STORM WATER REPORT. Proposed Row House Complex Clare and Hilson 566 Hilson Ave. & 148 Clare St. Ottawa, Ontario PREPARED FOR:

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1 Civil Geotechnical Structural Environmental 210 Prescott Street, Unit 1 (613) P.O. Box 189 Kemptville, Ontario K0G 1J0 FAX: (613) STORM WATER REPORT Proposed Row House Complex Clare and Hilson 566 Hilson Ave. & 148 Clare St. Ottawa, Ontario PREPARED FOR: Falsetto Homes Inc. 52 Sullivan Avenue Ottawa Ontario K2G 1V2 PROJECT # DISTRIBUTION: 6 copies City of Ottawa 2 copy Falsetto Homes Inc. 1 copy Kollaard Associates Inc. Revision 0 - Prepared for Site Plan Control June 20, 2014 Professional Engineers Authorized by the Association of Professional Engineers

2 Storm Water Report Row House Development Falsetto Homes Inc, Clare St. and Hilson Ave., Ottawa, Ontario June 20, 2014 ii File No Table of Contents Introduction... 3 Current (Pre-development) Site Conditions... 4 Proposed Development... 5 Storm Water Quantity... 5 Pre-Development Baseline Conditions... 6 Post-Development Stage... 7 Controlled and Uncontrolled Areas... 7 Impervious Ratio... 8 Storm water Release Rate From Uncontrolled Area... 8 Allowable Controlled Area Release Rate... 9 Storage and Release Rate... 9 Storm Water Quality Control Sediment and Erosion Control Related Drawings Drawing # GER Grading & Erosion Control Plan Drawing # SER Site Servicing Plan Drawing # PP Plan and Profile (Clare St.) Attachments Figure 1 Controlled and Uncontrolled areas Appendix A Appendix B Appendix C Appendix D Appendix E Stormwater Management - Rational Method Allowable Controlled Area Release Rate Stormwater Management - Rational Method Calculation Sheet Actual Discharge Rate And Storage Volume Requirements Stormwater Management - Rational Method Available Surface Storage Volume With Respect to Ponding Depth Hydrovex Flow Regulator Information Stormceptor STC 300 Design Information Civil Geotechnical Structural Environmental Hydrogeology

3 Storm Water Report Row House Development Falsetto Homes Inc, Clare St. and Hilson Ave., Ottawa, Ontario June 20, 2014 File No INTRODUCTION Kollaard Associates Inc. was retained by Falsetto Homes Inc. to provide a storm water management design system for the proposed 7 unit - three storey row house building complex and 2 unit duplex building at 566 Hilson Avenue and 148 Clare Street, Ottawa, Ontario. The proposed development site has an area of about 1266 square metres. The site is currently occupied by two existing family dwellings and a detached garage with combined building areas of 181 square metres and by driveways with combined asphaltic concrete surfaced areas of about 87 square metres. Existing stormwater runoff in general consists of uncontrolled sheet flow to Hilson Avenue and Clare Street. The proposed development will consist of about 494 square metres of building, about 450 square metres of landscaping and about 322 square metres of asphalt concrete surfaced access driveways and sidewalks. It is understood that the site is subject to the following stormwater management criteria: The post-development runoff rate from the controlled areas of the site should not exceed the allowable runoff rate from the site based on the five-year pre-development design storm for all storm events up to and including the 100-year storm event; The pre-development runoff co-efficient should be taken as the lesser of existing site conditions or 0.5; The existing runoff from adjacent properties onto the site must be accommodated by the proposed stormwater management design; and An enhance level of quality control must be provided. The stormwater management design consists of directing stormwater runoff originating on controlled areas of the site, including the roof of the proposed buildings, to a storm sewer which is designed to back up to a stormwater attenuation pond located in the south end of the property. Outflow from the pond will be directed to the municipal storm sewer along Clare Street. The outlet flow rate to the municipal storm sewer will be controlled such that, flow rates in excess of predevelopment rates will be temporarily stored in the attenuation pond. Civil Geotechnical Structural Environmental Hydrogeology

