ASSESSMENT OF ADEQUACY OF PUBLIC SERVICES BRIGIL 460 ST. LAURENT BOULEVARD

Transcription

1 ASSESSMENT OF ADEQUACY OF PUBLIC SERVICES FOR BRIGIL 460 ST. LAURENT BOULEVARD CITY OF OTTAWA PROJECT NO.: MAY 2012 REV 1 DSEL

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3 ASSESSMENT OF ADEQUACY OF PUBLIC SERVICES FOR BRIGIL 460 ST. LAURENT BOULEVARD MAY 2012 REV 1 TABLE OF CONTENTS 1.0 INTRODUCTION Existing Conditions Required Permits / Approvals Pre-consultation GUIDELINES, PREVIOUS STUDIES, AND REPORTS WATER SUPPLY SERVICING Existing Water Supply Services Water Supply Servicing Design Water Supply Conclusion WASTEWATER SERVICING Existing Wastewater Services Wastewater Design Wastewater Servicing Conclusions STORMWATER MANAGEMENT Existing Stormwater Services Post-development Stormwater Management Targets Stormwater Management System Stormwater Servicing Conclusions UTILITIES CONCLUSION AND RECOMMENDATIONS DAVID SCHAEFFER ENGINEERING LTD. PAGE I DSEL

4 ASSESSMENT OF ADEQUACY OF PUBLIC SERVICES BRIGIL 460 ST. LAURENT BOULEVARD MAY 2012 REV 1 FIGURES Figure 1 Site Location TABLES Table 1 Table 2 Table 3 Table 4 Table 5 Table 6 Table 7 Fire Hydrant Testing Results Water Supply Design Criteria Water Demand and Boundary Conditions Wastewater Design Criteria Anticipated Wastewater Conditions Summary of Existing Peak Storm Flow Rates Summary of Release Rates and Required Storage APPENDICES Appendix A Appendix B Appendix C Appendix D Pre-Consultation and Check List Water Supply Wastewater Collection Stormwater Management PAGE II DAVID SCHAEFFER ENGINEERING LTD. DSEL

5 ST. ST. ST. ST. ST. LAURENT LAURENT LAURENT LAURENT LAURENT BLVD BLVD BLVD BLVD BLVD COLEFORD COLEFORD COLEFORD PL PL PL 1.0 INTRODUCTION ASSESSMENT OF ADEQUACY OF PUBLIC SERVICES FOR BRIGIL 460 ST. LAURENT BOULEVARD CITY OF OTTAWA MAY 2012 REV 1 PROJECT NO.: Brigil has retained David Schaeffer Engineering Limited (DSEL) to prepare an Assessment of Adequacy of Public Services in support of their Zoning By-law Amendment (ZBLA) for 460 St. Laurent Boulevard. The subject property is located within the City of Ottawa urban boundary. As illustrated in Figure 1, the subject property is located in the southwest quadrant of the Dunbarton court and St. Laurent Boulevard intersection SUBJECT PROPERTY BRITTANY DR BRITTANY DR ST. ST. ST. ST. ST. LAURENT LAURENT LAURENT LAURENT LAURENT BLVD BLVD BLVD BLVD BLVD DUNBARTON CRT DUNBARTON CRT DUNBARTON CRT ST. ST. ST. ST. ST. LAURENT LAURENT LAURENT LAURENT LAURENT BLVD BLVD BLVD BLVD BLVD Figure 1 - Site Location DAVID SCHAEFFER ENGINEERING LTD. PAGE 1 DSEL

6 ASSESSMENT OF ADEQUACY OF PUBLIC SERVICES BRIGIL 460 ST. LAURENT BOULEVARD MAY 2012 REV 1 The site measures approximately 0.25ha and the property is currently comprised of an auto repair shop. Under the City of Ottawa Zoning By-law, the existing lands are currently designated General Mixed-Use Zone, GM F(1.5). The proposed ZBLA would allow for the development of a 15-storey residential tower abutting St. Laurent Boulevard, including ground level commercial space and underground parking. The objective of this report is to provide sufficient detail to demonstrate that the proposed re-zoning and development is supported by the existing municipal services. 1.1 Existing Conditions The subject property is part of the Alvin Heights Collector wastewater catchment area and located within the 1E municipal water pressure zone. The existing site contains a single: 1-storey structure with associated paved parking areas as illustrated by the site topographic survey in Drawings/Figures. Several services and utilities cross the site within the former St. Laurent Boulevard rightof-way. Currently the following underground municipal services are running through the site, a 300mm diameter sanitary sewer, a 675mm diameter storm sewer, a 200mm diameter watermain, and a 550mm wide hydro ductbank. In addition to the underground services, overhead hydro lines run through the west side of the property. The location of the referenced services and utilities are shown by SRP-1 in Drawings/Figures. Municipal services as indicated below are available within the respective right-of-ways. Watermains: 406mm diameter local service located on St. Laurent Boulevard 203mm diameter local service located on Dunbarton Court Sanitary and Storm Sewers: 300mm diameter local sanitary service located on Dunbarton Court 675mm diameter local storm service located on Dunbarton Court SPL Consultants completed a geotechnical investigation of the subject property in December of Bedrock was observed within a range of m of the existing ground surface. Due to this close proximity of rock to the surface, the location and depth of services may require removal of bedrock. Figure 2 in Drawings/Figures illustrates the location of boreholes and their respective bedrock depths. PAGE 2 DSEL DAVID SCHAEFFER ENGINEERING LTD.

7 ASSESSMENT OF ADEQUACY OF PUBLIC SERVICES BRIGIL 460 ST. LAURENT BOULEVARD MAY 2012 REV Required Permits / Approvals Development of the site would be subject to the City of Ottawa planning and development approvals process. The City of Ottawa must approve detailed engineering design drawings and reports prepared to support the proposed development plan, prior to the issuance of site plan control approval for development. 1.3 Pre-consultation Pre-consultation with relevant parties, including the City of Ottawa and Rideau Valley Conservation Authority, was conducted via for the proposed development. Preconsultation correspondence, along with the servicing guidelines checklist, is located in Appendix A. DAVID SCHAEFFER ENGINEERING LTD. PAGE 3 DSEL

8 ASSESSMENT OF ADEQUACY OF PUBLIC SERVICES BRIGIL 460 ST. LAURENT BOULEVARD MAY 2012 REV GUIDELINES, PREVIOUS STUDIES, AND REPORTS The following studies were utilized in the preparation of this report. Ottawa Sewer Design Guidelines, City of Ottawa, November (City Standards) o Technical Bulletin ISD City of Ottawa, December 15, (ISD ) o Technical Bulletin ISD City of Ottawa, January 31, (ISD ) Ottawa Design Guidelines Water Distribution City of Ottawa, July 2010 (Water Supply Guidelines) Stormwater Planning and Design Manual, Ministry of the Environment, March (SWMP Design Manual) Ontario Building Code Compendium Ministry of Municipal Affairs and Housing Building Development Branch, January 1, 2010 Update (OBC) Geotechnical Investigation SPL Consultants Ltd. December 2011, Project Number: PAGE 4 DSEL DAVID SCHAEFFER ENGINEERING LTD.

