FUNCTIONAL SERVICING AND STORM WATER MANAGEMENT STUDY PROPOSED COMMERCIAL BUILDING 128 REIS ROAD, CARP CITY OF 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) FUNCTIONAL SERVICING AND STORM WATER MANAGEMENT STUDY PROPOSED COMMERCIAL BUILDING 128 REIS ROAD, CARP CITY OF OTTAWA, ONTARIO PREPARED FOR: Winch Holding Ltd Landel Drive Ottawa, ON PROJECT # DISTRIBUTION: 4 copies City of Ottawa 1 copy Winch Holding Ltd. 1 copy Kollaard Associates Inc. Revision 0 - Issued for Site Plan Control June 21, 2013 Revision 1 As per City and MVCA Comments December 10, 2013 Professional Engineers Ontario Authorized by the Association of Professional Engineers of Ontario to offer professional engineering services.

2 Site Servicing and Storm Water Report Proposed Commercial Building Winch Holding Ltd. 128 Reis, Ottawa, Ontario Dec 10, File No Table of Contents 1. Introduction Existing Site Conditions Required Permits and Approvals Pre-submission consultation City of Ottawa Mississippi Valley Conservation References Water Supply Servicing Water Servicing Design Water supply Conclusions Wastewater Servicing Wastewater Design Wastewater Servicing Conclusions Stormwater Management Pre-development conditions Post-development Stormwater Management Design Criteria Proposed StormWater Management System Storm Water Quality Control Stormwater Servicing Conclusions Sediment and Erosion Control Utilities Conclusion...13 Figure 1 Figure 2 Key Plan Controlled and Uncontrolled Areas. Appendix A Stormwater Management - Rational Method Allowable Controlled Area Release Rate Appendix B Treatment Pond Volume and Discharge Rates Appendix C Stormwater Management Rational Method Calculation Sheet Actual Discharge Rate and Storage Volume Requirements Appendix D Design Calculations for Grassed Swale, Following MOE Guidelines Civil Geotechnical Structural Environmental Hydrogeology

3 Site Servicing and Storm Water Report Proposed Commercial Building Winch Holding Ltd. 128 Reis, Ottawa, Ontario Dec 10, File No INTRODUCTION Winch Holdings Ltd. has retained the services of Kollaard Associates Inc. to prepare site servicing and stormwater management plans in support of a site plan control application for 128 Reis Road, Carp. As illustrated in Key Plan, Figure 1, the subject property is situated on the north side of Reis Rd, in an existing rural industrial park east of Carp Road, about 3.2 km north of Highway 417. The property measures approximately 1.93 ha and is currently zoned RG4. The proposed development involves the construction of a warehouse of approximately 398 m 2 in building area, which is to include approximately 150 m 2 of second-storey office space. The proposed layout of the building, parking lots and landscaped areas are indicated on the site plan prepared by Ardington Design Consulting (Ardington). This report and the associated civil engineering drawings have been prepared based on the site plan by Ardington. The purpose of this report is to provide sufficient information to support the site plan control application with respect to site servicing and storm water management design. 1.1 EXISTING SITE CONDITIONS The site consists of an undeveloped lot located between two warehouse buildings in a rural general industrial subdivision within the Carp Road Corridor. The neighbouring property to the east is also owned by Winch Holdings Ltd. The subdivision is outside of the area serviced by City of Ottawa municipal water and sewers. As such, lots are serviced by private wells and on-site sewage systems. Drainage is provided by a roadside ditch along Reis Road which flows east to a municipal drain that discharges to Huntley Creek to the south of the subdivision. Under pre-development conditions, the site under consideration was grass-covered and drainage was by uncontrolled sheet flow to the Reis Road ditch. Civil Geotechnical Structural Environmental Hydrogeology

4 Site Servicing and Storm Water Report Proposed Commercial Building Winch Holding Ltd. 128 Reis, Ottawa, Ontario Dec 10, File No REQUIRED PERMITS AND APPROVALS The proposed development is subject to the following review and approval processes: City of Ottawa Site Plan Control approval process, including review by the Mississippi Valley Conservation Authority and any other authority having jurisdiction; Part 8 OBC approval of on-site sewage treatment system design by the Ottawa Septic System Office (OSSO); Application for industrial sewage treatment (with regard to storm water runoff) by the Ontario Ministry of Environment; and The City of Ottawa Building Permit application process. 1.3 PRE-SUBMISSION CONSULTATION City of Ottawa A pre-consultation meeting was held with City of Ottawa staff on February 15, It was determined that the following civil engineering plans and reports be submitted in support of the site plan control application: Grade Control and Drainage plan; Erosion and Sediment Control plan; Servicing & Composite Utility Plan (including on-site sewage treatment). It was indicated that the criteria for stormwater flow attenuation would be to limit post-development runoff rates to that of pre-development rates associated with design storms of 5-year and 100-year return periods. It was suggested that the Mississippi Valley Conservation Authority be consulted with regard to their requirements. It was also noted that the submission would be subject to MOE industrial sewage application approval Mississippi Valley Conservation Mississippi Valley Conservation was consulted via telephone and . It was determined that an enhanced level of storm water treatment, i.e. 80% TSS removal as defined by the MOE Stormwater Manual, will be required for the site. Civil Geotechnical Structural Environmental Hydrogeology