4 Storm Water Report Row House Development Falsetto Homes Inc, Clare St. and Hilson Ave., Ottawa, Ontario June 20, 2014 File No CURRENT (PRE-DEVELOPMENT) SITE CONDITIONS The site is located south of Clare Street and west of Hilson Avenue in Ottawa, Ontario. The site has a total area of about 1266 square meters which is fully developed. The site is currently occupied by two existing single family dwellings, a garage, and about 181 square metres of asphaltic concrete surfaced driveway. An additional 74 square metres of landscaped area will drain onto the site from the adjacent property southeast of the site after development is complete. This offsite runoff area was accounted for the post-development analysis but was not used in the pre-development calculations to determine allowable runoff. The predevelopment runoff co-efficient for the site was calculated as follows: Table I Pre-Development Area and C Factors Coefficient of Runoff Description 5-year 100-year Area m 2 Area (ha) Total Site Area Building Area Landscape Area Asphalt Concrete Surface Driveway Weighted Avg. C Based on the existing ground cover, the pre-development runoff coefficient was calculated as C = 0.43 for the 5-year design storm and C = 0.51 for the 100-year design storm. The predevelopment runoff coefficient used for the purpose of this stormwater management design based on the Ottawa stormwater design guidelines was C = 0.43 for the 5-year design storm event and C = 0.5 for the 100-year design storm event. Existing storm water runoff from 80% of the site in general consists of uncontrolled sheet flow towards the streets along the east and north edges of the site where it is directed to catch basins along Hilson Avenue and Clare Street. The runoff from the remaining about 20% of the site is consists of uncontrolled runoff to the south of the site. Civil Geotechnical Structural Environmental Hydrogeology

5 Storm Water Report Row House Development Falsetto Homes Inc, Clare St. and Hilson Ave., Ottawa, Ontario June 20, 2014 File No PROPOSED DEVELOPMENT The proposed development of the site consists of about 494 square metres of building area, 450 square metres of landscaping and 322 square metres of concrete surfaced driveway and sidewalks. The proposed building and concrete surface driveway and sidewalk areas will have a combined area of some 816 square metres of impervious surface. Most surface runoff and roof drainage from the development will be directed to an underground storm sewer located between the proposed townhome and duplex building. The sewer is designed to back up to a dry pond located at the south end of the site with some runoff directly entering the proposed dry pond. Outflow from the dry pond will be directed through the proposed storm sewer to a proposed extension of the existing municipal storm sewer along Clare Street. The outlet flow rate to the municipal storm sewer will be controlled such that, flow rates in excess of predevelopment rates will be temporarily stored in the dry pond. Runoff from the uncontrolled areas comprised of the remainder of the site will be directed in sheet flow to the adjacent streets east and north of the site. STORM WATER QUANTITY Peak Flow for runoff quantities for the Pre-Development and Post-Development stages of the project were calculated using the rational method. The rational method is a common and straightforward calculation, which assumes that the entire drainage area is subject to uniformly distributed rainfall. The formula is: Q CiA 360 Where Q is the Peak runoff measured in m 3 /s C is the Runoff Coefficient, Dimensionless A is the runoff area in hectares i is the storm intensity measure in mm/hr Civil Geotechnical Structural Environmental Hydrogeology

