Toc & Appendice

Table of Content 1.

Introduction…………………………………………………………… ……………………… 1

1.1

Background ………………………………………………………………………… ……. 1

1.2

Purpose and Scope ……………………………………………………………………. 2 Site Description ……………

2.

……………………………………………………………….. 3 Existing Land Use and Vegetation .

2.1

…………………………………….………. 4 Existing Soil and Groundwater Condition .

2.2

………………………………….. 5 2.3

Topography and Surface Water Drainage …………………………………… 6

2.3.1

Preliminary Drainage Area ……………………………………………………. 6

3.

Stormwater Management Design Overview ……….. …………………………. 10

3.1

Problem Definition ………………………….. ……………………………………… 10

3.2

Considerations …………… …………………………………………………………… 11

1

Main Channel Design

4.

…………………………………………………………………… 13 4.1

Main Drainage Area A ………………………………………………………….…… 13

4.2

Main Channel Design …………………………………………………………….…. 15

4.3

A Runoff Routing Drainage Area A ………………………………………….…. 17

4.4

Channel Design using Manning’s Equation ………………………………… 18

4.5

Main Drainage Swale Conclusion …………………………………………….. 23 End of Pipe Extended Detention Facilities

5.

……………………..……………… 24 5.1

Water Quantity Control ……………………………………………………………. 25

5.1.1

Runoff Computation ………………………………………………………….… 25

5.1.2

Drainage Area …………………………………………………………………… … 25

5.1.3

Runoff Coefficient ………………………………………………………………. 26

5.1.4

Rainfall Intensity and Time of Concentration ……………………….. 28

2

5.1.5

Design Details of Proposed Pond …………………………………………. 31

5.1.6

Flow Diversion Structure …………………………………………………….. 34

5.1.7

Outlet Design …………………………………………………………………… … 35 Water Quality Control .

5.2

……………………………………………………………. 36 5.2.1

Design Criteria ……………………………………………………………………. 36

5.3

Other Considerations …….. ………………………………………………………. 39 Secondary Drainage Channels …..

6.

…………………………………………………. 40 6.1

Existing Profiles of Secondary Channels …………………. ………………… 42

6.1.1

Minor Drainage Swale MinDS ……………………. ……………………….. 42

6.1.2

Major Drainage Swale MajDS ……………………. ……………………….. 43

6.1.3

Minor Drainage Culvert MajDS ……………………. ……………………... 44

6.1.4

Major and Minor Drainage Swale MMDS …………………………….. 45 3

6.2

Secondary Drainage Channels Design Constraints …………………….. 46

6.3

Design using Manning’s Equation …………………………………………….. 48

6.4

Secondary Drainage Conclusion ……………………………………………….. 53

7.

Conclusions and Recommendations …………………………………………….. 54

References

4

LIST OF TALBES Table 2.1

Runoff Coefficient for Use in the Rational Method

Table 5.1 Drainage Areas, Land Covers and Runoff Coefficients for Postdevelopment Table 5.2

Summary of Quantity Volume and Peak Flows

LIST OF FIGURES Figure 2.1 Plaza Site Outlined Figure 2.2 Outlined drainage area based on rough contour outline Figure 2.3 Existing flow path of water Figure 2.4 Divided Drainage Areas Figure 4.1 Channel and pond configuration Figure 4.2 Existing main channel elevation profile Figure 4a

A Post Development Drainage Pattern For Drainage Area A

Figure 4.3 Swale Figure 4.4

Post Development Swale Elevations

Figure 4.5 Main Drainage Swale Cross sectional Dimensions in Meters Figure 5.1 Layout of the Canadian Plaza Figure 5.2 Velocities for upland method of estimating tc Figure 5.3 Intensity Duration-Frequency Curve (IDF Curves) - City of Windsor Figure 5.4 Layout of the ponds and channels Figure 5.5 Cross-Section of Overflow Swale – to Quantity Pond

5

Figure 5.6a Cross-Section of Flow Diversion Structure Figure 5.6b

Plan view of Flow Diversion Structure

Figure 5.7 Outlet Design Figure 5.8 Cross-Section of Overflow Swale- to Quality Pond Figure 6.1 Secondary Drainage Channels Layout Figure 6.2 Secondary Drainage Channel Outline Figure 6.3 Pre existing elevation profile of Line P6-P5-P4-P3-P2, MinDS Figure 6.4