9 ASSESSMENT OF ADEQUACY OF PUBLIC SERVICES BRIGIL 460 ST. LAURENT BOULEVARD MAY 2012 REV WATER SUPPLY SERVICING 3.1 Existing Water Supply Services The subject property lies within the City of Ottawa 1E pressure zone. A local 203mm diameter watermain exists within the Dunbarton right-of-way along with a 406mm diameter watermain located within St. Laurent. In addition to these services, a 203mm diameter watermain exists within the former St. Laurent Boulevard right-of-way crossing the site as shown by SRP-1 in Drawings/Figures; this service has been identified by the city as being superfluous and will be abandoned during development of the site. The City of Ottawa Drinking Water Services branch completed fire hydrant testing in Table 1 summarizes the results of the hydrant testing. Hydrant ID is the closest representation to the subject property and is fed by the existing 406mm watermain within St. Laurent Boulevard. Correspondence with the Drinking Water Services branch is located in Appendix B. Flow Hydrant Residual Hydrant Table 1 Fire Hydrant Testing Results Static Pressure (kpa) Dynamic Pressure (kpa) Pitot Pressure (kpa) Measured Flow (L/min) Available Fire Flow at 140kPa (L/min) Water Supply Servicing Design It is anticipated that the development will be serviced via a private service connection to the existing local 203mm diameter watermain located within the Dunbarton Court rightof-way. It is proposed to remove the existing 203mm diameter watermain running through the site to remove an undesirable dead end connection and to provide greater area for development. Table 2 summarizes the Water Supply Guidelines employed in the preparation of the water demand estimate. DAVID SCHAEFFER ENGINEERING LTD. PAGE 5 DSEL

10 ASSESSMENT OF ADEQUACY OF PUBLIC SERVICES BRIGIL 460 ST. LAURENT BOULEVARD MAY 2012 REV 1 Table 2 Water Supply Design Criteria Design Parameter Value Residential Average Apartment Demand 1.8 person/unit Residential Daily Average 350 L/person/d Commercial floor space 2.5 L/m 2 /d Commercial Maximum Daily Demand 1.5 x Average Daily Commercial Maximum Hourly 1.8 x Maximum Daily Minimum Watermain Size 150mm diameter Minimum Depth of Cover 2.4m from top of watermain to finished grade During Peak Hourly Demand desired operating 350kPa and 480kPa pressure is within During normal operating conditions pressure must 275kPa not drop below During fire flow operating pressure must not drop 140kPa below * Residential Max. Daily and Max. Hourly peaking factors per MOE Guidelines for Drinking-Water Systems Table 3-3 for 0 to 500 persons. ** Table updated to reflect ISD Table 3 summarizes the anticipated water demand and boundary conditions for the proposed development based on the Water Supply Guidelines. Table 3 Water Demand and Boundary Conditions Design Parameter Anticipated Demand 1 (L/min) Boundary Condition 2 (m H 2 O / kpa) Average Daily Demand 72.5 Max Day + Fire Flow ,000= 9,257.6 Peak Hour ) Water demand calculation per Water Supply Guidelines. See Appendix B for detailed calculations. 2) Boundary conditions supplied by the City of Ottawa. Assumed ground elevation 00.0m. See Appendix B. Section of the City Design guidelines for water distribution provides guidance for determining the method for estimating Fire Demand. As indicated, the requirements for levels of fire protection on private property are covered in the Ontario Building code. Section of the OBC addresses the installation of water service pipes and fire service mains. Part 3 of the OBC outlines the requirement for Fire Protection, Occupant Safety, and Accessibility; and sub-section A provides the provisions for firefighting. Based on trained personnel responding to the emergency, and water supply being delivered through a municipal system, the required minimum provision for water supply flow rates shall not be less than 2,700L/min or greater than 9000L/min (OBC Section A , Table 2). Therefore, a conservative estimate for the required supply is 9000L/min. A certified fire protection system specialist shall be employed to design the building fire suppression system(s) and confirm the actual fire flow demand. PAGE 6 DSEL DAVID SCHAEFFER ENGINEERING LTD.

11 ASSESSMENT OF ADEQUACY OF PUBLIC SERVICES BRIGIL 460 ST. LAURENT BOULEVARD MAY 2012 REV 1 The City of Ottawa was contacted to obtain boundary conditions associated with the estimated water demand as indicated in Table 3. No response was received at the time of publication. Correspondence with the City has been included in Appendix A. 3.3 Water Supply Conclusion Anticipated water demand under proposed conditions was submitted to the City of Ottawa for establishing boundary conditions. As demonstrated by Tables 1 and 3 sufficient supply appears to be available from the municipal watermain services. As demonstrated in Table 3, the recommended pressure range is respected during Maximum Day plus Fire Flow as well as Peak Hour demands. DAVID SCHAEFFER ENGINEERING LTD. PAGE 7 DSEL