6 Storm Water Report Row House Development Falsetto Homes Inc, Clare St. and Hilson Ave., Ottawa, Ontario June 20, 2014 File No All values for intensity, i, for this project were derived from IDF curves provided by the City of Ottawa for data collected at the Ottawa International airport. For this project two return periods, were considered, 5-year and 100-year design storm events. The formulas for each are: 5-Year Event i t c 100-Year Event i t c where t c is time of concentration Pre-Development Baseline Conditions The pre-development baseline runoff rate was established using the rational method. Following the method described in the City of Ottawa Sewer Design Guidelines - Inlet Time Graph (Appendix 5- D.1), the time of concentration was estimated to be 15 minutes. The distance of travel for the area contained within the limit of development is approximately 30 metres over a surface with an average slope of about 1.0 percent and a runoff coefficient of about C =0.43. From the Ottawa Sewer Design Guidelines a 15-minute duration yields an intensity of mm/hr for a 5-year design storm event on the IDF curve, and an intensity of mm/hr for a 100-year design storm event. As discussed above, the pre-development runoff coefficient were calculated as C = 0.43 for the 5-year design storm and C = 0.51 for the 100-year design storm, for design purposes the minimum runoff coefficient of C = 0.50 will be used for the 100-year design storm. The existing runoff for the site based on the pre-development conditions and the storm water management criteria: Q CiA 360 Civil Geotechnical Structural Environmental Hydrogeology

7 Storm Water Report Row House Development Falsetto Homes Inc, Clare St. and Hilson Ave., Ottawa, Ontario June 20, 2014 File No For the 5-year Storm event = (0.43 x x 0.127)/360 = m 3 /s = 12.7 Litres per second For the 100-year Storm event = (0.50 x x 0.127)/360 = m 3 /s = 25.2 Litres per second Post-Development Stage The proposed development consists of a 7 unit - three storey row house building complex, a 2 unit duplex building, asphaltic concrete and landscaping. The post-development site has been divided into controlled and uncontrolled areas. The uncontrolled area includes the areas where the runoff rate is not being controlled by the stormwater management design. The controlled areas include all the areas from which the runoff is being retained and controlled in the post development storm water management design. Controlled and Uncontrolled Areas For the purposes of this storm water management design, the site has been divided into uncontrolled and controlled areas. The uncontrolled area consists of the landscape area and walkways in the front yards of each unit, and the landscaped area beside the duplex on the western edge of the site. The controlled area consists of the remaining portion of the catchment area, including the proposed buildings, asphalt parking area, storm water pond and remaining landscaped areas, from which runoff is directed to the underground storm sewer in the center of the site. As previously indicated, there is an additional 74 square metres of offsite landscaped area directing runoff towards the site from the adjacent property to southeast of the site. This runoff will be directed to the proposed storm water pond and will be controlled and treated with the runoff generated on site. Controlled and uncontrolled areas including the offsite area are listed in Table II below and shown on the attached Figure 1. Civil Geotechnical Structural Environmental Hydrogeology

8 Storm Water Report Row House Development Falsetto Homes Inc, Clare St. and Hilson Ave., Ottawa, Ontario June 20, 2014 File No Table II - Post Development Area and C Factors Coefficient of Runoff Description 5-year 100-year Area m 2 Area (ha) TOTAL DEVELOPED AREA Total Building Area Controlled Building Areas Uncontrolled Building Areas Total Landscape Area (Grass, Shrub, Tree) Controlled Landscape Area Uncontrolled Landscape Area Total Asphaltic Concrete Surfaced Areas Controlled Asphalt Uncontrolled Asphalt Controlled Area Weighted Avg. C Uncontrolled Area Weighted Avg. C It is noted that the area in the above table includes the offsite area contributing runoff to the stormwater management works. Impervious Ratio The impervious ratio is equal to the total impervious area divided by the total area, and is about 64.3 percent for the site. If the offsite area contributing to the stormwater management works is also considered, the impervious ratio would be equal to 60.9 percent. Storm water Release Rate From Uncontrolled Area The average runoff coefficient is C = 0.52 for the hectares of uncontrolled area for the 5-year design storm. A post-development time of concentration of 10 minutes corresponds to a storm intensity of mm/hr on the 5-year IDF curve respectively. The runoff rate from the uncontrolled areas of the site during a 5-year storm event was therefore calculated using the Rational Method as: Q CiA 360 Q uncontrolled =0.0031m 3 /s (3.1 L/s) for a 5-year storm event; and Civil Geotechnical Structural Environmental Hydrogeology