Pre existing elevation profile of Line P6-P7-P8-P9-P10-P11, MajDS

Figure 6.5 Pre existing elevation profile of Line P2-P7, MajDC Figure 6.6 Pre existing elevation profile of Line P1-P2, MMDS Figure 6.7 Elevation Profile For P11-P10-P9-P8-P7-P2-P1. Figure 6.8

MinDS cross section

Figure 6.9 Post Development MinDS Elevation Profile Figure 6.10

MajDS cross section

Figure 6.11

Post Development MajDS Elevation Profile

Figure 6.12 MajDC cross section Figure 6.13 Post Development MajDC Elevation Profile Figure 6.14 MMDS cross section Figure 6.15

Post Development MMDS Elevation Profile

LIST OF APPENDICE Appendix 1 Water Level Calculations for Channels using Manning’s Equation Appendix 2 Rational Method SWM Calculations Appendix 3 Preliminary Report

6

References Archaeological Service Inc., 2008, Draft Practical Alternatives Evaluation Working Paper - Archaeology, April 2008, Available Online: http://www.partnershipborderstudy.com/pdf/Archaeology/WEB_Practical AltsWP_Archaeology_April2008-reporttextonly.pdf Atlas of Canada, 2008, Toporama – Topographic Map, Retrieved on March 16, 2009, http://atlas.nrcan.gc.ca/site/english/maps/topo/map Atmospheric Environment Service of Canada, 2008, IDF Curves of City of Windsor, Retrieved on March 5, 2009 City of Windsor, 2008, Sewer Atlas, Retrieved on March 16, 2009, http://www.citywindsor.ca/documents/GIS/SewerAtlas/AtlasSewersIndexPage.pdf DRIC, 2008, Map - Technically and Environmentally Preferred Alternative U.S.

Plaza - Crossing X10(B) - Canadian Plaza B1 - Windsor Essex Parkway, Retrieved on March 18, 2009, http://www.partnershipborderstudy.com/pdf/DRIC_PlazaCrossPlaza_TEPA-Web.pdf

Environment Canada,1987, Remedial Action Plan – Detroit River, 1987, Available Online: http://www.ec.gc.ca/raps-pas/default.asp? lang=En&n=3B1C62BD-1 Golder Associates Ltd., 2008, Pavement Engineering for Planning Report Area of Continued Analysis-Detroit River International Crossing (Updated Draft), March 14, 2008, Available Online: http://www.partnershipborderstudy.com/pdf/Pavement/WEB_PracticalAlt sWP_Pavement_March2008-report&apps.pdf J.F. Sabourin and Associates Inc., 1997, Evaluation of Roadside Ditches and Other Related Stormwater Management Practices – Final Report, April 1997

Kooijman, B., 2005, Mass balance, October 1, 2005, Retrieved on November 21, 2008, http://en.wikipedia.org/wiki/Talk:Mass_balance LGL Ltd., 2008, Draft Practical Alternatives Evaluation Working Paper – Natural Heritage, April 2008, Available Online: 7

http://www.partnershipborderstudy.com/pdf/Natural/WEB_PracticalAltsW P_Natural_April2008-report&apps.pdf Mays, Larry, 2005, Water Resources Engineering, John Wiley & Sons Inc., Printed in United States Ministry of Environment, 2003, Stormwater Management Planning and Design Guidelines, 2003, Available Online: http://www.ene.gov.on.ca/envision/gp/4329eindex.htm Mississippi State University, 2004, OIL/GRIT SEPARATOR, November 5, 2004, Retrieved on November 21, 2008, http://www.abe.msstate.edu/csd/NRCSBMPs/pdf/water/quality/oilgritseparator.pdf Reid, D. W, 2003, South Windsor CT, February 5, 2003, Retrieved on November 22, 2008, http://www.southwindsor.org/pages/SWindsorCT_Wetlands/2003/S00153 F7F?textPage=1 Study, D. R., 2008, Detroit River Internationnal Crossing Study, November 12, 2008 Retrieved on November 22, 2008, http://www.partnershipborderstudy.com/reports_canada.asp URS Canada Inc., 2008, Draft Environmental Assessment Report, November 2008, Available Online: http://www.partnershipborderstudy.com/pdf/1112-08/DraftEA_combined_withapps.pdf

