a fish and wildlife salvage operation during in-water work is not likely to be required, provided that work is completed in the dry.

22 July DETERMINATION The Drainage Features will be decommissioned as part of the development of the residential subdivision at 879 River Road. As noted above, the Drainage Features do not provide any direct fish habitat and no evidence of amphibian breeding was noted. There are therefore no significant impacts to fish or amphibian habitat anticipated. Due to the fact that the Drainage Features provide low quality, intermittent aquatic habitat, removal of the features themselves would not be considered a significant impact. Therefore, any potential impacts associated with the removal of the Drainage Features would be limited to potential impacts on downstream areas. The primary effect that the removal of the Drainage Features may have on downstream areas would be a reduction in the flow of water and nutrients to downstream areas. Mitigation options have been identified to address potential impacts to downstream areas. Provided that the mitigation and management measures are implemented appropriately, there are no significant negative impacts on the natural features and functions anticipated as a result of the planned removal of the Drainage Features.

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24 July REFERENCES City of Ottawa (2014) Natural Heritage System Overlay (West). Official Plan Schedule L3. City of Ottawa (2015) Protocol for Wildlife Protection During Construction. City of Ottawa (2018) Geo-Ottawa Municipal Mapping Site. Retrieved June 18 th, 2018 at < Konze, K. and McLaren, M. (1998) Wildlife Monitoring Programs and Inventory Techniques for Ontario Marsh Monitoring Method. NEST Technical Manual TM-009. McKinley Environmental Solutions (MES) (2018) 879 River Road Development Combined Environmental Impact Statement and Tree Conservation Report. Stanfield, L., Giudice, L.D., Bearss, E., and D. Morodvanschi (2013) Ontario Stream Assessment Protocol (OSAP) Section 4: Module 10 Assessing Headwater Drainage Features. Stanfield, L. (2013) Ontario Stream Assessment Protocol (OSAP) Section 3: Module 1 Single Pass Electrofishing Survey. Toronto and Region Conservation Authority (TRCA) (2014) Evaluation, Classification and Management of Headwater Drainage Features Guideline.

25 July APPENDIX A SITE PHOTOGRAPHS

26 July Photograph 1: Site #1 downstream, facing upstream (March 30 th, 2018). Photograph 2: 120 cm CSP culvert under River Road, facing upstream (March 30 th, 2018).

27 July Photograph 3: Looking south at the eastern roadside ditch along River Road. Note that the roadside ditch is entirely dry, even during the early spring melt (March 30 th, 2018). Photograph 4: Site #1 upstream, facing upstream (March 30 th, 2018).

28 July Photograph 5: Site #2 downstream, facing upstream (March 30 th, 2018). Photograph 6: Earth Berm restricting flow at the confluence of Site #2 (March 30 th, 2018).

29 July Photograph 7: Site #2 upstream (south tributary), facing upstream (March 30 th, 2018). Photograph 8: Site #2 upstream (east tributary), facing upstream (March 30 th, 2018).

30 July Photograph 9: Site #3 downstream, facing upstream. 90 cm CSP culvert under old farm path shown (March 30 th, 2018). Photograph 10: Site #3 upstream (south tributary), facing upstream (March 30 th, 2018).

31 July Photograph 11: Site #3 upstream (east tributary), facing upstream (March 30 th, 2018). Photograph 12: Site #1 downstream, facing upstream (May 23 rd, 2018).

32 July Photograph 13: Site #1 upstream, facing upstream (May 23 rd, 2018). Photograph 14: Site #2 downstream, facing upstream (May 23 rd, 2018).

33 July Photograph 15: Site #2 upstream (south tributary), facing upstream (May 23 rd, 2018). Photograph 16: Site #2 upstream (east tributary), facing upstream (May 23 rd, 2018).

34 July Photograph 17: Site #3 downstream, facing upstream. 90 cm CSP culvert under old farm path shown (May 23 rd, 2018). Photograph 18: Site #3 upstream (south tributary), facing upstream (May 23 rd, 2018).

35 July Photograph 19: Site #3 upstream (east tributary), facing upstream (May 23 rd, 2018). Photograph 20: Site #1 downstream, facing upstream (July 3 rd, 2018).

36 July Photograph 21: Site #1 upstream, facing upstream (July 3 rd, 2018). Photograph 22: Site #2 downstream, facing upstream (July 3 rd, 2018).

37 July Photograph 23: Site #2 upstream (south tributary), facing upstream (July 3 rd, 2018). Photograph 24: Site #2 upstream (east tributary), facing upstream (July 3 rd, 2018).

38 July Photograph 25: Site #3 downstream, facing upstream (July 3 rd, 2018). Photograph 26: Site #3 upstream (south tributary), facing upstream (July 3 rd, 2018).

39 July Photograph 27: Site #3 upstream (east tributary), facing upstream (July 3 rd, 2018).