9 Storm Water Report Row House Development Falsetto Homes Inc, Clare St. and Hilson Ave., Ottawa, Ontario June 20, 2014 File No Allowable Controlled Area Release Rate The allowable controlled area release rate is equal to the total allowable release rate from the site based on the pre-development baseline conditions for the 5-year design storm event. The releasable flow rate from the controlled area is: Q controlled = Q total allowable - Q uncontrolled For the 5-year Storm event Q controlled = = 9.6 L/s For the 100-year Storm event Q controlled = 9.6 L/s The allowable controlled area release rate for the site is summarized in Appendix A. STORAGE AND RELEASE RATE In order to achieve the allowable controlled area storm water release rate, storm water runoff from the controlled areas will be directed to the proposed storm sewer catch basins located between the proposed buildings as well as the proposed stormwater attenuation pond to the south of the site. In general, the storage volume of the storm sewer catchment consists of the dry pond to which water will be backed up to, which is caused by restricting the release rate into the municipal storm sewer extension. The stormwater attenuation pond is outlet at an elevation of metres. Overflow from the storage area to the adjacent ground surface occurs at an elevation of metres. The stormwater attenuation pond has a total volume above the outlet of 29.2 cubic metres. The proposed storm sewer has a storage volume of about 4.9 cubic metres. Two manholes and one catch basin have a storage volume of about 1.0 cubic metres each. As such there is 35.1 cubic metres of storage available for the runoff from the catchments out letting to the municipal storm Civil Geotechnical Structural Environmental Hydrogeology

10 Storm Water Report Row House Development Falsetto Homes Inc, Clare St. and Hilson Ave., Ottawa, Ontario June 20, 2014 File No sewer on Clare Street. A summary of the available storage volume with respect to elevation is provided in the attached Appendix C. From the table in the attached Appendix B, a maximum storage requirement during the 100-year design storm event is 21.5 cubic metres. This corresponds to a maximum ponding depth of 0.2 metres in the stormwater attenuation pond. Control of Release Rate The proposed surface storage will release water to a proposed storm sewer extension to the existing municipal storm drain running along Clare Street to the north of the site. The flow rate into the storm drain will be restricted by an inlet control device (ICD) that limits the flow into the municipal system and backs up any excess into the proposed dry pond in the system. A Hydrovex 100-VHV-1 vertical vortex flow regulator or approved alternative will be used. The ICD will continue to release water after the storm event has passed until levels are lowered to pre event conditions. The maximum allowable controlled area post development release rate is 9.8 litres per second. The Hydrovex ICD can be purchased from John Meunier Inc. and should be ordered for the following parameters; Model number 100-VHV-1 Outlet pipe specification: 375mm diameter PVC SDR 28 Discharge: 9.6 L/s Upstream Head: 2.34 m Manhole Diameter: 1200 mm diameter Minimum Clearance "H" = 8 inches The ICD was selected in order to ensure that the allowable maximum release rate for both 5-year and 100-year design storm events are not exceeded. STORM WATER QUALITY CONTROL The Ministry of Environment, Storm Water Management Planning and Design Manual (Manual) details the requirements for storm water quality based on the receiving body of water. The receiving body of water for this site is the Ottawa River which is a sensitive fish habitat. As such an enhanced level of protection is required. Enhanced protection corresponds to the end-of-pipe storage volumes required for the long-term average removal of 80% of suspended solids. Civil Geotechnical Structural Environmental Hydrogeology