5 Site Servicing and Storm Water Report Proposed Commercial Building Winch Holding Ltd. 128 Reis, Ottawa, Ontario Dec 10, File No REFERENCES The following references were consulted in preparation of this report: Site Plan Proposed Warehouse/Office Building, 128 Reis Rd, Carp, Ontario Ardington Design Consulting 2013 Ottawa Design Guidelines Sewer (Sewer Design Guidelines) City of Ottawa, October 2012 Stormwater Planning and Design Manual (MOE Stormwater Manual) Ontario Ministry of Environment, March 2003 Ontario Building Code Compendium (OBC) Ontario Ministry of Municipal Affairs and Housing, 2006 as amended Carp Road Corridor Community Design Plan City of Ottawa, WATER SUPPLY SERVICING 3.1 WATER SERVICING DESIGN Water is to be provided to the proposed building by means of a 150 mm diameter drilled cased well located immediately west of the proposed building. It is our understanding that hydrogeological testing was completed by others. The well location is indicated on the Site Servicing Plan, and has been considered in locating the proposed on-site sewage treatment system. 3.2 WATER SUPPLY CONCLUSIONS It is our understanding that the capacity of the existing well to service the proposed development has been evaluated as part of a hydrogeology study by others. Civil Geotechnical Structural Environmental Hydrogeology

6 Site Servicing and Storm Water Report Proposed Commercial Building Winch Holding Ltd. 128 Reis, Ottawa, Ontario Dec 10, File No WASTEWATER SERVICING 4.1 WASTEWATER DESIGN The proposed building is to be serviced by a Class 4 on-site sewage treatment system. The design for the Class 4 system was completed by Kollaard Associates Inc. and has been submitted to the Ottawa Septic System Office [OSSO]. A Certificate of Approval is pending and will be submitted to the City of Ottawa upon receipt. The proposed sewage system was designed, according to Part 8 of the OBC, to treat the design flow of domestic sewage associated with the proposed building. The system is to consist of: 3600 L septic tank; Clearstream 1000N aeration unit; Pump and chamber; and a shallow buried trench treatment field. The proposed sewage treatment system layout is indicated on the Site Servicing Plan. 4.2 WASTEWATER SERVICING CONCLUSIONS The Site Servicing and Combined Utilities Plan, as well as the On-site Sewage System design and supporting calculations submitted to the OSSO, demonstrate that the site can accommodate an onsite wastewater treatment system, designed in accordance with Part 8 of the OBC, to treat the domestic sanitary sewage flow associated with the proposed building design. 5. STORMWATER MANAGEMENT 5.1 PRE-DEVELOPMENT CONDITIONS Runoff from the site consists of uncontrolled sheet flow, over grass-covered sand, gravel and topsoil fill to the Reid Road ditch. Pre-development peak runoff rates, presented in Table 1 below, were calculated by a Rational Method analysis, using the following design parameters: Runoff coefficient, C = 0.3 to model site conditions; Time of concentration, tc = 20 min as per Sewer Design Guidelines; Storm intensity, i as per IDF equations, Sewer Design Guidelines with duration, D= tc = 20 min. Civil Geotechnical Structural Environmental Hydrogeology

7 Site Servicing and Storm Water Report Proposed Commercial Building Winch Holding Ltd. 128 Reis, Ottawa, Ontario Dec 10, File No Table 1: Summary of Pre-development Peak Runoff Rates Design Storm Peak Runoff Rate (m 3 /s) 5-year year Calculations are presented as an appendix to this report. 5.2 POST-DEVELOPMENT STORMWATER MANAGEMENT DESIGN CRITERIA In consultation with the City of Ottawa and the Mississippi Valley Conservation Authority, it was determined that the stormwater management system is to be designed according to the following criteria: Runoff from 5-year and 100-year design storms to be attenuated to pre-development rates; Release rate from storage to be restricted to runoff rate associated with 5-year design storm; Enhanced level of treatment (80% TSS removal) of runoff from parking lot and laneway. 5.3 PROPOSED STORMWATER MANAGEMENT SYSTEM The stormwater management design consists of site grading directing runoff to a grassed swale between the building and the west property line. Storage is to be provided within the swale and in the rear parking lot. The swale has been designed for water quality treatment following the MOE Stormwater Manual. A sand filter, protected from erosion by rip rap, is to be constructed within the swale, at the outlet to the roadside ditch. The filter will serve to provide additional stormwater treatment (by filtration and settling). Should the filter fail, a volume in excess of the water quality storage requirement would be expected to infiltrate in the swale. A catchbasin is to be installed at the end of the swale. The catchbasin lead is to be with a plate orifice inlet control device to control the discharge rates associated with 5-year to 100-year storm events. Runoff from site The proposed stormwater management system is to collect, store and control runoff from the roof, parking lot, laneway and much of the landscaped area of the site. Civil Geotechnical Structural Environmental Hydrogeology