12 ASSESSMENT OF ADEQUACY OF PUBLIC SERVICES BRIGIL 460 ST. LAURENT BOULEVARD MAY 2012 REV WASTEWATER SERVICING 4.1 Existing Wastewater Services The subject property is tributary to the Alvin Heights Collector, ultimately discharging to the Ottawa Outfall Trunk sewer. An existing 300mm diameter municipal sanitary sewer exists within Dunbarton Court along with a 300mm diameter sanitary sewer located within the former St. Laurent Boulevard, across the site. Both of these local sewers convey sanitary flow north along St. Laurent Boulevard to London Terrace then to the Alvin Heights Collector. 4.2 Wastewater Design It is proposed that the sanitary sewer that currently runs through the site be relocated to allow for increased area for development. The sanitary sewer would be extended from the current alignment behind 500 St. Laurent to Dunbarton Court. The sewer would then be directed, within the Dunbarton right-of-way, back towards St. Laurent Boulevard, to allow reconnection to the existing sewer within the Dunbarton-St. Laurent intersection. The proposed realignment is shown by SRP-1 in Drawings/Figures. It is anticipated that the future development will outlet to the realigned 300mm diameter municipal sanitary sewer to be located within the Dunbarton right-of-way. Table 4 summarizes the City Standards employed in the design of the proposed wastewater sewer system. Table 4 Wastewater Design Criteria Design Parameter Value Commercial Floor Space 5 L/m 2 /d Residential Average Apartment Demand 1.8 person/unit Residential Daily Average 350 L/person/d Peaking Factor Harmon s Peaking Factor. Max 4.0, Min 2.0 Commercial Floor Space 50,000 L/gross ha/d Office Space 75 L/9.3m 2 /d Infiltration and Inflow Allowance 0.28L/s/ha Sanitary sewers are to be sized employing the Manning s Equation Q AR S n Minimum Sewer Size 200mm diameter Minimum Manning s n Minimum Depth of Cover 2.5m from crown of sewer to grade Minimum Full Flowing Velocity 0.6m/s Maximum Full Flowing Velocity 3.0m/s Extracted from Sections 4 and 6 of the City of Ottawa Sewer Design Guidelines, November PAGE 8 DSEL DAVID SCHAEFFER ENGINEERING LTD.

13 ASSESSMENT OF ADEQUACY OF PUBLIC SERVICES BRIGIL 460 ST. LAURENT BOULEVARD MAY 2012 REV 1 Table 5 summarizes the anticipated wastewater flow for the subject property. See Appendix C for associated calculations. Table 5 Anticipated Wastewater Conditions Design Parameter Total Flow (L/s) Estimated Average Dry Weather Flow Rate 1.29 Estimated Peak Dry Weather Flow Rate 4.90 Estimated Peak Wet Weather Flow Rate 4.97 The anticipated peak wastewater flow generated from the proposed development has been estimated to be 4.97L/s, including a 0.28L/s/ha allowance for extraneous flow. Refer to Appendix C for associated calculations. 4.3 Wastewater Servicing Conclusions Based on consultation with the City of Ottawa, capacity of local municipal sanitary sewers is not a concern for the proposed development. The proposed realignment is not anticipated to result in any significant impact on the operation of the municipal wastewater system. Any proposed wastewater design must conform to the relevant City of Ottawa Sewer Design Guidelines. DAVID SCHAEFFER ENGINEERING LTD. PAGE 9 DSEL

14 ASSESSMENT OF ADEQUACY OF PUBLIC SERVICES BRIGIL 460 ST. LAURENT BOULEVARD MAY 2012 REV STORMWATER MANAGEMENT 5.1 Existing Stormwater Services Stormwater runoff from the subject property is tributary to the City of Ottawa storm sewer system located within the Ottawa Central sub-watershed. As such, approvals for proposed development within this area are under the approval authority of the City of Ottawa. Flows that influence the watershed in which the subject property is located are further reviewed by the principal authority. The subject property is located within the Rideau River watershed, and is therefore subject to review by the Rideau Valley Conservation Authority (RVCA). Consultation with the RVCA is located in Appendix A. Runoff from the existing site is directed to the existing 675mm municipal storm sewers located within the former St. Laurent Boulevard right-of-way crossing the site. Stormwater is conveyed north along St. Laurent Boulevard, outletting approximately 500m north of the site to an unnamed watercourse, then ultimately discharging to the Ottawa River. The estimated pre-development peak flows for the historical 2, 5, and 100-year storm events are summarized in Table 6, detailed calculations are located in Appendix D: Table 6 Summary of Existing Peak Storm Flow Rates City of Ottawa Design Storm Estimated Peak Flow Rate (L/s) 2-year year year Post-development Stormwater Management Targets Stormwater management requirements for the proposed development are based on consultation with the City of Ottawa, RVCA and the relevant Sewer Design Guidelines. It has been established that the following criteria apply: An Allowable release rate has been calculated based on a Rational Method Runoff Coefficient of 0.5 and employing the City of Ottawa IDF parameters for a 5-year storm with a time of concentration equal to 20 minutes. Analysis of the site determined the more restrictive 0.5 value to be appropriate. All storms up to and including the City of Ottawa 100-year design event are to be attenuated on site. PAGE 10 DSEL DAVID SCHAEFFER ENGINEERING LTD.

15 ASSESSMENT OF ADEQUACY OF PUBLIC SERVICES BRIGIL 460 ST. LAURENT BOULEVARD MAY 2012 REV 1 Due to the proximity of the development to a natural watercourse, Best Management Practices should be implemented to reduce Total Suspended Solids (TSS) entering the receiving watercourse. See correspondence with the City of Ottawa and RVCA in Appendix A. 5.3 Stormwater Management System It is proposed that the storm sewer that currently runs through the site be relocated to allow for increased area for development. The storm sewer would be extended from the current alignment behind 500 St. Laurent to Dunbarton Court. The sewer would then be directed, within the Dunbarton right-of-way, back to towards St. Laurent Boulevard, to allow reconnection to the existing sewer within the Dunbarton-St. Laurent intersection. The proposed realignment is shown by SRP-1 in Drawings/Figures. It is anticipated that the future development will outlet to the realigned 675mm diameter municipal storm sewer to be located within the Dunbarton right-of-way. In order to achieve the allowable post-development stormwater runoff release rate established in Section 5.2 above, the proposed development may employ a combination of rooftop flow attenuation in combination with subsurface and surface storage. As discussed with the Rideau Valley Conservation Authority, specific quality targets are not imposed, however Best Management Practices should be implemented, including the potential direction of parking lot runoff to grassed swales, where possible, to reduce TSS and promote filtration of runoff prior discharge to the municipal storm sewer and ultimately the receiving watercourse. It is also recommended that regular maintenance of any site stormwater management system be completed. This would include annual cleaning of catchbasin/manhole sumps, and limiting the use of salt, sand and gravel in parking lots during the winter months, in addition to spring sweeping of parking areas to assist in reducing the amount of suspended solids that enter the storm sewer system. Table 7 summarizes the anticipated on site storage required to meet established target release rates. To provide an accurate estimate of required storage volume it is anticipated that a portion of the site will be released unattenuated due to potential grading constraints; this is reflected in Table 7. Flow from these areas will be compensated for in areas with controls. DAVID SCHAEFFER ENGINEERING LTD. PAGE 11 DSEL