11 Storm Water Report Row House Development Falsetto Homes Inc, Clare St. and Hilson Ave., Ottawa, Ontario June 20, 2014 File No This will be achieved with the use of a Stormceptor STC 300. The Stormceptor is a patented storm water treatment unit designed by Imbrium Systems Inc to provide storm water treatment. The Stormceptor STC is designed to maintain continuous positive treatment of total suspended solids (TSS), regardless of flow rate, and is also designed to remove a wide range of particle sizes as well as free oils, heavy metals and nutrients that attach to fine sediment. The Stormceptor STC 300 will be placed in a manhole downstream of the Hydrovex Vertical Vortex Flow Regulator which will control the rate of flow through the Stormceptor. The location of the Stormceptor is shown on Kollaard Associates Inc. Drawing # SER - Site Servicing Plan. The Stormceptor design and sizing information is attached in Appendix E. It should be noted that the Stormceptor Model Number STC 300 has an annual total suspended solids removal rate of 87 percent which is in excess of the MOE enhanced protection requirement rate of 80 percent total suspended solids removal. SEDIMENT AND EROSION CONTROL The owner (and/or contractor) agrees to prepare and implement an erosion and sediment control plan at least equal to the stated minimum requirements and to the satisfaction of the City of Ottawa, appropriate to the site conditions, prior to undertaking any site alterations (filling, grading, removal of vegetation, etc.) and during all phases of site preparation and construction in accordance with the current best management practices for erosion and sediment control. It is considered to be the owners and/or contractors responsibility to ensure that the erosion control measures are implemented and maintained. The site in general is relatively flat at an average slope of 1.0%. In order to limit the amount of sediment carried in storm water runoff from the site during construction, it is recommended to install a silt fence along the property line on all sides of the site, as described in Kollaard Associates Drawing # GEP - Grade & Erosion Control Plan. The silt fence may be polypropylene, nylon, and polyester or ethylene yarn. If a standard filter fabric is used, it must be backed by a wire fence supported on posts not over Civil Geotechnical Structural Environmental Hydrogeology

12 Storm Water Report Row House Development Falsetto Homes Inc, Clare St. and Hilson Ave., Ottawa, Ontario June 20, 2014 File No m apart. Extra strength filter fabric may be used without a wire fence backing if posts are not over 1.0 m apart. Fabric joints should be lapped at least 150 mm (6") and stapled. The bottom edge of the filter fabric should be anchored in a 300 mm (1 ft) deep trench, to prevent flow under the fence. Sections of fence should be cleaned, if blocked with sediment and replaced if torn. Filter cloths should be installed across existing storm manhole and catch basin lids. As well, filter cloths should be installed across the proposed catch basin lids immediately after the catch basins are placed. The filter cloths should only be removed once the asphaltic concrete is installed and the site is cleaned. The exposed landscaped areas of the site should be mulched and seeded with a rapid growing grass mixture or sodded as soon as possible. The proposed granular and asphaltic concrete surfaced areas should be surfaced as soon as possible. The silt fences should only be removed once the site is stabilized and vegetation is established. These measures will reduce the amount of sediment carried from the site during storm events that may occur during construction. We trust that this report provides sufficient information for your present purposes. If you have any questions concerning this report or if we can be of any further assistance to you on this project, please do not hesitate to contact our office. Sincerely, Kollaard Associates, Inc. June Steven dewit, P.Eng. Civil Geotechnical Structural Environmental Hydrogeology

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14 Storm Water Report Row House Development Falsetto Homes Inc, Clare St. and Hilson Ave., Ottawa, Ontario June 20, 2014 File No APPENDIX A STORMWATER MANAGEMENT - RATIONAL METHOD ALLOWABLE CONTROLLED AREA RELEASE RATE Civil Geotechnical Structural Environmental Hydrogeology

