FUNCTIONAL SERVICING AND STORM WATER …

Civil • Geotechnical •

Structural • Environmental

210 Prescott Street, Unit 1 (613) 860-0923

P.O. Box 189 Kemptville, Ontario K0G 1J0 FAX: (613) 258-0475

Professional Engineers

Ontario

Authorized by the Association of Professional Engineers of Ontario to offer professional engineering services.

FUNCTIONAL SERVICING AND STORM WATER MANAGEMENT STUDY

PROPOSED COMMERCIAL BUILDING

128 REIS ROAD, CARP CITY OF OTTAWA, ONTARIO

PREPARED FOR:

Winch Holding Ltd. 1559 Landel Drive

Ottawa, ON

PROJECT # 130038

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

Site Servicing and Storm Water Report – Proposed Commercial Building

Winch Holding Ltd. 128 Reis, Ottawa, Ontario

Dec 10, 2013 ─ 2 ─ File No. 130038

Civil • Geotechnical • Structural • Environmental • Hydrogeology

Table of Contents

1. Introduction .................................................................................................................................................. 3

1.1 Existing Site Conditions .......................................................................................................................... 3

1.2 Required Permits and Approvals ............................................................................................................ 4

1.3 Pre-submission consultation ................................................................................................................... 4

1.3.1 City of Ottawa ............................................................................................................... 4

1.3.2 Mississippi Valley Conservation .................................................................................... 4

2. References .................................................................................................................................................. 5

3. Water Supply Servicing ............................................................................................................................... 5

3.1 Water Servicing Design........................................................................................................................... 5

3.2 Water supply Conclusions....................................................................................................................... 5

4. Wastewater Servicing .................................................................................................................................. 6

4.1 Wastewater Design ................................................................................................................................. 6

4.2 Wastewater Servicing Conclusions ......................................................................................................... 6

5. Stormwater Management ............................................................................................................................ 6

5.1 Pre-development conditions ................................................................................................................... 6

5.2 Post-development Stormwater Management Design Criteria ................................................................. 7

5.3 Proposed StormWater Management System ......................................................................................... 7

5.4 Storm Water Quality Control .................................................................................................................10

5.5 Stormwater Servicing Conclusions .......................................................................................................12

6. Sediment and Erosion Control ..................................................................................................................12

7. Utilities .......................................................................................................................................................13

8. Conclusion .................................................................................................................................................13

Figure 1 Key Plan

Figure 2 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

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Appendices E and F

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Responses to MVA and City of Ottawa Comments to original submission



Dec 10, 2013 ─ 3 ─ File No. 130038


1. 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 m2 in

building area, which is to include approximately 150 m2 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.



Dec 10, 2013 ─ 4 ─ File No. 130038


1.2 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

1.3.1 City of Ottawa

A pre-consultation meeting was held with City of Ottawa staff on February 15, 2013. 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.

1.3.2 Mississippi Valley Conservation

Mississippi Valley Conservation was consulted via telephone and email. 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.



Dec 10, 2013 ─ 5 ─ File No. 130038


2. 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, 2004

3. 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.



Dec 10, 2013 ─ 6 ─ File No. 130038


4. 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.



Dec 10, 2013 ─ 7 ─ File No. 130038


Table 1: Summary of Pre-development Peak Runoff Rates

Design Storm Peak Runoff Rate (m3/s)

5-year 0.014

100-year 0.024

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.

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equipped



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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