16 ASSESSMENT OF ADEQUACY OF PUBLIC SERVICES BRIGIL 460 ST. LAURENT BOULEVARD MAY 2012 REV 1 Table Notes: Table 7 Summary of Release Rates and Required Storage 5-Year Release Rate 5-Year Storage 100-Year Release Rate 100-Year Storage Control Area (L/s) (m 3 ) (L/s) (m 3 ) Unattenuated Areas Attenuated Areas Total Release rate calculated using the critical time of concentration as established by City of Ottawa pre-consultation and Sewer Design Guidelines. 2. Total release rate calculated using attenuated areas + unattenuated areas. In order to attenuate stormwater runoff from the 100-year storm to the attenuated 5-year release rate of 24.9L/s, approximately 86m 3 of storage will be required. Detailed calculations are provided in Appendix D. 5.4 Stormwater Servicing Conclusions Post development stormwater runoff will be restricted to the allowable target for storm events up to and including the 1:100 year historical storm event in accordance with the City of Ottawa Sewer Design Guidelines. The maximum attenuated post-development release rate has been calculated to be 24.9L/s based on consultation with the City of Ottawa. Consultation with the RVCA determined that Best Management Practices should be implemented for all stormwater runoff due to the proximity of the site to the municipal storm sewer outlet. Any proposed stormwater design is required to conform to all relevant City guidelines and policies for approval. PAGE 12 DSEL DAVID SCHAEFFER ENGINEERING LTD.

17 ASSESSMENT OF ADEQUACY OF PUBLIC SERVICES BRIGIL 460 ST. LAURENT BOULEVARD MAY 2012 REV UTILITIES Currently the site has access to Hydro, Gas, Bell and Rogers within the municipal rightof-ways. Hydro Ottawa has been contacted to establish appropriate development setbacks and easements requirements associated with the existing overhead pole line and underground duct bank crossing the site. Utility servicing will need to be coordinated with the individual utility companies prior to site development. 7.0 CONCLUSION AND RECOMMENDATIONS Brigil is proposing the construction of 15-Storey residential tower at 460 St. Laurent Boulevard. DSEL was retained to prepare an Assessment of Adequacy of Public Services in support of the associated Zoning By-law Amendment (ZBLA). The preceding report outlines the following: The anticipated water demand under proposed conditions was submitted to the City of Ottawa for establishing boundary conditions. Fire flow data suggests that sufficient water capacity is available to support the development. Consultation with the City indicated that the existing municipal wastewater infrastructure would have sufficient capacity to support the proposed development. The post-development release rate has been calculated to be 24.9L/s based on consultation with the City of Ottawa. Consultation with the RVCA determined that Best management Practices for all stormwater runoff should be implemented due to the proximity to the storm outlet. DAVID SCHAEFFER ENGINEERING LTD. PAGE 13 DSEL

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19 APPENDIX A Pre-Consultation

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21 DEVELOPMENT SERVICING STUDY CHECKLIST /05/ General Content Executive Summary (for larger reports only). N/A Date and revision number of the report. Report Cover Sheet Location map and plan showing municipal address, boundary, and layout of proposed development. Drawings/Figures Plan showing the site and location of all existing services. Figure 1 Development statistics, land use, density, adherence to zoning and official plan, and reference to applicable subwatershed and watershed plans that provide context to applicable subwatershed and watershed plans that provide context Section 1.0 to which individual developments must adhere. Summary of Pre-consultation Meetings with City and other approval agencies. Section 1.3 Reference and confirm conformance to higher level studies and reports (Master Servicing Studies, Environmental Assessments, Community Design Plans), or in the case where it is not in conformance, the proponent must provide Section 2.1 justification and develop a defendable design criteria. Statement of objectives and servicing criteria. Section 1.0 Identification of existing and proposed infrastructure available in the immediate area. Sections 3.1, 4.1, 5.1 Identification of Environmentally Significant Areas, watercourses and Municipal Drains potentially impacted by the proposed development (Reference can be N/A made to the Natural Heritage Studies, if available). Concept level master grading plan to confirm existing and proposed grades in the development. This is required to confirm the feasibility of proposed stormwater management and drainage, soil removal and fill constraints, and N/A potential impacts to neighbouring properties. This is also required to confirm that the proposed grading will not impede existing major system flow paths. Identification of potential impacts of proposed piped services on private services (such as wells and septic fields on adjacent lands) and mitigation N/A required to address potential impacts. Proposed phasing of the development, if applicable. N/A Reference to geotechnical studies and recommendations concerning servicing. Section 1.4 All preliminary and formal site plan submissions should have the following information: -Metric scale -North arrow (including construction North) -Key plan -Name and contact information of applicant and property owner -Property limits including bearings and dimensions -Existing and proposed structures and parking areas -Easements, road widening and rights-of-way -Adjacent street names Drawings/Figures 4.2 Development Servicing Report: Water Confirm consistency with Master Servicing Study, if available N/A Availability of public infrastructure to service proposed development Section 3.1 Identification of system constraints Section 3.1 Identify boundary conditions Section 3.1, 3.2 Confirmation of adequate domestic supply and pressure Section 3.3 DSEL *Extracted from the City of Ottawa-Servicing Study Guidelines for Development Applications i