15 APPENDIX A: STORMWATER MANAGEMENT MODEL ALLOWABLE CONTROLLED AREA RELEASE RATE Client: Falsetto Homes Inc. Job No.: Location: 566 Hilson Ave & 148 Clare St. Ottawa, Ontario Date: June 20, 2014 Design Criteria: Pre-Development Site Area Total hectares Controlled hectares Uncontrolled hectares Time of Concentration, (Pre) Tc 5 year= 15 minutes Time of Concentration, (Pre) Tc 100 year= 15 minutes Pre-Development C-5year = 0.43 Pre-Development C-100year= 0.50 Post-Development Site Area Total hectares Controlled hectares Uncontrolled hectares Post-Development C (Controlled) 5-year= 0.65 Post-Development C (Uncontrolled) 5-year= 0.52 Post-Development C (Controlled) 100-year= 0.73 Post-Development C (Uncontrolled) 100-year= 0.59 Time of Concentration, (Post) Tc 5 year= 10 minutes Time of Concentration, (Post) Tc 100 year = 10 minutes 5 YEAR STORM I = mm/hr CALCULATED PRE-DEVELOPMENT RUNOFF RATE = m 3 /s (note 1) 100 YEAR STORM I = mm/hr CALCULATED PREDEVELOPMENT RUNOFF RATE = m 3 /s (note 1) 5 YEAR STORM RUNOFF EVENT ALLOWABLE CONTROLLED AREA RELEASE RATE CALCULATION PRE-DEVELOPMENT POST-DEVELOPMENT ALLOWABLE RAINFALL RAINFALL PEAK CONTROLLED UNCONTROLLED TOTAL RELEASE RATE DURATION INTENSITY RUNOFF PEAK RUNOFF PEAK RUNOFF PEAK FLOW (min.) (mm/hr) (m 3 /s) (m 3 /s) (m 3 /s) (m 3 /s) m 3 /s Allowable release rate from the controlled area of the site for a 5 year storm event based on a post-development Time of concentration of 10 minutes is m 3 /s (note 2) 100 YEAR STORM RUNOFF EVENT ALLOWABLE CONTROLLED AREA RELEASE RATE CALCULATION PRE-DEVELOPMENT POST-DEVELOPMENT ALLOWABLE RAINFALL RAINFALL PEAK CONTROLLED UNCONTROLLED TOTAL RELEASE RATE DURATION INTENSITY RUNOFF PEAK RUNOFF PEAK RUNOFF PEAK FLOW (min.) (mm/hr) (m 3 /s) (m 3 /s) (m 3 /s) (m 3 /s) m 3 /s column 1 column 2 column 3 column 4 column 5 column 6 column 7 Allowable release rate from the controlled area of the site for a 100 year storm event based on a post-development Time of concentration of 10 minutes is m 3 /s (note 2) Note 1 Is equal to the pre-development runoff rate at the designated time of concentration for the catchment Note 2 Allowable release rate is obtained from column 7 for the indicated time of concentration for post development conditions. Allowable release rate for the 100 year storm is restricted to the allowable release rate for the 5-year storm event. Column 1 Rainfall Duration in minutes Column 2 Rainfall Intensity calculated using the City of Ottawa IDF curve for the Ottawa Airport, Equations are contained in Storm Report Column 3 Predevelopment Peak Runoff Calculated Using the Rational Method Q = CIA where C = Predevelopment Runoff Coefficient indicated near the top of the page. C is different for the 5 and 100 year events. Column 4 Post development Peak Runoff. Q = CIA where C = the coefficient for the uncontrolled Area and I is located in Column 2 Column 5 Post development Peak Runoff. Q = CIA where C = the coefficient for the controlled Area and I is located in Column 2 Column 6 Column 4 + Column 5 Column 7 Is equal to the pre-development runoff rate less the uncontrolled peak runoff

16 Storm Water Report Row House Development Falsetto Homes Inc, Clare St. and Hilson Ave., Ottawa, Ontario June 20, 2014 File No APPENDIX B STORMWATER MANAGEMENT - RATIONAL METHOD CALCULATION SHEET ACTUAL DISCHARGE RATE AND STORAGE VOLUME REQUIREMENTS Civil Geotechnical Structural Environmental Hydrogeology