8

APPENDIX 1 Water Level Calculations

9

Section 4 Water level calculation for 100year storm of MainDS using Manning’s equation: Q n Bw Z So

9.330 5 0.03 7 2.5 0.001 25

10

Water level calculation for 5year storm of MainDS using Manning’s equation: Q N Bw Z So

4.4675 0 7 2 0

Section 5 Water level calculation for 5 year storm of Overflow Swale to Quality Pond using Manning’s equation: Q n Bw Z So

4.467 5 0.03 5 2 0.002 5

water level for 5 year = 0.656m depth 11

Water level calculation for 100 year storm of Overflow Swale to Quantity Pond using Manning’s equation: Q n Bw Z So

4.863 0.03 7 2.5 0.005

*note: Q = Qpost100 - Qpost5

water level for 100 year = 0.4675m depth

12

Section 6 Water level calculation for 100year storm of MMDS using Manning’s equation: Q n Bw Z So

7.6628 0.03 8.5 2.5 0.0012 5

13

Water level calculation for 100year storm of MMDS using Manning’s equation: Q n Bw Z So

2.310 7 0.03 6 2.5 0.001 25

Water level calculation for 100year storm of MajDS using Manning’s equation: Q n Bw Z

5.352 1 0.03 6 2.5 14

So

0.001 25

Water level calculation for 100year storm of MajDC using Manning’s equation: Q n Bw Z So

5.352 1 0.017 6 2.5 0.001 25

15

APPENDIX 2 Rational Method SWM Calculations

16

Storage Detention Calculations External Area Approximate Plaze Area Total Drainage Area Length (m) General Fall (m)

m2 95956 543000 638956 1776 6

Runoff Coefficient (C) Concrete/Roof Asphalt Landscape Area

5 year 0.8 0.77 0.34

100 year 0.97 0.95 0.47

Tc = L / 3600*V L = ft

V = ft/s

Tc = hr

L = 1776 m = 1776 × 3.28 = 5825.28 ft 35.3 mins

Tc = 0.588 hr =

V = 2.75 ft/s (for paved area)

From IDF curve

Return period 5 years 100 years

Intensi ty (mm/h r) 46 75

Q = C × i × A / 360 i = mm/hr A = ha Pre-Development Peak Flows 17

Return Period

Area

Coefficient (C)

5 yrs

63.8956

0.34

100 yrs

63.8956

0.47

Peak Flows (m3/s) 2.775 9 6.256 4

Post-Development Peak Flows Return Period 5 yrs

Landscape Paved area Concrete total

100 yrs

Area 33.224 4 29.008 3 1.6629 63.895 6

Coefficient (C)

33.224 4 29.008 3 1.6629 63.895 6

Landscape Paved area Concrete

Qpost > Qpre

Peak Flows (m3/s)

0.34 0.77 0.8 0.5472

4.4675

0.47 0.95 0.97 0.7009

9.3305

Storage Detention Require

Srequired = 0.5(Qpost × Tbase) – 0.5 (Qpre × Tbase) Flow Postdevelopment Peak Flow, Qpost

Storage Required, S

Predevelopment Peak Flow, Qpre 18

Tbase = 2tc or 2.67 tc

Time

Tbase = 2.67 × 35.3 = 94.3 mins = 94.3 × 60 = 5655.82 s Sreq5 = 4783.6521 m3



5 yr post released at 5 yr pre

Sreq100 = 8693.129m3



100 yr post released at 100 yr

pre

Therefore, the maximum storage required is 8693.129m3.

Quality Control Storage Calculations

Enhanced Protection - 80% Suspended Solids Removal For 85% impervious  250 m3/ha storage

includes 40 m3/ha for active

19

Active Storage = 40 × 63.8956 = 2555.824 m3 Permanent Pool = (250 – 40) × 63.8956 = 13418.08 m3 Total Storage = 2555.82 + 13418.08 = 15973.9 m3

Area of the quality pond = 9127.943 m2

for 1.75m depth

Permanent Depth = 1.47m Active Depth = 0.28m

20

Outlet Pipe for Quality Pond

The detention time for the quality pond must be equal or greater than 24 hours.