m2

Area ha

TOTAL SITE AREA 1927 0.193

OFF SITE AREA CONTRIBUTING RUNOFF 433

TOTAL DEVELOPED AREA 2360 0.236

Total Building Area 415

Controlled Building Areas 0.9 1 415 0.042

Uncontrolled Building Areas 0.9 1 0 0.000

Total Landscape Area (Grass, Shrub, Tree, Pond) 0 875

Controlled Landscape Area 0.3 0.375 690 0.069

Uncontrolled Landscape Area 0.3 0.375 185 0.019



Dec 10, 2013 ─ 9 ─ File No. 130038


Total Asphalt & Gravel - Parking & Roadways 0 1048

Controlled Asphalt 0.9 1 0 0.000

Controlled Gravel 0.7 0.875 1077 0.108

Uncontrolled Gravel 0.7 0.875 0 0.000

Uncontrolled Asphalt 0.9 1 0 0.000

Controlled Area Weighted Avg. C 0.61 0.74

Uncontrolled Area Weighted Avg. C 0.30 0.38

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

Storm

Release

Rate

from

Storage

m3/s

Storage

Required

m3

Elevation

of Top of

Storage

m

Runoff Rate

from

Uncontrolled

Areas

m3/s

Expected Total

Runoff

Rate from Site

m3/s

Allowable

Runoff Rate

From Site

(from Table 2)

m3/s

5-year 0.011 18.0 115.30 0.001 0.013 0.014

100-year 0.015 47.4 115.40 0.002 0.018 0.024

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 m3/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 115.30, the flow rate through the sand filter would be:



Dec 10, 2013 ─ 10 ─ File No. 130038


Where A = cross-sectional area of filter = 1.68 m2.

k =coefficient of permeability = 1.25 x 10-5 m3/s

h = head across filter = (115.30-114.90)/2 = 0.20 m

d = thickness of filter = 1.375 m

Q = 2.4 x 10-5 m3/s.

This flow rate is not significant compared to the 1.1x 10-2 m3/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

Storage Criteria

m3/ha

Required Water

Quality Storage

m3

Water Quality

Storage

Provided in Design

m3

Elevation of Top of

Water Quality

Storage

m

37 8 8 115.15

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

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Dec 10, 2013 ─ 11 ─ File No. 130038


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

130038-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

( Chicago hyetograph)

2yr (34 mm), 4hr > 25 mm, 4hr

Peak flow rate in swale

during design storm

(m3/s)

0.02 < 0.15 max

Maximum velocity during

design storm (m/s)

0.35 < 0.5 max

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



Dec 10, 2013 ─ 12 ─ File No. 130038


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.



Dec 10, 2013 ─ 13 ─ File No. 130038


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.



Dec 10, 2013 ─ 14 ─ File No. 130038


• 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:

130038-GR Grading and Erosion Control Plan

130038-SS Site Servicing Plan

130038-SD Septic Design and Details

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2013.12.10

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KEYPLAN

Dec 10, 2013 Site Servicing and Storm Water Report

128 Reis Rd File 130038


APPENDIX A

STORMWATER MANAGEMENT - RATIONAL METHOD

ALLOWABLE CONTROLLED AREA RELEASE RATE

Client: Winch Holding Ltd.

Job No.: 130038

Location: 128 Reis Road, Carp, City of Ottawa, Ontario

Date:

Design Criteria:

TOTAL AREA 0.237 hectares

Controlled 0.218 hectares

Uncontrolled 0.019 hectares

0.774 impervious ratio

Pre-Development

Time of Concentration, (Pre) Tc = 20 minutes

Pre-Development C = 0.30

Post-Development

5 - Yr Post-Development C (Controlled)= 0.61

5 - Yr Post-Development C (Uncontrolled)= 0.30



Time of Concentration, (Post) Tc = 10 minutes

5 YEAR STORM I = 70.25 mm/hr

CALCULATED OUTFLOW RESTRICTION = 0.0139 m3/s

100 YEAR STORM I = 119.95 mm/hr

CALCULATED OUTFLOW RESTRICTION = 0.0237 m3/s

5 YEAR STORM RUNOFF EVENT ALLOWABLE CONTROLLED AREA RELEASE RATE CALCULATION

PRE-DEVELOPMENT ALLOWABLE

RAINFALL RAINFALL PEAK CONTROLLED UNCONTROLLED CONTROLLED AREA

DURATION INTENSITY RUNOFF PEAK RUNOFF PEAK RUNOFF RELEASE RATE

(min.) (mm/hr) (m3/s) (m

3/s) (m

3/s) m

3/s

5 141.2 0.028 0.052 0.0022 0.0117

10 104.2 0.021 0.039 0.0016 0.0123

15 83.6 0.017 0.031 0.0013 0.0126

20 70.3 0.014 0.026 0.0011 0.0128

25 60.9 0.012 0.023 0.0009 0.0129

30 53.9 0.011 0.020 0.0008 0.0130

60 32.9 0.007 0.012 0.0005 0.0134

90 24.3 0.005 0.009 0.0004 0.0135

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 0.0123 m3/s

100 YEAR STORM RUNOFF EVENT ALLOWABLE CONTROLLED AREA RELEASE RATE CALCULATION

PRE-DEVELOPMENT ALLOWABLE

RAINFALL RAINFALL PEAK CONTROLLED UNCONTROLLED CONTROLLED AREA

DURATION INTENSITY RUNOFF PEAK RUNOFF PEAK RUNOFF RELEASE RATE


3/s) (m

3/s) m

3/s

5 242.7 0.048 0.109 0.0047 0.0190

10 178.6 0.035 0.080 0.0034 0.0202

15 142.9 0.028 0.064 0.0028 0.0209

20 120.0 0.024 0.054 0.0023 0.0214

25 103.9 0.021 0.047 0.0020 0.0217

30 91.9 0.018 0.041 0.0018 0.0219

60 55.9 0.011 0.025 0.0011 0.0226

90 41.1 0.008 0.018 0.0008 0.0229

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 0.0202 m3/s

APPENDIX A: STORMWATER MANAGEMENT MODEL

RATIONAL METHOD CALCULATION SHEET - ALLOWABLE CONTROLLED AREA RELEASE RATE

POST-DEVELOPMENT

December 10, 2013

POST-DEVELOPMENT




APPENDIX B

STORAGE VOLUME AND DISCHARGE RATES

Kollaard Associates Inc.


Job No.: 130038 top of sand 115.3

Location: 128 Reis Road, Carp, City of Ottawa, Ontario orifice diameter 0.1 top of weir 115.4

centre of orifice 1 115 weir coefficient 1.57

area of orifice 0.0079 Length of weir 3

coefficient 0.67 top of slope 115.7

Date: Note: - Pond details as shown on drawing 130038-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 m2

m2

m3

m3

m m m3/s m m

3/s m m

3/s m

3/s L/s

1 114.900 0.000 8.0 0.0 0.0 0.0 0.000 0.00 0.00 0.00 0.0000 0.0000 0.0

2 114.950 0.050 11.6 8.0 0.5 0.5 0.050 0.00 0.0000 0.00 0.0000 0.0000 0.0

3 115.000 0.050 21.1 11.6 0.8 1.3 0.100 0.00 0.0000 0.00 0.0000 0.0000 0.0

4 115.050 0.050 34.6 21.1 1.4 2.7 0.150 0.05 0.0000 0.00 0.0000 0.0000 0.0

5 115.100 0.050 50.0 34.6 2.1 4.8 0.200 0.10 0.0000 0.00 0.0000 0.0000 0.0

6 115.150 0.050 71.1 50.0 3.0 7.8 0.250 0.15 0.0000 0.00 0.0000 0.0000 0.0

7 115.200 0.050 98.4 71.1 4.2 12.0 0.300 0.20 0.0104 0.00 0.0000 0.0104 10.4

8 115.250 0.050 136.7 98.4 5.9 17.9 0.350 0.25 0.0117 0.00 0.0000 0.0117 11.7

9 115.300 0.050 196.8 178.6 9.4 27.2 0.400 0.30 0.0128 0.00 0.0000 0.0128 12.8

10 115.350 0.050 279.8 196.8 11.9 39.1 0.450 0.35 0.0138 0.0250 0.0010250000 0.00 0.0000 0.0148 14.8

11 115.400 0.050 405.0 279.8 17.0 56.1 0.500 0.40 0.0147 0.0500 0.0021000000 0.00 0.0000 0.0168 16.8