17 APPENDIX B: STORMWATER MANAGEMENT MODEL RATIONAL METHOD CALCULATION SHEET - ACTUAL DISCHARGE RATE AND STORAGE VOLUME REQUIREMENTS Client: Falsetto Homes Inc. Job No.: Location: 566 Hilson Ave & 148 Clare St. Date: June 20, 2014 Design Criteria: Pre-development Total Site Area = hectares Pre-development C 5 Year = 0.43 Total Controlled Area from Site = Total Uncontrolled Area from Site = Impervious ratio = hectares hectares Post-development Total Site Area = Total Controlled Area from Site = Total Uncontrolled Area from Site = Impervious ratio = hectares Post-Development C (Controlled) 5 Year = hectares Post-Development C (Uncontrolled) 5 Year = hectares Post-Development C (Controlled) 100 Year = Post-Development C (Uncontrolled) 100 Year = 0.59 Maximum Allowable Release Rate from storage 5 year Storm Event (m 3 /s) Maximum Allowable Release Rate from storage 100 year Storm Event (m 3 /s) 5 YEAR STORM RUNOFF EVENT CALCULATION OF MAXIMUM STORAGE AND ACTUAL FLOW RATE FROM SITE PRE-DEVELOPMENT POST-DEVELOPMENT RAINFALL RAINFALL PEAK TOTAL UNCONTROLLED CONTROLLED ACTUAL REQ'D TOTAL DURATION INTENSITY RUNOFF RUNOFF SITE RUNOFF SITE STORAGE STORAGE FLOW RATE RUNOFF RELEASE RATE FROM SITE (min.) (mm/hr) (m 3 /s) (m 3 ) (m 3 /s) (m 3 /s) m 3 /s (m 3 ) (m 3 /s) Max Storage Volume YEAR STORM RUNOFF EVENT CALCULATION OF MAXIMUM STORAGE AND ACTUAL FLOW RATE FROM SITE PRE-DEVELOPMENT POST-DEVELOPMENT RAINFALL RAINFALL PEAK TOTAL UNCONTROLLED CONTROLLED ACTUAL REQ'D TOTAL DURATION INTENSITY RUNOFF RUNOFF SITE RUNOFF SITE STORAGE STORAGE FLOW RATE RUNOFF RELEASE RATE FROM SITE (min.) (mm/hr) (m 3 /s) (m 3 ) (m 3 /s) (m 3 /s) m 3 /s (m 3 ) (m 3 /s) column 1 column 2 column 3 column 4 column 5 column 6 column 7 column 8 column 9 Max Storage Volume 21.5 Column 1 Rainfall Duration in minutes Column 2 Rainfall Intensity calculated using the City of Ottawa IDF curve for the Ottawa Airport, Equations are contained in Storm Report Column 3 Predevelopment Peak Runoff Calculated Using the Rational Method Q = CIA where C = Predevelopment Runoff Coefficient indicated near the top of the page. C is different for the 5 and 100 year events. Column 4 Equal to the Rainfall intensity multiplied by the rainfall duration (Column 1 x Column 2 x 60 min/hr) Column 5 Post development Peak Runoff. Q = CIA where C = the coefficient for the uncontrolled Area and I is located in Column 2 Column 6 Post development Peak Runoff. Q = CIA where C = the coefficient for the controlled Area and I is located in Column 2 Column 7 Actual Storage Release Rate is a function of the release rate from the parking area storage at a given storage volume. Is calculated by Iteration using the storage discharge curve determined in Appendix D in conjunction with the storage requirement in Column 8 Column 8 Resulting storage requirement based on the actual discharge rate in column 7 calculated by iteration. Column 9 Sum of column 5 and column 7

18 Storm Water Report Row House Development Falsetto Homes Inc, Clare St. and Hilson Ave., Ottawa, Ontario June 20, 2014 File No APPENDIX C STORMWATER MANAGEMENT - RATIONAL METHOD AVAILABLE SURFACE STORAGE VOLUME WITH RESPECT TO PONDING DEPTH Civil Geotechnical Structural Environmental Hydrogeology