22 DEVELOPMENT SERVICING STUDY CHECKLIST Confirmation of adequate fire flow protection and confirmation that fire flow is calculated as per the Fire Underwriter s Survey. Output should show available Section 3.2 fire flow at locations throughout the development. Provide a check of high pressures. If pressure is found to be high, an assessment is required to confirm the application of pressure reducing valves. N/A Definition of phasing constraints. Hydraulic modeling is required to confirm servicing for all defined phases of the project including the ultimate design N/A Address reliability requirements such as appropriate location of shut-off valves N/A Check on the necessity of a pressure zone boundary modification N/A Reference to water supply analysis to show that major infrastructure is capable of delivering sufficient water for the proposed land use. This includes data that shows that the expected demands under average day, peak hour and fire flow Section 3.2, 3.3 conditions provide water within the required pressure range Description of the proposed water distribution network, including locations of proposed connections to the existing system, provisions for necessary looping, and appurtenances (valves, pressure reducing valves, valve chambers, and fire N/A hydrants) including special metering provisions. Description of off-site required feedermains, booster pumping stations, and other water infrastructure that will be ultimately required to service proposed development, including financing, interim facilities, and timing of N/A implementation. Confirmation that water demands are calculated based on the City of Ottawa Design Guidelines. Section 3.2 Provision of a model schematic showing the boundary conditions locations, streets, parcels, and building locations for reference. N/A 4.3 Development Servicing Report: Wastewater Summary of proposed design criteria (Note: Wet-weather flow criteria should not deviate from the City of Ottawa Sewer Design Guidelines. Monitored flow data from relatively new infrastructure cannot be used to justify capacity requirements for proposed infrastructure). Confirm consistency with Master Servicing Study and/or justifications for deviations. Consideration of local conditions that may contribute to extraneous flows that are higher than the recommended flows in the guidelines. This includes groundwater and soil conditions, and age and condition of sewers. Description of existing sanitary sewer available for discharge of wastewater from proposed development. Verify available capacity in downstream sanitary sewer and/or identification of upgrades necessary to service the proposed development. (Reference can be made to previously completed Master Servicing Study if applicable) Calculations related to dry-weather and wet-weather flow rates from the development in standard MOE sanitary sewer design table (Appendix C ) format. Description of proposed sewer network including sewers, pumping stations, and forcemains. Discussion of previously identified environmental constraints and impact on servicing (environmental constraints are related to limitations imposed on the development in order to preserve the physical condition of watercourses, vegetation, soil cover, as well as protecting against water quantity and quality). Section 4.2 N/A N/A Section 4.1 N/A Section 4.2, Appendix C Section 4.2 N/A ii *Extracted from the City of Ottawa-Servicing Study Guidelines for Development Applications DSEL

23 DEVELOPMENT SERVICING STUDY CHECKLIST Pumping stations: impacts of proposed development on existing pumping stations or requirements for new pumping station to service development. N/A Forcemain capacity in terms of operational redundancy, surge pressure and maximum flow velocity. N/A Identification and implementation of the emergency overflow from sanitary pumping stations in relation to the hydraulic grade line to protect against N/A basement flooding. Special considerations such as contamination, corrosive environment etc. N/A 4.4 Development Servicing Report: Stormwater Checklist Description of drainage outlets and downstream constraints including legality of outlets (i.e. municipal drain, right-of-way, watercourse, or private property) Section 5.1 Analysis of available capacity in existing public infrastructure. N/A A drawing showing the subject lands, its surroundings, the receiving watercourse, existing drainage patterns, and proposed drainage pattern. Drawings/Figures Water quantity control objective (e.g. controlling post-development peak flows to pre-development level for storm events ranging from the 2 or 5 year event (dependent on the receiving sewer design) to 100 year return period); if other objectives are being applied, a rationale must be included with reference to Section 5.2 hydrologic analyses of the potentially affected subwatersheds, taking into account long-term cumulative effects. Water Quality control objective (basic, normal or enhanced level of protection based on the sensitivities of the receiving watercourse) and storage 5.2,5.3 requirements. Description of the stormwater management concept with facility locations and descriptions with references and supporting information Section 5.3 Set-back from private sewage disposal systems. N/A Watercourse and hazard lands setbacks. N/A Record of pre-consultation with the Ontario Ministry of Environment and the Conservation Authority that has jurisdiction on the affected watershed. Appendix A Confirm consistency with sub-watershed and Master Servicing Study, if applicable study exists. N/A Storage requirements (complete with calculations) and conveyance capacity for minor events (1:5 year return period) and major events (1:100 year return Section 5.3 period). Identification of watercourses within the proposed development and how watercourses will be protected, or, if necessary, altered by the proposed N/A development with applicable approvals. Calculate pre and post development peak flow rates including a description of existing site conditions and proposed impervious areas and drainage Section 5.1, 5.3 catchments in comparison to existing conditions. Any proposed diversion of drainage catchment areas from one outlet to another. N/A Proposed minor and major systems including locations and sizes of stormwater trunk sewers, and stormwater management facilities. N/A If quantity control is not proposed, demonstration that downstream system has adequate capacity for the post-development flows up to and including the 100- N/A year return period storm event. Identification of potential impacts to receiving watercourses N/A Identification of municipal drains and related approval requirements. N/A DSEL *Extracted from the City of Ottawa-Servicing Study Guidelines for Development Applications iii

24 DEVELOPMENT SERVICING STUDY CHECKLIST Descriptions of how the conveyance and storage capacity will be achieved for the development. Section year flood levels and major flow routing to protect proposed development from flooding for establishing minimum building elevations (MBE) and overall N/A grading. Inclusion of hydraulic analysis including hydraulic grade line elevations. N/A Description of approach to erosion and sediment control during construction for the protection of receiving watercourse or drainage corridors. Section 6.0 Identification of floodplains proponent to obtain relevant floodplain information from the appropriate Conservation Authority. The proponent may be required to delineate floodplain elevations to the satisfaction of the N/A Conservation Authority if such information is not available or if information does not match current conditions. Identification of fill constraints related to floodplain and geotechnical investigation. N/A 4.5 Approval and Permit Requirements: Checklist Conservation Authority as the designated approval agency for modification of floodplain, potential impact on fish habitat, proposed works in or adjacent to a watercourse, cut/fill permits and Approval under Lakes and Rivers Improvement Act. The Conservation Authority is not the approval authority for the Lakes and N/A Rivers Improvement ct. Where there are Conservation Authority regulations in place, approval under the Lakes and Rivers Improvement Act is not required, except in cases of dams as defined in the Act. Application for Certificate of Approval (CofA) under the Ontario Water Resources Act. N/A Changes to Municipal Drains. N/A Other permits (National Capital Commission, Parks Canada, Public Works and Government Services Canada, Ministry of Transportation etc.) N/A 4.6 Conclusion Checklist Clearly stated conclusions and recommendations Section 8.0 Comments received from review agencies including the City of Ottawa and information on how the comments were addressed. Final sign-off from the responsible reviewing agency. All draft and final reports shall be signed and stamped by a professional Engineer registered in Ontario iv *Extracted from the City of Ottawa-Servicing Study Guidelines for Development Applications DSEL