8 Site Servicing and Storm Water Report Proposed Commercial Building Winch Holding Ltd. 128 Reis, Ottawa, Ontario Dec 10, File No Due to practical site grading constraints, not all of the runoff from the site can be controlled by the stormwater management system. Stormwater runoff from the surface of the sewage treatment bed is to be drained by sheet flow to the roadside ditch. The controlled and uncontrolled areas are shown in Figure 2. Runoff rates from controlled and uncontrolled areas were determined based on a rational method analysis presented as an appendix to this report. Runoff from uncontrolled areas was accounted for in the calculation of allowable release rates from storage. Offsite drainage The subject site is to share a laneway with the neighbouring property owned by Winch Holdings. Under existing conditions, runoff from the laneway drains uncontrolled to the Reis Road ditch. It is proposed to collect and control the runoff from the shared laneway in the stormwater management system. Impervious Ratio The impervious ratio, the total impervious area divided by the total area, is about 77.4 percent for entire area (the site and offsite areas contributing runoff). Post-development runoff coefficients Runoff coefficients, used in the rational method analysis, were calculated as a weighted average (by area) as indicated in Table 2. Table 2: Post Development Runoff Coefficients Description 5 year- Runoff Coefficient 100-year Runoff Coefficient Area m 2 Area ha TOTAL SITE AREA OFF SITE AREA CONTRIBUTING RUNOFF 433 TOTAL DEVELOPED AREA Total Building Area 415 Controlled Building Areas Uncontrolled Building Areas Total Landscape Area (Grass, Shrub, Tree, Pond) Controlled Landscape Area Uncontrolled Landscape Area Civil Geotechnical Structural Environmental Hydrogeology

9 Site Servicing and Storm Water Report Proposed Commercial Building Winch Holding Ltd. 128 Reis, Ottawa, Ontario Dec 10, File No Total Asphalt & Gravel - Parking & Roadways Controlled Asphalt Controlled Gravel Uncontrolled Gravel Uncontrolled Asphalt Controlled Area Weighted Avg. C Uncontrolled Area Weighted Avg. C Storage and Release Rates A catchbasin is to be installed at the downstream end of the swale. The lead from the catchbasin is to be equipped with a 4 plate orifice inlet control device (ICD) to control discharge rates. Release rates and storage requirements for 5-year and 100-year storm events are summarized in Table 3. Calculations are presented as an appendix to this report. Table 3: Release rates and storage requirements Design Release Storage Elevation Runoff Rate Expected Total Allowable Storm Rate Required of Top of from Runoff Runoff Rate from Storage Uncontrolled Rate from Site From Site Storage Areas (from Table 2) m 3 /s m 3 m m 3 /s m 3 /s m 3 /s 5-year year As indicated on the Grading and Erosion Control Plan, the required storage can be accommodated on site. Note: A vertical sand filter is to be installed at the end of the swale, as indicated on the engineering drawings. According to MVCA, the seepage rate through a sand filter is to be calculated using the Darcy equation, with a coefficient of permeability equal to 45 mm/min = 1.25 x 10-5 m 3 /s. Using this design permeability, the flow rate through the sand would be insignificant compared to the flow rate through the ICD. For example, at a ponding elevation of , the flow rate through the sand filter would be: Civil Geotechnical Structural Environmental Hydrogeology

10 Site Servicing and Storm Water Report Proposed Commercial Building Winch Holding Ltd. 128 Reis, Ottawa, Ontario Dec 10, File No Ak( h + d) Q = d Where A = cross-sectional area of filter = 1.68 m 2. k =coefficient of permeability = 1.25 x 10-5 m 3 /s h = head across filter = ( )/2 = 0.20 m d = thickness of filter = m Q = 2.4 x 10-5 m 3 /s. This flow rate is not significant compared to the 1.1x 10-2 m 3 /s flow through the ICD. 5.4 STORM WATER QUALITY CONTROL The exterior portions of the site are to be used for vehicle parking and building access. No business shall be carried out that will adversely affect waterways and their habitats. The Reis Road ditch discharges into a municipal drain that is tributary to the Huntley Creek. Preconsultation with MVCA determined that an enhanced level of treatment is required. Enhanced treatment is defined by the Ministry of Environment, Stormwater Management Planning and Design Manual (MOE Stormwater Manual) as long-term average removal of 80% of suspended solids. The required water quality storage volume was determined according to MOE Stormwater Manual Table 3.2. The stormwater management system was designed such that the storage volume provided in the swale and parking area below the level of the catchbasin inlet exceeds the water quality storage requirement. Water quality storage volumes are listed in Table 4. Table 4: Water Quality Storage MOE Water Quality Required Water Water Quality Elevation of Top of Storage Criteria Quality Storage Storage Water Quality Provided in Design Storage m 3 /ha m 3 m 3 m Part 4 of the MOE Stormwater Manual describes grassed swales to remove suspended solids from storm water. The approximately 80 m long grassed swale that is to be constructed along the Civil Geotechnical Structural Environmental Hydrogeology