12 115.450 0.050 0.550 0.45 0.0156 0.0750 0.0032250000 0.05 0.0527 0.0715 71.5

Column 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

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 equationQ = 1.57 x L x H1.5

Column 3 Surface area of storage at Elevation n Column 14 Column 9 + Column 11

APPENDIX B: STORMWATER MANAGEMENT MODEL

STORAGE VOLUME AND DISCHARGE RATE

December 10, 2013

d

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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 / m3

Column 5 Storage volume between Elevation n and Elevation n-1

Column 6 Storage volume between Elevation n and bottom Note: Flow rate through sand using k = 45min/cm = 0.000013 m/s

Column 7 Elevation n - Bottom Elevation is three orders of magnitude slower than the flow rate through the orifice

Column 8 Elevation n - Elevation of Centre of Orifice and is therefore not significant with regard to storage calculations.

Column 9 Flow calculated by orifice equation Q = C*A*sqrt(2*g*H)

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

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APPENDIX C

STORMWATER MANAGEMENT

DESIGN DISCHARGE RATE AND STORAGE VOLUME REQUIREMENTS


Job No.: 130038

Location: 128 Reis Road, Carp, City of Ottawa, Ontario

Date: 28-Nov-13

Design Criteria:

Total Area contributing runoff from site 0.237 hectares Stormwater Quality Treatment Method

Total Controlled Area 0.218 hectares Sand Filter

Total Uncontrolled Area from Site 0.019 hectares Quality Storage Requirement =

Impervious ratio 0.774 37.0 m3/ha = 8.1

See Storm Water Design Report 130038

Pre-Development

Pre-Development C = 0.30 Maximum Allowable Release Rate 5 year Storm Event

Post-Development 0.0123 (m3/s)

5 - Yr Post-Development C (Controlled)= 0.61 Maximum Allowable Release Rate 100 year Storm Event

5 - Yr Post-Development C (Uncontrolled)= 0.30 0.0202 (m3/s)



5 YEAR STORM RUNOFF EVENT CALCULATION OF MAXIMUM STORAGE AND ACTUAL FLOW RATE FROM SITE

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


3) (m

3/s) (m

3/s) m

3/s (m

3) (m

3/s)

5 141.2 0.028 8.4 0.002 0.052 0.010 12.7 0.012

10 104.2 0.021 12.3 0.002 0.039 0.011 16.6 0.013

15 83.6 0.017 14.9 0.001 0.031 0.011 18.0 0.012

20 70.3 0.014 16.6 0.001 0.026 0.011 18.0 0.012

25 60.9 0.012 18.0 0.001 0.023 0.011 17.4 0.012

30 53.9 0.011 19.2 0.001 0.020 0.011 16.2 0.012

60 32.9 0.007 23.4 0.001 0.012 0.009 11.6 0.010

90 24.3 0.005 25.9 0.000 0.009 0.008 8.1 0.008

Max 18.0

APPENDIX C: STORMWATER MANAGEMENT MODEL

RATIONAL METHOD CALCULATION SHEET - REQUIRED STORAGE AND RELEASE RATE

PRE-DEVELOPMENT POST-DEVELOPMENT

Max 18.0

100 YEAR STORM RUNOFF EVENT CALCULATION OF MAXIMUM STORAGE AND ACTUAL FLOW RATE FROM SITE

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


3) (m

3/s) (m

3/s) m

3/s (m

3) (m

3/s)