VactiveQp @12maxdepth ≥ 24 hours

Qpre = 10.013 × π2 y2 × (12y)2/3 × S1/2 Vactive = 2555.824 m3 248.5mm Qpre = 2.7759 m3/s

24 hrs = 86400 s S = 1% = 0.01

y = 0.124 m  d = use 250mm

Therefore, the drainage pipe from quality to quantity is 250 mm diameter

21

APPENDIX 3 Preliminary Report

22

1

Methodology In order to properly assess the potential use of various alternative drainage systems, the following aspects should be considered: 1)

Compatibility with physical site characteristics;

2)

Compatibility with planning objectives and ease of integration within the road right of way;

3)

Ability to meet stormwater management objectives;

4)

Economics; and

5)

Public acceptance / safety.

6)

Site elevation

There are two approaches used for stormwater management in this project: i)

Urban Drainage System Selection Tool (UDSST)

ii) Mass Balance Approach

1.1

Urban Drainage System Selection Tool

(UDSST) This tool is developed by J.F. Sabourin and Associates Inc. It is a Microsoft Excel Spreadsheet application for development of different solutions relating to stormwater management. The tool helps to determine which types of alternative drainage features could be used 23

within a site and to compare potential conceptual drainage systems. It is also used to calculate the quantities of materials needed to build a proposed drainage system based on drainage area and imperviousness. This is achieved through the use of the 6 detailed tables: •

Table A – Site Characteristics

•

Table B – Development Characteristics

•

Table C – Identification of Compatible Features

•

Table CD – Stormwater Management Objectives

•

Table D – Comparison of SWM Function Potentials

•

Table E – Comparison of Conceptual Drainage Systems

The step by step procedure can be visualized by a flowchart (see Figure 3-1). Table A – Site Characteristic It is used to eliminate specific drainage features which are incompatible with the local site characteristics Table B – Development Characteristics It is used to eliminate options which are incompatible with exisiting or potential development characteristics. Table C – Identification of Compatible Features

24

It is used to summarize the results obtained from Tables A and B, and to identify which drainage features could be incorporate in a conceptual system Table CD – Stormwater Management Objectives It is used to summarize the stormwater management objectives and target performance for the drainage system being considered. It is also used to assign variable priorities to the various SWM objectives which are to be met. Table D – Comparison of SWM Functions It was prepared as a reference and provides an indication of how well a particular drainage feature can respond to a particular SWM objective. SWM objectives were divided into 5 groups: i)

Groundwater recharge

ii) Erosion control iii) Quality control iv) Flood control v) Thermal reduction The water quality control objective was further divided into 4 subgroups: i)

Sediment removal

ii) Nutrient removal 25

iii) Bacterial die-off iv) Oil and grease removal. Table E – Comparison of Conceptual Drainage Systems It is used to describe and evaluate possible conceptual drainage systems. The evaluation is based on potential SWM performance, specific design objectives and costs.

1.2 Mass Balance Approach A material balance approach will be used to address the drainage problem of the storm water management system. This approach can be defined as an application of the law of conservation of mass. (Kooijman, 2005) By accounting for material entering and leaving a system, mass flows can be identified which might have been unknown, or difficult to measure. (Kooijman, 2005) In this case, the mass conservation inputs will be considering the maximum rainfall expected during a 100 year storm. A 100 year storm is 75mm/h of rain for 35 minutes. The output of the system will consider pond discharge into the Detroit River. Manning’s Equation: The Manning’s equation will be applied to determine the Dimension, Slope and Water level of various channels projected to be designed in the technical report. The Manning’s equation is expressed as follows. 26

Q=1n*AR23S0.5

Where Q is the Channels flow n is the roughness coefficient, A is the cross sectional area of the channel, R is the Hydraulic radius and S is the slope.

Rational Method: Rational Method will be employed to determine the pre development flow and post development flow of runoff landing on the site. The design of the major storm water management structures including the Pond and the Drainage Channels will be based on the Rational Equation’s Outputs. The rational equation is expressed as follows. Q=CiA Where Q is the expected storm flow, C is the runoff coefficient, i is the rainfall intensity and A is the Drainage area. This Equation will be discussed more in detail in the technical report.