11 Site Servicing and Storm Water Report Proposed Commercial Building Winch Holding Ltd. 128 Reis, Ottawa, Ontario Dec 10, File No west property line has been designed in accordance with the guidelines set forth in the MOE manual. Additional treatment is to be provided by a vertical sand filter is to be constructed at the downstream end of the swale. Should the sand filter become clogged, calculations indicate that there is adequate surface area within the swale to allow infiltration of the water quality storage volume. The filter was designed such that stormwater runoff ponding to the elevation of the water quality storage will be filtered through a minimum 0.50 m of sand. This corresponds to the depth of sand deemed to provide enhanced treatment in the MOE manual. Details for the proposed swale and filter design are shown on Kollaard Associates Inc. drawing GP. A design summary of the swale is presented in Table 5. Table 5: Design Summary - Grassed Swale Parameter Provided in Design MOE Criteria Design Storm 2yr (34 mm), 4hr > 25 mm, 4hr ( Chicago hyetograph) Peak flow rate in swale 0.02 < 0.15 max during design storm (m 3 /s) Maximum velocity during 0.35 < 0.5 max design storm (m/s) Bottom Slope (%) 0.35 < 4 max Grass height (mm) 75 = 75 Water quality storage 8 = 8 Time for water quality storage to infiltrate <7 hrs Civil Geotechnical Structural Environmental Hydrogeology

12 Site Servicing and Storm Water Report Proposed Commercial Building Winch Holding Ltd. 128 Reis, Ottawa, Ontario Dec 10, File No Maintenance Grass in the swale should be maintained at a height of no less than 75mm (3 inches). Removal of accumulated sediment from the grass pre-treatment buffer should be conducted when the accumulation of the sediment begins to significantly affect the growth of grass and/or the drainage patterns over the grass buffer. Silt/sediment should be removed from the surface of the filter when 2-3 cm has accumulated or if ponding is observed in the swale more than 30 hours after the end of a rainfall event. The upper layer of the filter material (e.g., 0.1 to 0.15 m) should be removed and replaced with clear material when accumulated sediment is removed from the filter. 5.5 STORMWATER SERVICING CONCLUSIONS The proposed stormwater management system conforms to the design objectives: Design discharge rates are limited to predevelopment conditions. The site will accommodate the required stormwater storage volumes. The system is designed for enhanced water quality treatment. 6. SEDIMENT AND EROSION CONTROL In order to limit the amount of sediment carried in stormwater runoff from the site during construction, it is recommended to install a silt fence at the location indicated on the Grading and Erosion Control Pan. The silt fence may be polypropylene, nylon, polyester or ethylene yarn. If a standard filter fabric is used, it must be backed by a wire fence supported on posts not over 2.0 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. Civil Geotechnical Structural Environmental Hydrogeology

13 Site Servicing and Storm Water Report Proposed Commercial Building Winch Holding Ltd. 128 Reis, Ottawa, Ontario Dec 10, File No The grassed swale is to be lined with an erosion control blanket such as the Terrafix S100 erosion control blanket. The exposed landscaped areas of the site should be seeded with a rapid growing grass mixture as soon as possible. The proposed 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. The contractor shall implement best management practices, to provide for protection of the area of the drainage system and the receiving watercourse, during construction activities. 7. UTILITIES Hydro, telephone, cable and gas are available along the Reis Road corridor and will be installed according to the requirements of respective utility companies. 8. CONCLUSION This report has been prepared on behalf of Winch Holding Ltd. in support of an application to the City of Ottawa for site plan approval of a proposed warehouse/office and associated parking lot to be constructed at 128 Reis Road, Carp. Conclusions drawn from the report are as follows: There is an existing well on site. The suitability of the well to service the proposed development is to be assessed by others. Wastewater servicing is to be provided by means of a class 4 on-site sewage treatment system consisting of a septic tank, Clearstream aeration unit, pump chamber and shallow buried trench treatment field. A detailed design has been prepared and application for approval is to be made to the Ottawa Septic System Office. The proposed site stormwater management system has been designed to meet the runoff flow attenuation and water quality objectives set out by the City of Ottawa and Mississippi Valley Conservation in pre-application consultation. Civil Geotechnical Structural Environmental Hydrogeology

14 Site Servicing and Storm Water Report Proposed Commercial Building Winch Holding Ltd. 128 Reis, Ottawa, Ontario Dec 10, File No Hydro, telephone, cable and gas are available along the Reis Road corridor and will be installed according to the requirements of respective utility companies. Best management practices with regard to erosion and sediment controls are to be implemented to provide for protection of the site and receiving watercourse during construction. The report is to be read in conjunction with the Kollaard Associates drawings listed below. Prepared by, Kollaard Associates Inc. Per: Ian Malcolm, P.Eng. Kollaard Associates, Inc. Related Drawings: GR Grading and Erosion Control Plan SS Site Servicing Plan SD Septic Design and Details Civil Geotechnical Structural Environmental Hydrogeology

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17 Dec 10, 2013 Site Servicing and Storm Water Report 128 Reis Rd File APPENDIX A STORMWATER MANAGEMENT - RATIONAL METHOD ALLOWABLE CONTROLLED AREA RELEASE RATE Civil Geotechnical Structural Environmental Hydrogeology