25 Robert Freel From: Sent: To: Subject: Attachments: Matt Wingate May :17 AM 'Robert Freel' FW: 460 St-Laurent Blvd - Sewer Realignment _538_Figure-2.pdf From: Matt Wingate [mailto:mwingate@dsel.ca] Sent: Friday, January 27, :30 AM To: 'White, Joshua' Cc: 'Michel Gagnon'; 'Miguel Tremblay' Subject: RE: 460 St-Laurent Blvd - Sewer Realignment Hi Josh, We ve considered your comments concerning redirection of the storm and sanitary sewers to outlet into the existing sewers along Dunbarton. Collecting sufficient information to demonstrate the effects of storm sewer HGL on the up and down stream development would be a significant undertaking, and it also comes with the risk of an unfavourable outcome With this in mind, we ve prepared the attached alternative approach to redirecting the sewers along Dunbarton and re-connecting them to the same receiving sewers at the St Laurent Blvd intersection. Based on existing surveyed manhole invert elevations collected in the field, this would appear to improve the slopes with the sewers along this section currently crossing the site, and as such should alleviate concerns related to creating a negative HGL effect upstream. The sketch attached is a conceptual rendering of the sewer alignments only, intended for general review and comment. If this sewer realignment is acceptable to the City, we can prepare detailed design to illustrate compliance with design standards and right-of-way management requirements. Your feedback would be appreciated. The land owner is optimistic that we can find a solution to resolve the sewer encumbrances on the site, so that they can expedite development applications. Feel free to call me to discuss. Thanks Matt Wingate, P.Eng. Senior Engineer / Manager of Contract Administration 1

26 DSEL david schaeffer engineering ltd 120 Iber Road, Unit 203 Stittsville, ON K2S 1E9 phone: (613) ext 222 fax: (613) cell: (613) This , including any attachments, is for the sole use of the intended recipient(s) and may contain private, confidential, and privileged information. Any unauthorized review, use, disclosure, or distribution is prohibited. If you are not the intended recipient or if this information has been inappropriately forwarded to you, please contact the sender by reply and destroy all copies of the original. From: White, Joshua Sent: Monday, January 23, :52 PM To: Subject: 406 St. Laurant Hi Matt, To follow up on my from last week. It appears that the upstream SSO Manholes were sealed in 1998 so the upstream portion would no long be considered an SSO system. With that said your proposal still causes concern in regards the effects of the storm sewer HGL. Joshua White Project Manager, Infrastructure Approvals Development Review, Urban Services Phone: (613) ext Please consider the environment before printing this . From: White, Joshua Sent: Wednesday, January 18, :49 AM To: Subject: RE: 460 St-Laurent Blvd - Sewer Realignment Hi Matt, 2

27 I have met with Public Works and ISD to discuss this project. It appears that the area upstream was a partially separated sewer area which utilised a Sanitary Sewer Overflow (SSO), while work has gone on the rectify this situation I cannot confirm that the upstream area has been entirely separated. Two options were discussed as to how to proceed with the realignment of the sewer. Option 1: To maintain the current outlet of the sewers by installing a new length of pipe from St Laurent down Dunbarton to the intersection point of the realigned sewers (please see the attached sketch). The major advantage to this approach is that it is simply the relocation of the existing sewer and this would be able to be handled as a transfer of review. Option 2: Tying into the sewers in Dunbarton. As this proposal is changing sewer sheds and in light of the upstream system appears to be a SSO area this could have significant impacts on the surrounding community that is serviced by the Dunbarton sewer. A study would have to be prepared which would identify the flows from the upstream sewer shed (both Sanitary and Storm) and address the impacts (HGL, Capacity, etc for both san and storm) of the relocation on the upstream sewer shed and on the Dunbarton sewer both upstream and downstream of the connection. The scope of this study would have to be discussed between the yourselves, Planning and ISD. Also this may be more complicated when it comes to what approvals would be required from the Ministry of the Environment. If you would like to discuss this with me further please don t hesitate to contact me. Joshua White Project Manager, Infrastructure Approvals Development Review, Urban Services Phone: (613) ext joshua.white@ottawa.ca Please consider the environment before printing this . From: Matt Wingate [mailto:mwingate@dsel.ca] Sent: Friday, December 16, :48 PM To: Josh White (Joshua.White@ottawa.ca) Cc: 'Michel Gagnon'; 'Miguel Tremblay'; Hazlett, Benjamin Subject: 460 St-Laurent Blvd - Sewer Realignment Josh, Following up on our meeting December 7 th Attached is a sketch illustrating the proposed realignment of storm & sanitary sewers + watermain that currently cross 460 St-Laurent Blvd within a City maintenance easement. In our discussion we had agreed that the best course of action would be to present the proposed realignment to infrastructure services for their feedback. The realignment is of course critical to freeing up sufficient space to make development of a multistorey building feasible for this site. The proposed sewer realignment will direct flow in the existing storm and sanitary sewers (which service existing development south of the site) into the municipal sewers along Dunbarton Court. The extent of the storm and sanitary drainage areas that will be directed into the Dunbarton sewers can be clearly 3

28 identified from the City s sewer base mapping. We have copies of the base mapping on file, but I am sure that you have direct access to this info so I haven t copied it to this . Based on the Dunbarton Court plan & profile information available, it appears that bedrock exists at an elevation of roughly 69.5m. The proposed sewer inverts are at an elevation of +/-68.5m. Please provide your comments. Ben, Please review the proposed sewer realignment in relation to existing hydro infrastructure and provide comment. We would be interested to find out an approximate budget to relocate the existing underground hydro duct bank that crosses the property over to the west side of the proposed watermain shown. I can provide a markup to illustrate the conceptual realignment of u/g hydro if required. Miguel, I haven t copied the City planners as I assumed that these questions were oriented more towards engineering. Please feel free to forward to Alain & Bliss. Regards, Matt Wingate, P.Eng. Senior Engineer / Manager of Contract Administration DSEL david schaeffer engineering ltd 120 Iber Road, Unit 203 Stittsville, ON K2S 1E9 phone: (613) ext 222 fax: (613) cell: (613) mwingate@dsel.ca This , including any attachments, is for the sole use of the intended recipient(s) and may contain private, confidential, and privileged information. Any unauthorized review, use, disclosure, or distribution is prohibited. If you are not the intended recipient or if this information has been inappropriately forwarded to you, please contact the sender by reply and destroy all copies of the original. This originates from the City of Ottawa system. Any distribution, use or copying of this or the information it contains by other than the intended recipient(s) is unauthorized. If you are not the intended recipient, please notify me at the telephone number shown above or by return and delete this communication and any copy immediately. Thank you. 4