5 242.7 0.048 14.4 0.005 0.109 0.013 28.8 0.018

10 178.6 0.035 21.2 0.003 0.080 0.015 39.1 0.018

15 142.9 0.028 25.4 0.003 0.064 0.015 44.2 0.018

20 120.0 0.024 28.4 0.002 0.054 0.015 46.6 0.017

25 103.9 0.021 30.8 0.002 0.047 0.015 47.4 0.017

30 91.9 0.018 32.7 0.002 0.041 0.015 47.2 0.017

60 55.9 0.011 39.7 0.001 0.025 0.015 37.0 0.016

90 41.1 0.008 43.8 0.001 0.018 0.013 29.5 0.014

Max 47.4

Column 1 2 3 4 5 6 7 8 9

PRE-DEVELOPMENT POST-DEVELOPMENT

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 5 + Column 8

For 5-year storms

For 100-year storms

(Column 6 - Column 7) x Column 1 x 60 s/min

( ) 814.0

05.6

071.998

+=

ct

i

( ) 82.0

014.6

071.1735

+=

ct

i




APPENDIX D

GRASSED SWALE DESIGN

Peak intensity of precipitation associated with a design storm

modelled as a Chicago Hyetograph

Method

i eqn 1

where i = average intensity of storm over duration under consideration (mm/hr)

t= time (minutes)

a,b,c =

Before the peak:

ib

After the peak:

ia

The Chicago Hyetograph is a model of storm intensity vs time derived from Intensity-Frequency-Duration

(IDF) curves of the format:

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:

(As published in Modern Sewage Design,

4th Edition , American Iron and Steel

Institute, 1999)

=a

[t + c]b

=a[{1 - b}{ta / (1 - r)} + c]

[ta / {1 - r} + c]1 + b

=a[{1 - b}{tb / r} + c]

[tb / r + c]1 + b

where 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

=a[{1 - b}{ta / (1 - r)} + c]

[ta / {1 - r} + c]1 + b

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)

25 mm

Consider a design storm of two year return period.

The City of Ottawa IDF curve constants are:

a = 732.951

b = 0.81 (City of Ottawa Sewer Design Guidelines)

c = 6.199

Substituting these constants into the IDF eqn

with t= 240 min

yields i = 8.47487012 mm/hr

The total precipitation over the duration of the storm is:

P = (i) x (duration)

= 33.90 mm

Minimum precipitation (over duration

of storm)

=a

[t + c]b

= 33.90 mm

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.

Peak Intensity according to Chicago Hyteograph

In Ontario, the ratio of time to peak over storm duration has been reported as:

r= 0.488 (Otthymo Manual)

tp = (r) x (duration)

= 1.95 hr

= 117.12 min

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:

112.24 to 122.24 minutes from start of storm

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:

Therefore, the instantaneous peak intensity for the storm under consideration would occur after an

elapsed time of:

The intensity during the peak time step is calculated by eqn 2 of this appendix as:

ib = 38.40 mm/hr

or by eqn 3 as:

ia = 38.40 mm/hr

ipeak = 38.40 mm/hr

over a time step of: 10 min

The peak intensity of precipitation of a 4 hr Chicago storm producing at least 25 mm of precipitation is:

=a[{1 - b}{tb / r} + c]

[tb / r + c]1 + b

=a[{1 - b}{ta / (1 - r)} + c]

[ta / {1 - r} + c]1 + b

Infiltration versus time based on the Horton Infiltration Equation

The Horton equation models the decay of infiltration over time as follows:

F = fc+(F0-fc)e-kt

where F = infiltration at time 't', mm/hr

fc = final infiltration rate, mm/hr

F0 = 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 )

F0 = 76.2 mm/hr (as per City of Ottawa Sewer Design Guidelines )

k= 0.00115 s-1

(as per City of Ottawa Sewer Design Guidelines )

t = 117.12 min (time to peak of Chicago Hyetograph)

The infiltration at the peak of the storm intensity is therefore calculated as:

t= 7027.2 s

e= 2.718

kt= 8.08128

e -kt

= 0.00031

F= 13.22 mm/hr

Net runoff based on calculated rainfall intensity and infiltration rate

Peak runoff rate from vegetated surfaces = Intensity-Infiltration rate

Peak runoff rate from impermeable surfaces = Intensity of precipitation

Intensity of precipitation 38.40 mm/hr (Peak of 4 hr Chicago storm)

Infiltration rate 13.2195 mm/hr

Peak unit runoff rate from vegetated areas 25.18 mm/hr (precipitation - infiltration)