18 APPENDIX A: STORMWATER MANAGEMENT MODEL RATIONAL METHOD CALCULATION SHEET - ALLOWABLE CONTROLLED AREA RELEASE RATE Client: Winch Holding Ltd. Job No.: Location: 128 Reis Road, Carp, City of Ottawa, Ontario Date: December 10, 2013 Design Criteria: TOTAL AREA hectares Controlled hectares Uncontrolled hectares impervious ratio Pre-Development Time of Concentration, (Pre) Tc = 20 minutes Pre-Development C = 0.30 Post-Development 5 - Yr Post-Development C (Controlled)= Yr Post-Development C (Uncontrolled)= Yr Post-Development C (Controlled)= Yr Post-Development C (Uncontrolled)= 0.38 Time of Concentration, (Post) Tc = 10 minutes 5 YEAR STORM I = mm/hr CALCULATED OUTFLOW RESTRICTION = m 3 /s 100 YEAR STORM I = mm/hr CALCULATED OUTFLOW RESTRICTION = m 3 /s 5 YEAR STORM RUNOFF EVENT ALLOWABLE CONTROLLED AREA RELEASE RATE CALCULATION PRE-DEVELOPMENT POST-DEVELOPMENT ALLOWABLE RAINFALL RAINFALL PEAK CONTROLLED UNCONTROLLED CONTROLLED AREA DURATION INTENSITY RUNOFF PEAK RUNOFF PEAK RUNOFF RELEASE RATE (min.) (mm/hr) (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 100 YEAR STORM RUNOFF EVENT ALLOWABLE CONTROLLED AREA RELEASE RATE CALCULATION PRE-DEVELOPMENT POST-DEVELOPMENT ALLOWABLE RAINFALL RAINFALL PEAK CONTROLLED UNCONTROLLED CONTROLLED AREA DURATION INTENSITY RUNOFF PEAK RUNOFF PEAK RUNOFF RELEASE RATE (min.) (mm/hr) (m 3 /s) (m 3 /s) (m 3 /s) m 3 /s 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

19 Dec 10, 2013 Site Servicing and Storm Water Report 128 Reis Rd File APPENDIX B STORAGE VOLUME AND DISCHARGE RATES Civil Geotechnical Structural Environmental Hydrogeology

20 APPENDIX B: STORMWATER MANAGEMENT MODEL STORAGE VOLUME AND DISCHARGE RATE Kollaard Associates Inc. Client: Winch Holding Ltd. Job No.: top of sand Location: 128 Reis Road, Carp, City of Ottawa, Ontario orifice diameter 0.1 top of weir centre of orifice weir coefficient 1.57 area of orifice Length of weir 3 coefficient 0.67 top of slope Date: December 10, 2013 Note: - Pond details as shown on drawing GR Elevation Layer Top Bottom Layer Cumulative Depth Head Discharge Head on Discharge Head Discharge Total Total Depth Layer Layer Volume Volume of On orifice 1 through Rip Rap through over weir over Discharge Discharge Area Area Storage orifice 1 Rip Rap weir n m m m 2 m 2 m 3 m 3 m m m 3 /s m m 3 /s m m 3 /s m 3 /s L/s Column Column 1 Elevation n Column 12 Elevation n - Elevation of Top of Weir Column 2 Elevation n - Elevation n-1 Column 13 Flow calculated by weir equaq = 1.57 x L x H 1.5 Column 3 Surface area of storage at Elevation n Column 14 Column 9 + Column 11 Column 4 Surface area of storage at Elevation n-1 Column 15 Column 12 x 1000 L / m 3 Column 5 Storage volume between Elevation n and Elevation n-1 Column 6 Storage volume between Elevation n and bottom Column 7 Elevation n - Bottom Elevation Column 8 Elevation n - Elevation of Centre of Orifice Column 9 Flow calculated by orifice equation Column 10 Elevation n - Elevation of bottom of rip rap Column 11 Flow calculated by Darcy equation with k = 0.01 to model rip rap h = average head on rip rap d= thickness of media Q = C*A*sqrt(2*g*H) Ak ( h + d ) Q = d Note: Flow rate through sand using k = 45min/cm = m/s is three orders of magnitude slower than the flow rate through the orifice and is therefore not significant with regard to storage calculations.

21 Dec 10, 2013 Site Servicing and Storm Water Report 128 Reis Rd File APPENDIX C STORMWATER MANAGEMENT DESIGN DISCHARGE RATE AND STORAGE VOLUME REQUIREMENTS Civil Geotechnical Structural Environmental Hydrogeology

22 Client: RATIONAL METHOD CALCULATION SHEET - REQUIRED STORAGE AND RELEASE RATE Winch Holding Ltd. Job No.: Location: 128 Reis Road, Carp, City of Ottawa, Ontario Date: 28-Nov-13 APPENDIX C: STORMWATER MANAGEMENT MODEL Design Criteria: Total Area contributing runoff from site hectares Stormwater Quality Treatment Method Total Controlled Area hectares Sand Filter Total Uncontrolled Area from Site hectares Quality Storage Requirement = Impervious ratio m 3 /ha = 8.1 See Storm Water Design Report Pre-Development Pre-Development C = 0.30 Maximum Allowable Release Rate 5 year Storm Event Post-Development (m 3 /s) 5 - Yr Post-Development C (Controlled)= 0.61 Maximum Allowable Release Rate 100 year Storm Event 5 - Yr Post-Development C (Uncontrolled)= (m 3 /s) Yr Post-Development C (Controlled)= Yr Post-Development C (Uncontrolled)= 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 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 47.4 Column

23 Column 1 Storm duration under consideration Column 2 Intensity calculated by City of Ottawa IDF equation for storm duration under consideration Column 3 Q = CIA where C and A correspond to pre-development conditions Column 4 Column 1 x Column 3 x 60s/min Column 5 Q = CIA where C and A correspond to areas of uncontrolled runoff Column 6 Q = CIA where C and A correspond to areas of controlled runoff Column 7 Release rate from storage calculated in Appendix C corresponding to storage volume indicated in Column 8 Column 8 Column 9 (Column 6 - Column 7) x Column 1 x 60 s/min Column 5 + Column 8 For 5-year storms i = ( ) t c For 100-year storms i = ( ) t c