Storm-water Management Structure placement:

27

To address the water quality problem installation of an oil/grit separator at each entry point of the pond. The oil/grit separator will have a size to accommodate the maximum in-flow rate of its respective drainage pipe. In addition to that, stones will be placed at the bottom of all the drainage channels to carry out some preliminary grit removal work. We will also place water flow control structures which will regulate the inflow and outflow of the pond and other sites around the project. To address the sediment control problem, we will place large rocks and shrubbery in strategic locations such that it protects the site from erosion and makes the site appears environmentally aesthetic.

2

Stormwater Management Plan The Canadian Plaza is approximately 53 ha, consisting primary of pavement and commercial buildings. The proposed Highway 401 enters from the east, with the roadway to the new bridge extending to the north. The stormwater management for the Plaza will require quality, quantity and erosion controls for the peak flows from the Plaza, as increase in impervious area will increase the overall peak flows from the site, as well as the overall pollutant loading. This would lead to erosion issues downstream of the site, as well as impacts to the ecological condition of the Detroit River.

28

2.1 System Selection Tool Approach Alternative 1 Alternative 1 consists of wet ponds, oil and grit separators, greenbelts and backyard swales and shallow storm sewers with sump pumps. The storm sewers with sump pumps can be designed to provide possibly off-site flood control if the major system is retained on the street and catch basins are equipped with inlet control devices. If the sump pumps discharge to a grass surface area, some groundwater recharge may be achieved. The storm sewers can also provide some thermal impact reduction. The oil and grit separators (O&Gs) are devices which cannot be used by them to create a drainage system. Usually their use is combined with the use of conventional storm sewers. O&Gs are large manhole structures consisting of separate chambers (usually 3) through which stormwater travels in order to remove coarse sediments, oils and other floatable pollutants. O&Gs can provide some quality control. The only real site constraint in using O&Gs is with the depth of the drainage outlet which has to be sufficiently deep to accommodate the device’s physical requirements. Wet pond is a type of end-of-pipe SWM facilities which can be considered for drainage areas of at least 5.0 ha. When properly constructed they can provide adequate erosion and water quality control benefits, and possibly some offsite flood control. Based on the UDSST, the system compliance of 29

alternative 1 is 81% and the overall score as per SWM priorities is 16.91. The total estimated cost of this system is $2,620,847.90. (See Table 5-1)

Alternative 2 Instead of wet pond in alternative 1, alternative 2 use dry pond. The system compliance of this alternative is 78% and the overall score as per SWM priorities is 16.36. The total estimated cost of this system is $2,557,484.58. (See Table 5-2) The preferred stormwater management plan, based on the cost analysis and system compliance, would be associated with Alternative 1. Since there is expected quality of inflowing stormwater on site, so the use of dry ponds is prevented. Although the cost of alternative 2 is lower than alternative 1, but the cost over the overall score of the systems is $156, 360.63, higher than $154, 969.72 in alternative 1. (See Table 5-3)

2.2 Mass Balance Approach Pond Size: The first challenge is determining the amount of water the site will experience during a 100 year storm. From Windsor statistics the

30

storm thickness of a 100 year storm is 75mm/h for 35minutes. The site area will roughly cover a 53 ha.total Rainfall volume is 231875m3 since pond cannot be lower than 2 m. Total pond area is 115938m2. Drainage: One of the most important aspects of this project will be the design of the drainage channels to divert the storm water efficiently into the site pond. The first part of this methodology will be to use gravity to our advantage and design the flow system to coincide with the way water would naturally flow. From the following conceptual diagram of the site there are 4 major sides covering the site. The East and North side of the border crossing are the Entry-Exit point of Windsor and Detroit respectively. The West side of the crossing is the Detroit River. The south side is bordered by a large rock drainage swale. From discussion with the project engineer, the North and East slopes will point towards the plaza after final grading, this means that when it rains, the water from surrounding area will flow towards the plaza. It is imperative that catch basins and drainage channels are placed properly on the site such that water is diverted as efficiently as possible into the pond. The following drawing is a conceptual view of the project sloping and drainage system.