19 APPENDIX C: STORMWATER MANAGEMENT MODEL AVAILABLE SURFACE STORAGE VOLUME WITH RESPECT TO PONDING DEPTH Kollaard Associates Inc. Client: Falsetto Homes Inc. Job No.: Location: 566 Hilson Ave & 148 Clare St. Ottawa, Ontario Date: May 27, 2014 Layer Top Bottom Layer Cumulative Head on Release Rate Pond Thickness Layer Layer Volume Volume Hydrovex Hydrovex ICD Depth Elevation Area Area ICD m m m 2 m 2 m 3 m 3 m L/sec m Column 1 Column 2 Column 3 Column 4 Column 5 Column 6 Column 7 Column 8 Column 9 Column 1 Column 2 Column 3 Column 4 Column 5 Column 6 Column 7 Column 8 Column 9 Elevation Thickness of the layer with the top elevation indicated in column 1 on the same row and the bottom Surface area of the layer with the top elevation indicated in column 1 of the same row Surface area of the layer with the bottom elevation indicated in column 1 of the previous row Volume between the two areas defined as top layer area (column 3) and bottom layer area (column Is the sum of the volume in the current row with the volumes of the preceeding rows Is the difference in elevation between the center of the ICD and the Pond Surface Is the release rate of the ICD based on the head on the ICD. Is the maximum depth of the pond when the water surface is at the elevation in colume 1 of the current row

20 Storm Water Report Row House Development Falsetto Homes Inc, Clare St. and Hilson Ave., Ottawa, Ontario June 20, 2014 File No APPENDIX D HYDROVEX FLOW REGULATOR INFORMATION Civil Geotechnical Structural Environmental Hydrogeology

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30 Storm Water Report Row House Development Falsetto Homes Inc, Clare St. and Hilson Ave., Ottawa, Ontario June 20, 2014 File No APPENDIX E STORMCEPTOR STC 300 DESIGN INFORMATION Civil Geotechnical Structural Environmental Hydrogeology

31 Stormceptor Design Summary PCSWMM for Stormceptor Project Information Date 23/06/2014 Project Name Row House Development Project Number Location Designer Information Company Contact Notes N/A Hilson & Clare Kollaard Associates N/A Rainfall Name State OTTAWA MACDONALD-CARTIER INT'L A ON ID 6000 Years of Records 1967 to 2003 Latitude Longitude 45 19'N 75 40'W Water Quality Objective TSS Removal (%) 80 Drainage Area Total Area (ha) Imperviousness (%) 60.9 The Stormceptor System model STC 300 achieves the water quality objective removing 87% TSS for a City of Toronto (clay, silt and sand) particle size distribution. Upstream Storage Storage Discharge (ha-m) (L/s) 0 0 Stormceptor Sizing Summary Stormceptor Model TSS Removal % STC STC STC STC STC STC STC STC STC STC STC STC Stormceptor Design Summary - 1/2

32 Particle Size Distribution Removing silt particles from runoff ensures that the majority of the pollutants, such as hydrocarbons and heavy metals that adhere to fine particles, are not discharged into our natural water courses. The table below lists the particle size distribution used to define the annual TSS removal. City of Toronto (clay, silt and sand) Particle Size Distribution Specific Settling Specific Settling Particle Size Distribution Gravity Velocity Gravity Velocity µm % m/s µm % m/s Stormceptor Design Notes Stormceptor performance estimates are based on simulations using PCSWMM for Stormceptor version 1.0 Design estimates listed are only representative of specific project requirements based on total suspended solids (TSS) removal. Only the STC 300 is adaptable to function with a catch basin inlet and/or inline pipes. Only the Stormceptor models STC 750 to STC 6000 may accommodate multiple inlet pipes. Inlet and outlet invert elevation differences are as follows: Inlet and Outlet Pipe Invert Elevations Differences Inlet Pipe Configuration STC 300 STC 750 to STC STC 9000 to 6000 STC Single inlet pipe 75 mm 25 mm 75 mm Multiple inlet pipes 75 mm 75 mm Only one inlet pipe. Design estimates are based on stable site conditions only, after construction is completed. Design estimates assume that the storm drain is not submerged during zero flows. For submerged applications, please contact your local Stormceptor representative. Design estimates may be modified for specific spills controls. Please contact your local Stormceptor representative for further assistance. For pricing inquiries or assistance, please contact Imbrium Systems Inc., Stormceptor Design Summary - 2/2