24 Dec 10, 2013 Site Servicing and Storm Water Report 128 Reis Rd File APPENDIX D GRASSED SWALE DESIGN Civil Geotechnical Structural Environmental Hydrogeology

25 Peak intensity of precipitation associated with a design storm modelled as a Chicago Hyetograph Method The Chicago Hyetograph is a model of storm intensity vs time derived from Intensity-Frequency-Duration (IDF) curves of the format: i = a eqn 1 [t + c] b where i = average intensity of storm over duration under consideration (mm/hr) t= time (minutes) a,b,c = constants developed for each IDF curve based on statistical analysis of local storm data The intensity of a storm varies over its duration. The Chicago Hyetograph may be calculated in terms of the time elapsed before and after peak intensity occurs, by the following equations: Before the peak: After the peak: where i b i a = a[{1 - b}{tb / r} + c] [tb / r + c] 1 + b a[{1 - b}{ta / (1 - r)} + c] = [ta / {1 - r} + c] 1 + b ia = intensity after peak ib = intensity before peak ta = time after peak tb = time before peak r = ratio of time elapsed at peak intensity to storm duration (As published in Modern Sewage Design, 4th Edition, American Iron and Steel Institute, 1999)

26 Calculations IDF curve of storm event under consideration The model storm to be considered in the design of a grassed swale is to have the following characteristics: Storm duration = 4 hr (MOE Manual) Minimum precipitation (over duration 25 mm of storm) Consider a design storm of two year return period. The City of Ottawa IDF curve constants are: a = b = 0.81 (City of Ottawa Sewer Design Guidelines) c = Substituting these constants into the IDF eqn with t= 240 min yields i = mm/hr The total precipitation over the duration of the storm is: P = (i) x (duration) = mm = a [t + c] b A two-year four-hour storm results in a total preciptation of more than 25 mm. Since there are no data available for storms of shorter return periods, the two year four hour storm has been considered in the design of the grassed filter.

27 Peak Intensity according to Chicago Hyteograph In Ontario, the ratio of time to peak over storm duration has been reported as: r= (Otthymo Manual) Therefore, the instantaneous peak intensity for the storm under consideration would occur after an elapsed time of: tp = (r) x (duration) = 1.95 hr = min To calculate total precipitation, hyetographs are typically divided into intervals (time steps ), with a constant intensity considered over each interval. The time step considered in the present analysis is: time step = 10 min (as per City of Ottawa Sewer Design Guidelines ) The peak time step has been considered to occur at a time before the peak of: tb = (r) x (time step) tb = 4.88 minutes before peak The end of the peak time step therefore occurs at ta = 5.12 after the peak intensity occurs This corresponds to an elapsed time of: to minutes from start of storm The intensity during the peak time step is calculated by eqn 2 of this appendix as: or by eqn 3 as: i a[{1 - b}{tb / r} + c] b = = mm/hr [tb / r + c] 1 + b a[{1 - b}{ta / (1 - r)} + c] i a = [ta / {1 - r} + c] 1 + b = mm/hr The peak intensity of precipitation of a 4 hr Chicago storm producing at least 25 mm of precipitation is: i peak = mm/hr over a time step of: 10 min

28 Infiltration versus time based on the Horton Infiltration Equation The Horton equation models the decay of infiltration over time as follows: F = fc+(f 0 -f c )e -kt where F = infiltration at time 't', mm/hr fc = final infiltration rate, mm/hr F 0 = initial infiltration rate, mm/hr k= a decay constant In the present analysis, infiltration was calculated with the following parameters: fc = 13.2 mm/hr (as per City of Ottawa Sewer Design Guidelines ) F 0 = 76.2 mm/hr (as per City of Ottawa Sewer Design Guidelines ) k= s -1 (as per City of Ottawa Sewer Design Guidelines ) t = min (time to peak of Chicago Hyetograph) The infiltration at the peak of the storm intensity is therefore calculated as: t= s e= kt= e -kt = F= mm/hr

29 Net runoff based on calculated rainfall intensity and infiltration rate In the present analysis it has been assumed that at the peak intensity of the storm, the initial abstraction (depression storage etc.) has been exhausted so that: Peak runoff rate from vegetated surfaces = Intensity-Infiltration rate Peak runoff rate from impermeable surfaces = Intensity of precipitation Intensity of precipitation mm/hr (Peak of 4 hr Chicago storm) Infiltration rate mm/hr ( Horton eqn for t = peak intensity) Peak unit runoff rate from vegetated areas mm/hr (precipitation- infiltration) Catchment Area 0.22 ha Impervious ratio 0.77 Peak runoff rate from vegetated areas m 3 /s (unit runoff x vegetated area) Peak runoff rate from impervious surfaces m 3 /s (precip x impervious area) Peak runoff rate m 3 /s

30 Velocity and depth of flow in a grassed swale for a given flow rate Peak Flow rate 1 m 3 /s Q= m 3 /s Swale dimensions Bottom width m b = 0 Side slopes horiz/vert m/m m = 3 Bottom slope m/m S = Manning roughness n = Cross section area m 2 Ax= = (b + my)y Wetted perimeter m P = Hydraulic radius m R = = b + 2y(1 + m 2 ) 0.5 = Ax / P Depth of flow m y = Velocity m/s V= Manning flow rate 2 m 3 /s Q = = Q / Ax = 1 / naxr 2 / 3 S 1 / 2 (1) Peak runoff rate associated with 4 hr, two-year Chicago hyetograph (2) Flow rate in swale calculated by Manning equation for flow depth 'y' Depth of flow, 'y' was iterated until the flow rate calculated by the Manning equation converged with the runoff rate of the 2yr 4-hr Chicago storm.