Catchment Area 0.22 ha

Impervious ratio 0.77

Peak runoff rate from vegetated areas 0.003539 m3/s (unit runoff x vegetated area)

Peak runoff rate from impervious surfaces 0.018069 m3/s (precip x impervious area)

Peak runoff rate 0.0216 m3/s

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:

( Horton eqn for t = peak

intensity)

Velocity and depth of flow in a grassed swale for a given flow rate

Peak Flow rate1

m3/s Q= 0.022 m

3/s

Swale dimensions

Bottom width m b = 0

Side slopes horiz/vert m/m m = 3

Bottom slope m/m S = 0.0035

Manning roughness n = 0.027

Cross section area m2

Ax= 0.060492

Wetted perimeter m P = 0.89808686

Hydraulic radius m R = 0.06735651

Depth of flow m y = 0.142

Velocity m/s V= 0.357

Manning flow rate2

m3/s Q = 0.022

(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

= (b + my)y

= b + 2y(1 + m2)

0.5

= Ax / P

= Q / Ax

= 1 / nAxR2 / 3

S1 / 2

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.

Percolation and Drawdown of Water Quality Storage

Method

Qperc (MOE Manual eq'n 4.20)

where: Qperc = Percolation rate, m3/s

LW = approximate wetted area of storage, m2

f= Longevity factor

n= Porosity

P= Unit percolation, mm/hr

t= V/Qperc

where: V= Water quality storage volume, m3

Calculations

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.

The percolation rate was used to estimate the time that would be required for the water quality storage to

infiltrate:

The rate of percolation of stored water is calculated according to the method suggested in the MOE Manual

for grassed swales, as follows:

= fP

3600000LWn

Calculations

V = 8.1 (water quality storage)

LW = 95 (wetted area approximated from drawing)

P = 13.2

f = 1 (MOE Manual, value for grass swale)

n = 1 (MOE Manual, value for grass swale)

Qperc = 0.000348

t= 23254 seconds

t= 6.5 hrs

(City of Ottawa sewer design manual, default

value for final infiltration rate, this is a

conservative estimate for this soil)

= fP

3600000LWn

Summary of Grassed Swale Design for Water Quality Treatment

Design Storm for treatment in grassed swale 2 yr, 4 hr 25 mm 4hr

Total Precipitation of Design Storm (mm) 33.90 > 25 min

Peak flow rate in swale for Chicago Storm (m3/s) 0.021609 < 0.15 max

Maximum velocity (m/s) 0.357215 < 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

MOE Criteria

Provided

in Design

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APPENDIX E

RESPONSE TO MVCA COMMENTS


Structural • Environmental •

Materials Testing •




Ontario Authorized by the Association of Professional Engineers

of Ontario to offer professional engineering services.

2013.12.10 Justyna Garbos City of Ottawa Planning & Growth Management Development Review Rural Services 110 Laurier Avenue West, 4th Floor Ottawa, ON, K1P 1J1 E: [email protected] Re: Site Plan Control application D07-12-13-0147 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 =

0.002 m/s to model flow through the filter sand (k value corresponding to the specified sand with T

…130038 Page 2

Civil • Geotechnical • Structural • Environmental • Industrial Health & Safety

= 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.

imalcolm

imalcolm

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2013.12.10




APPENDIX F

RESPONSE TO CITY OF OTTAWA COMMENTS


Structural • Environmental •

Materials Testing •




Ontario Authorized by the Association of Professional Engineers

of Ontario to offer professional engineering services.

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: [email protected] T: 613-580-2424 ext. 29233 F: 613-580-2576

Re: Site Plan Control application D07-12-13-0147

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.

Kollaard File # 130038 Page 1

Response to Site Plan Control Application

City of Ottawa File D07-12-13-0147

Circulation Comments

…130038 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 115.50. 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.

Response to Site Plan Control Application

City of Ottawa File D07-12-13-0147

Circulation Comments

…130038 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

imalcolm

imalcolm

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2013.12.10

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