31

From drawing we see the pond is taking-in water from the East and North sides of the site by means of channeling and gravity. The pond will be taking in all the water mostly from the large rock swale and the smaller diversion channels spread across the site area. Channel design: The next challenge is to determine the type of drainage inlets based on site location. Since the Asphalt area is quite large. Standard catch basins will be too small to handle the inflow of a 100 year storm. Placing curb on this site will also work inefficiently to divert the rainwater because given a 22cm rainfall thickness of a 100year storm (assuming no absorption) the curb would have to be a minimum of 22cm to hold the rainfall, it would make the roads dangerous to drive on because vehicles could be submerged in water. There are two conceptual designs of drainage channels which will appropriately mitigate the drainage problems mentioned above, one will be the channel design of asphalted surfaces the other will be the channel design of non-asphalted surfaces. For asphalted surfaces we propose the following conceptual design is it intended to be placed under the asphalt driving surfaces. It will be designed with the structural capacity to hold the largest of vehicles and it will also be very efficient in diverting the rainwater off the roads. In addition to

32

that, the rock at the bottom of the channel will be used to treat the grit before water enters the Oil/Grit chambers.

The next diagram will show the cross section of a storm water channel of non-asphalted surfaces it works similarly to the one above except it is exposed to open air and has a bottom rubber liner to protect the channel from water erosion.

Oil/Grit Chambers: Before storm water is introduced into the pond oil grit separators will be placed, which will carry out the bulk of the grit and oil removal work. An oil and grit separator will help the pond be environmentally friendly and in prove the quality of water that will eventually be discharged into the Detroit River. The Oil/ Grit separators will be design to handle the maximum flow arising from a 5 year storm. The following diagram will illustrate how the oil grit separator works.

33

(Mississippi U, 2004) The next diagram is a conceptual outline of water diversion process for the entire project.

Assessement of Alternatives Alternative 2 addresses the water quality and Sediment control aspect of the border crossing site satisfactorily. The oil grit chamber will success fully remove most oil contaminants during a 5 year storm, assuming that the Oil/Grit chamber is designed to sustain the flow of a 5 year storm. Ideally a small water treatment plant would be Ideal to remove all the contaminants; 34

however a treatment plant would be too expensive to build and operate so it is unfeasible. So in terms of treating storm water this is the most feasible alternative. In addition to that, when storm water is ponded, some of the toxins are captivated by the pond life. So less contaminant can reach the Detroit River. As mentioned above in the alternative development section of alternative 2, a lot of the grit removal is carried out by the rocks at the bottom of the drainage channels. In addition to that toxins will be captivated by the vegetation that will eventually grow on the channel’s rocks. These organisms will remove some toxins and BOD’s from the storm water.

Alternative 2 also mitigates the drainage because all drainage channels are highly permeable, erosion proof and large enough to handle a high capacity of water. By mitigating the drainage problems of the site, roads are safe to drive on during even a 100 year storm.

The negative aspect of alternative 2 is that there will be drainage channel scattered throughout the site which may make the site look un-aesthetic. However site aesthetics can be easily changed by planting tree and other greeneries along these channels to make them look more natural.

Alternative 1 is also a satisfactory alternative because it effectively addresses all problems mentioned in the introduction. The Urban Drainage 35

Selection Tools Program is intended to be used as a guide line for hydrological engineers working on storm water systems. The outputs of this program are storm water management solutions relevant for the given project. After inputting all the correct values into the program we found that Oil/Grit Chambers, Green Belts, Back yard swales, a wet pond and a sump pumps would address most storm water management problems. The water quality aspects of the project are addressed with the Oil/Grit separators. The drainage problems are addressed with the backyard swales, sump pumps, wet pond and large catch basins. The sediment control and aesthetic problems associated with this project are addressed by the green belt, backyard drainage swales and Grit chambers.

Conclusion and Recommendations Alternative 1 and alternative 2 are very similar. This is a favorable outcome because the two alternatives where developed independent of each other, it reinforces the sites requirements. The similarities of the Alternative 1 and 2 are that a pond, Oil/Grit chambers, Open swales and a green belt are site requirements. The difference being that alternative 2 recommends gravitational movement of water as opposed to alternative 1’s sump pump solution. In this case we will go with alternative 2 because no power will be required to move the storm water as opposed to alternative 2 which requires a sump pump. Alternative 2 suggests a permeable continuous grid to be the 36

entry point of water whereas alternative 1 suggests large manhole catch basins to be the entry point of storm water. Alternative 2 is a better alternative because the steel grid has a larger permeable surface area to take in the water. In conclusion alternative 2 works best to address the storm management problems of this project. In addition to that Alternative 2 is also slightly less expensive than alternative 1.

37