31 Percolation and Drawdown of Water Quality Storage Note: These calculations are provided to indicate that if the proposed sand filter were to clog, the stored stormwater would be considered to infiltrate in a reasonable amount of time. Method The rate of percolation of stored water is calculated according to the method suggested in the MOE Manual for grassed swales, as follows: where: Q perc = Percolation rate, m 3 /s P Q perc = f (MOE Manual eq'n 4.20) L Wn L W = approximate wetted area of storage, m 2 f= Longevity factor n= Porosity P= Unit percolation, mm/hr The percolation rate was used to estimate the time that would be required for the water quality storage to infiltrate: t= V/Q perc where: V= Water quality storage volume, m 3 Calculations V = L W = 8.1 (water quality storage) 95 (wetted area approximated from drawing) P = 13.2 (City of Ottawa sewer design manual, default value for final infiltration rate, this is a conservative estimate for this soil) f = 1 (MOE Manual, value for grass swale) n = 1 (MOE Manual, value for grass swale) Q perc = = f P L Wn t= seconds t= 6.5 hrs

32 Summary of Grassed Swale Design for Water Quality Treatment Provided in Design MOE Criteria Design Storm for treatment in grassed swale 2 yr, 4 hr 25 mm 4hr Total Precipitation of Design Storm (mm) > 25 min Peak flow rate in swale for Chicago Storm (m 3 /s) < 0.15 max Maximum velocity (m/s) < 0.5 max Bottom slope 0.35% < 4% max Grass Height > 75 > 75 max Water quality storage (m3) Time for water quality storage to infiltrate < 7 hrs

33 Dec 10, 2013 Site Servicing and Storm Water Report 128 Reis Rd File APPENDIX E RESPONSE TO MVCA COMMENTS Civil Geotechnical Structural Environmental Hydrogeology

34 Civil Geotechnical Structural Environmental Materials Testing 210 Prescott Street, Unit 1 (613) P.O. Box 189 Kemptville, Ontario K0G 1J0 FAX: (613) Justyna Garbos City of Ottawa Planning & Growth Management Development Review Rural Services 110 Laurier Avenue West, 4th Floor Ottawa, ON, K1P 1J1 E: Justyna.Garbos@ottawa.ca Re: Site Plan Control application D This letter has been prepared in response to issues identified for clarification by the Mississippi Valley Conservation Authority (MVCA) in its review of documents prepared by Kollaard Associates in support of an application for site plan control for the above-noted project. For each of the issues raised by the MVCA, presented in italics, a response is given below. General comment by MVCA - MVCA expects the sand filter will clog within a relatively short amount of time and will not perform as expected. However the system is still expected to provide the required quality control. The grassed swale will provide some treatment and a portion of the ponded water is expected to infiltrate into the existing sandy soils. In light of the opinion offered by MVCA, an outlet control structure (catchbasin with ICD) has been added at the downstream end of the grassed swale, to control the release rates of the 5-year and 100- year storm storage volumes. The release rates would therefore not be dependent on the flow rate through the sand. Treatment would be provided by a combination of flow through the grassed swale and infiltration, as deemed adequate by MVCA. The velocity of flow through the swale has been limited to 0.5 m/s during the peak flow of a 4 hr 25 mm Chicago storm, as per MOE design guidelines for treatment in grassed swales. The surface of the storage area is considered adequate to allow infiltration of the water quality storage volume. Supporting calculations have been included as appendices to the revised stormwater report. 1. It is not clear if off-site flows from the west corner of the site have been considered. Grades at the west corner (i.e. left rear corner) of the property were found to be generally higher than those found on neighbouring properties. The drainage pattern was therefore considered to be generally away from the rear left corner of the subject property. Refer to figure 1 of this letter. 2. MVCA cannot replicate the actual storage release rate values from Appendix C. Release rates in Appendix C correspond to the total discharge rates calculated in Appendix B for equivalent storage volumes. Discharge was originally calculated by the Darcy equation with k = m/s to model flow through the filter sand (k value corresponding to the specified sand with T Professional Engineers Ontario Authorized by the Association of Professional Engineers of Ontario to offer professional engineering services.