29 Robert Freel From: Sent: To: Subject: Robert Freel May :45 PM White, Joshua 460 St. Laurent Boulevard Hi Josh, I just wanted to summarize for our report, the required stormwater management criteria we discussed for 460 St. Laurent is as follows: An Allowable release rate of 24.9L/s calculated based on the Rational Method Runoff Coefficient of 0.5 and employing the City of Ottawa IDF parameters for a 5-year storm with a time of concentration equal to 20 minutes. All storms up to and including the City of Ottawa 100-year design event are to be attenuated on site. Quality controls to be coordinated with the RVCA If you could confirm this is correct or provide any corrections in a reply that would be appreciated. Also the estimated wastewater generation from the site for coordination is 4.97L/s. Let me know if you have any questions. Regards, Bobby Freel, EIT. DSEL david schaeffer engineering ltd. 120 Iber Road, Unit 203 Stittsville, ON K2S 1E9 Phone: (613) Ext. 258 Fax: (613) rfreel@dsel.ca This , including any attachments, is for the sole use of the intended recipient(s) and may contain private, confidential, and privileged information. Any unauthorized review, use, disclosure, or distribution is prohibited. If you are not the intended recipient, or if this information has been inappropriately forwarded to you, please contact the sender by reply and destroy all copies of the original. 1

30 Robert Freel From: Sent: To: Subject: Robert Freel May :12 PM White, Joshua 460 St. Laurent Blvd Hi Josh, We are looking for any stormwater quantity criteria required for this site. I have contacted the RVCA with regards to quality control as it appears the storm sewer outlets approximately 500m north to an unnamed watercourse. Do you have any information with respect to the capacity of the storm and sanitary sewers, is there a preferred connection point for the development i.e. The existing sewers on Dunbarton or the proposed relocated sewers? Further please see below the estimated water demand of the proposed site for coordinating the watermain boundary conditions. o Location of service 460 St. Laurent Blvd (see attached map), ideal connection point would be to the exist 200mm service running through the site from Dunbarton CRT. This service appears to be capped off, are you able to determine if it is servicing any other buildings or is there potential to remove the dead end rather than relocating? o Type of development and the amount of fire flow required the development is a 14-storey residential building with ground floor commercial space and underground parking. The maximum required fire flow is 9,000 L/min o L/min L/s Avg. Daily Max Day Peak Hour

31 Robert Freel From: Sent: To: Subject: Jocelyn Chandler May :10 AM Robert Freel RE: 460 St. Laurent Blvd Hi Bobby, As per our discussion this morning: I do not have water quality or fish data on eth receiving unnamed watercourse. The distance to the outlet is short as you noted, but it does have a section between the Ottawa River and the upstream portion which is entombed. The sketch of the site plan shows considerable parking area, split with roof top. The RVCA will not be recommending specific quality controls for the site based on eth above information, but any swm design (such as a grassed swale) that will reduce sediment would certainly be considered appropriate and commendable from a environmental consideration perspective. Thank you for contacting me, Jocelyn Jocelyn Chandler M.Pl. MCIP, RPP. Planner, RVCA x1137 jocelyn.chandler@rvca.ca mail: Box Rideau Valley Dr., Manotick, ON K4M 1A5 courier: 3889 Rideau Valley Dr., Nepean, ON K2C 3H1 This message may contain information that is privileged or confidential and is intended to be for the use of the individual(s) or entity named above. This material may contain confidential or personal information which may be subject to the provisions of the Municipal Freedom of Information & Protection of Privacy Act. If you are not the intended recipient of this , any use, review, revision, retransmission, distribution, dissemination, copying, printing or otherwise use of, or taking of any action in reliance upon this , is strictly prohibited. If you have received this in error, please contact the sender and delete the original and any copy of the and any printout thereof, immediately. Your cooperation is appreciated. From: Robert Freel [mailto:rfreel@dsel.ca] Sent: May 16, :13 PM To: Jocelyn Chandler Subject: RE: 460 St. Laurent Blvd Hi Jocelyn, Please find attached a copy of the site plan. I m not sure how clear it is but the grey box in the front is the building, with the outdoor parking running along the west side of the building, under the overhead hydro lines. Let me know if you have any other questions. Also wanted to ask I had been using the CA geocortex mapping site to look at flood plain in the RVCA/MVC/SNC area but it seems to have been taken down; do you know of any other resources I could look to when doing preliminary investigation? Regards, 1

32 Thnaks, 3

33 APPENDIX B Water Supply

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35 Brigil 460 St. Laurent Existing Conditions Water Demand Design Flows per Unit Count City of Ottawa - Water Distribution Guidelines, July 2010 Domestic Demand Type of Housing Per / Unit Units Pop Single Family Semi-detached Townhouse Apartment 0 Bachelor Bedroom Bedroom Bedroom Average Pop Avg. Daily Max Day Peak Hour m 3 /d L/min m 3 /d L/min m 3 /d L/min Total Domestic Demand Institutional / Commercial / Industrial Demand Avg. Daily Max Day Peak Hour Property Type Unit Rate Units m 3 /d L/min m 3 /d L/min m 3 /d L/min Commercial floor space 2.5 L/m 2 /d Office 75 L/9.3m 2 /d Restaurant* 125 L/seat/d Industrial - Light 35,000 L/gross ha/d Industrial - Heavy 55,000 L/gross ha/d * Estimated number of seats at 1seat per 9.3m 2 Total I/CI Demand Total Demand Z:\Projects\11-538_Brigil_640-St.Laurent\B_Design\B1_Analysis\wtr _438_rdf

36 Brigil 460 St. Laurent Proposed Conditions Water Demand Design Flows per Unit Count City of Ottawa - Water Distribution Guidelines, July 2010 Domestic Demand Type of Housing Per / Unit Units Pop Single Family Semi-detached Townhouse Apartment 0 Bachelor Bedroom Bedroom Bedroom Average Pop Avg. Daily Max Day Peak Hour m 3 /d L/min m 3 /d L/min m 3 /d L/min Total Domestic Demand Institutional / Commercial / Industrial Demand Avg. Daily Max Day Peak Hour Property Type Unit Rate Units m 3 /d L/min m 3 /d L/min m 3 /d L/min Commercial floor space 2.5 L/m 2 /d Office 75 L/9.3m 2 /d Industrial - Light 35,000 L/gross ha/d Industrial - Heavy 55,000 L/gross ha/d Total I/CI Demand Total Demand Z:\Projects\11-538_Brigil_640-St.Laurent\B_Design\B1_Analysis\wtr _438_rdf