35 Page 2 = 2 mins/cm). In subsequent correspondence, MVCA indicated that the value of k=45 mm/hr be used in the design calculations. This slower design flow rate through the sand would make it impractical to consider the filter as the control mechanism for the storage release rates (the resulting storage volumes cannot be accommodated). A catchbasin with an inlet control device (ICD) has therefore been added at the downstream end of the swale. 3. MVCA recommends the geotextile extend to underneath the sand filter to protect the toe of the sand filter from piping. The drawings have been revised to indicate the geotextile extending underneath the sand filter. 4. The sediment and erosion control plan requires the following details: a. The silt fence must be installed such that it prevents sediment from entering the grassed swale and discharging from the site. b. Erosion control is required within the realigned watercourse. The drawings have been revised to indicate the silt fence extended along the east side of the swale. The swale is to be protected from erosion by installation of an erosion blanket. 5. The proposed ponding area may not be permitted to extend to the existing well and should be verified. The ground surface around the well is to be graded such that there is positive drainage away from the well. We trust that this letter responds to your current requirements. Prepared by: Kollaaard Associates, Engineers Per: Ian Malcolm, P.Eng. Civil Geotechnical Structural Environmental Industrial Health & Safety

36 Dec 10, 2013 Site Servicing and Storm Water Report 128 Reis Rd File APPENDIX F RESPONSE TO CITY OF OTTAWA COMMENTS Civil Geotechnical Structural Environmental Hydrogeology

37 Civil Geotechnical Structural Environmental Materials Testing 210 Prescott Street, Unit 1 (613) P.O. Box 189 Kemptville, Ontario K0G 1J0 FAX: (613) Kollaard File # Page 1 December 10, 2013 To: Justyna Garbos City of Ottawa Planning & Growth Management Development Review Rural Services 110 Laurier Avenue West, 4th Floor Ottawa, ON, K1P 1J1 E: Justyna.Garbos@ottawa.ca T: ext F: Re: Site Plan Control application D Proposed Light Industrial Building, Reis Road, Ottawa, Ontario The following Circulation Comments dated November, 2013 were provided. Kollaard Associates Inc.'s response is provided in italics immediately after each comment for clarity: Engineering Comments: Brian Morgan, Project Manager, Infrastructure Approvals (Servicing) Jeff McEwen, Program Manager, Development Review, Rural Services Well City : How far is the proposed well from the property line? It should be a minimum of 3.0 metres away Kollaard: The existing well casing was measured as 2.97 m from the property line. It is our understanding that the purpose of the 3 m setback is to ensure that any future re-grading of the neighbouring property would not divert runoff toward the well. In this case, there is a swale between the property line and the existing well, so that re-grading of the neighbouring property would not affect the well. City : Please include a dimension showing that the well is a minimum of 15.0 metres from the edge of the septic mantle Kollaard:The dimension shown on the septic system plan has been added to the site servicing plan. City : Current well location is at the top of the slope of the storm pond. Wells should never be placed in a situation where the base of the casing could be flooded. Please revise the grading around the well to ensure that there will always be positive drainage away from the well or relocate the well. Professional Engineers Ontario Authorized by the Association of Professional Engineers of Ontario to offer professional engineering services.

38 Response to Site Plan Control Application City of Ottawa File D Circulation Comments Page 2 You will need to regrade or relocate the well out of the swale/storm pond (see O. Reg. 903, Section 12.3) Kollaard: The well is located at the top of the proposed berm of the proposed swale, above the 100- year storage level. The drawings has been revised to clarify positive grading around the well. Grading and Erosion Control Plan City : Show 5 and 100 year flood elevations on all the sections Kollaard: The 5-yr and 100-yr storage elevations shown on the plan have been added to the sections. City : Section E shows the top of the berm at elevation This means that the top of the berm is only 0.1 metres above the 100-year flood line (115.40). The City requires at least 0.3 metres freeboard. Kollaard: The proposed elevations of the top of swale have been revised to show 0.3 m of freeboard above the 100-yr storage level. City : Where does the clay berm start and end? Please confirm that the clay berm extends the full length of the septic bed. Kollaard: The clay berm is to extend the length of the septic system, as approved by the Ottawa Septic System Office. City : A silt fence is required along the southern property line Kollaard: A silt fence has been added along the southern propery line. Septic Design and Details City :Amend R-16 to show R-15 around the existing well Kollaard: The drawing has been amended to show a radius of 15 m instead of 16 m around the neighbouring well. City :There should be test pits under the building Kollaard:Septic test pits are generally put down in the area of the proposed infiltration bed. It is common practice to avoid putting test pits down in the area of the proposed building to avoid compromising areas of the subgrade beneath the building. Stormwater Report City: Does the report take into account flow or seepage through the clay berm? Kollaard: The rate of seepage through the clay berm is considered insignificant as the coefiicient of permeability of the clay would be three or four orders of magnitude smaller than that of the imported sand or native material. Civil Geotechnical Structural Environmental Industrial Health & Safety

39 Response to Site Plan Control Application City of Ottawa File D Circulation Comments Page 3 City: Does the report take into account flow or seepage through the sand weir? Kollaard: The rate of flow through the sand filter was calculated according to the Darcy formula using a typical value for the coefficient of permeability. Note that in its review, the MVCA expressed an opinion that a slower flow rate be considered through the sand filter. The outlet control has been subsequently revised to include catchbasin and pipe with an inlter control device (ICD). We trust that this response provides sufficient information for your present purposes. If you have any questions concerning this response or if we can be of any further assistance to you on this project, please do not hesitate to contact our office. Sincerely, Ian Malcolm, P.Eng. Kollaard Associates Inc Civil Geotechnical Structural Environmental Industrial Health & Safety