37 # # FAX TRANSMISSION FORM - Supply Pressure/Flow Capacity Date/Time: 11/11/01-14:35:46 City of Ottawa Our File: Transportation Utilities and Public Works 1 of 2 Page(s) Customer Service & Operational Support 951 Clyde Avenue Ottawa, On, K1Z 5A6 Joseph Hannewyk joseph.hannewyk@ottawa.ca Water Resources Analyst phone x22617 fax To: Robert Freel Company: DSEL_David Schaeffer Engineering Ltd. Tel: (613) ext.258 Fax: (613) Pressure Only? (Y): Location: St Brittany Request_dt: 11/11/01-14:29:27 Request Line Ref# rfreel@dsel.ca Preferred Response Method: Inspection Flow Residual Pressure (psi) Flow (igpm) Date Hydrant Hydrant Static Dynamic Pitot 20 psi 2011/10/ > /10/ > Note: the computed flows are approximate and performed for hydrant colour coding purposes, thus these values are not intended for design purposes. Ref# 6117

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39 APPENDIX C Wastewater Collection

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41 Brigil 460 St. Laurent Existing Conditions Existing Wastewater Design Flows per Unit Count City of Ottawa Sewer Design Guidelines, 2004 Site Area Extraneous Flow Allowances Infiltration / Inflow ha 0.07 L/s Domestic Contributions Unit Type Unit Rate Units Pop Single Family Semi-detached and duplex Duplex Townhouse Apartment Bachelor Bedroom Bedroom Bedroom Average Total Pop 0 Average Domestic Flow 0.00 L/s Peaking Factor 4 Peak Domestic Flow 0.00 L/s Institutional / Commercial / Industrial Contributions Property Type Unit Rate No. of Units Avg Wastewater (L/s) Commercial floor space* 5 L/m 2 /d 0.00 Hospitals 900 L/bed/d 0.00 School 70 L/student/d 0.00 Industrial - Light** 35,000 L/gross ha/d Industrial - Heavy** 55,000 L/gross ha/d 0.00 Average I/C/I Flow 0.10 Peak Institutional / Commercial Flow 0.00 Peak Industrial Flow** 0.41 Peak I/C/I Flow 0.41 * assuming a 12 hour commercial operation ** peak industrial flow per City of Ottawa Sewer Design Guidelines Appendix 4B Total Estimated Average Dry Weather Flow Rate Total Estimated Peak Dry Weather Flow Rate Total Estimated Peak Wet Weather Flow Rate 0.10 L/s 0.41 L/s 0.48 L/s Z:\Projects\11-538_Brigil_640-St.Laurent\B_Design\B1_Analysis\san _rdf DSEL

42 Brigil 460 St. Laurent Proposed Conditions Wastewater Design Flows per Unit Count City of Ottawa Sewer Design Guidelines, 2004 Site Area Extraneous Flow Allowances Infiltration / Inflow ha 0.07 L/s Domestic Contributions Unit Type Unit Rate Units Pop Single Family Semi-detached and duplex Townhouse Stacked Townhouse Apartment Bachelor Bedroom Bedroom Bedroom Average Total Pop 292 Average Domestic Flow 1.18 L/s Peaking Factor 4.00 Peak Domestic Flow 4.73 L/s Institutional / Commercial / Industrial Contributions Property Type Unit Rate No. of Units Avg Wastewater (L/s) Commercial floor space* 5 L/m 2 /d Hospitals 900 L/bed/d 0.00 School 70 L/student/d 0.00 Industrial - Light** 35,000 L/gross ha/d 0.00 Industrial - Heavy** 55,000 L/gross ha/d 0.00 Average I/C/I Flow 0.11 Peak Institutional / Commercial Flow 0.16 Peak Industrial Flow** 0.00 Peak I/C/I Flow 0.16 * assuming a 12 hour commercial operation ** peak industrial flow per City of Ottawa Sewer Design Guidelines Appendix 4B Total Estimated Average Dry Weather Flow Rate Total Estimated Peak Dry Weather Flow Rate Total Estimated Peak Wet Weather Flow Rate 1.29 L/s 4.90 L/s 4.97 L/s Z:\Projects\11-538_Brigil_640-St.Laurent\B_Design\B1_Analysis\san _rdf DSEL

43 APPENDIX D Stormwater Management

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45 Brigil 460 St. Laurent Existing Conditions Estimated Peak Stormwater Flow Rate City of Ottawa Sewer Design Guidelines, 2004 Existing Drainage Area Charateristics Area C t c Estimated Peak Flow ha 0.53 Rational Method runoff coefficient 10.0 min 2-year 5-year 100-year i mm/hr Q L/s Z:\Projects\11-538_Brigil_640-St.Laurent\B_Design\B1_Analysis\stm _538_rdf DSEL

46 Brigil 460 St. Laurent Proposed Conditions Stormwater - Proposed Development City of Ottawa Sewer Design Guidelines, 2004 Target Flow Rate Area C 0.26 ha 0.50 Rational Method runoff coefficient 2-year 5-year t c i Q actual Q release i Q actual Q release (min) (mm/hr) (L/s) (L/s) (mm/hr) (L/s) (L/s) Estimated Post Development Peak Flow from Unattenuated Areas Total Area C ha 0.85 Rational Method runoff coefficient 5-year 100-year t c i Q actual Q release Q stored V stored i Q actual Q release Q stored V stored (min) (mm/hr) (L/s) (L/s) (L/s) (m 3 ) (mm/hr) (L/s) (L/s) (L/s) (m 3 ) Estimated Post Development Peak Flow from Attenuated Areas Total Area C 0.23 ha 0.85 Rational Method runoff coefficient 5-year 100-year t c i Q actual Q release Q stored V stored i Q actual Q release Q stored V stored (min) (mm/hr) (L/s) (L/s) (L/s) (m 3 ) (mm/hr) (L/s) (L/s) (L/s) (m 3 ) year Q attenuated 6.12 L/s 100-year Q attenuated L/s 5-year Max. Storage Required 42.9 m year Max. Storage Required 85.9 m 3 Summary of Release Rates and Storage Volumes Control Area 5-Year 5-Year 100-Year 100-Year Release Storage Release Storage Rate Rate (L/s) (m 3 ) (L/s) (m 3 ) Unattenuated Areas Attenutated Areas Total Z:\Projects\11-538_Brigil_640-St.Laurent\B_Design\B1_Analysis\stm _538_rdf DSEL

47 DRAWINGS / FIGURES

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