Skip to main content

Eastern Subwatersheds Stormwater Management Retrofit Study

Project Status: 
Underway

Online Information Session #2 - June 15 to July 13, 2018

Posted: 
Wednesday, June 13, 2018, 11:51 am
Last updated: 
Thursday, June 14, 2018, 9:05 am

Dates & Times

Friday, June 15, 2018, 8:00 am to Friday, July 13, 2018, 5:00 pm

Online Information Session 
ottawa.ca/eastsubwatersheds

The City of Ottawa has initiated the Eastern Subwatersheds Stormwater Management Retrofit Study to identify a strategy for Taylor Creek, Voyageur Creek, Bilberry Creek, and the urban tributaries of Green’s Creek. This Study is one of 17 Ottawa River Action Plan projects.

The study rationale, objectives and existing conditions were presented at the first Online Information Session in July 2014. This information remains available on the City’s website (ottawa.ca/eastsubwatersheds).

You are now invited to the last Online Information Session to review and comment on the draft final results of the study. The proposed retrofit plan provides a strategy to help mitigate the impacts of uncontrolled runoff from areas in the east end of the city that have little or no stormwater management. This Study has been carried out as a Master Plan in accordance with the requirements of Phases 1 and 2 of the Municipal Class Environmental Assessment.

Open House Display Boards [ PDF 1.510 MB ]

Please provide your comments by July 13, 2018. The study team will review all comments and respond to any concerns or questions before the study is finalized.

For more information, or if you wish to have your name added to the mailing list, please contact:

Laurent Jolliet, P. Eng.
Project Manager / Asset Management
City of Ottawa
Email: Laurent.jolliet@Ottawa.ca
613-580-2424, ext. 17149

Contact

Laurent Jolliet

Overview

The City of Ottawa has undertaken this study to develop a Stormwater Management Retrofit Plan for the Eastern Subwatersheds. Please review the video presentation and other information provided that describes:

  • What the Eastern Subwatersheds are
  • What stormwater is
  • What stormwater management retrofit is
  • Why this study is needed
  • The study area [ PDF 391.28 KB ] and existing conditions
  • How the study has proceeded
  • The Draft Preferred Stormwater Management Retrofit Plan

If you would like more detail about the study, please refer to the information provided at the link below:

Municipal Class Environmental Assessment

The Eastern Subwatersheds Stormwater Management Retrofit Study has been undertaken in accordance with the Municipal Class Environmental Assessment (MCEA), an approved process under Ontario's Environmental Assessment Act. The study has followed the MCEA's Master Planning Process satisfying the first two phases of this Class EA process. More detailed assessments will be required for individual projects that are recommended in the plan. The retrofit plan will become the basis for, and will be used in support of, these future assessments and evaluations. 

Objectives

Objectives* define a desired endpoint or condition, and the direction of change that is needed to arrive at that endpoint.

  1. Reduce flood risk to public health and safety and to property along the Creek** corridors
  2. Reduce erosion impacts in the Creek corridors that are detrimental to property, infrastructure and stream habitat
  3. Preserve and/or re-establish a more natural hydrologic cycle for the Eastern Subwatersheds
  4. Improve water quality in the Creeks and the Ottawa River by reducing the impact of runoff
  5. Reduce the impacts of runoff on the Petrie Island Beach
  6. Protect, enhance or rehabilitate natural features and functions along the Creek corridors
  7. Increase public awareness about stormwater management and public involvement

* Note: the numbering is for convenience and does not indicate priority
** The Creeks referenced include Bilberry, Voyageur, and Taylor Creeks and the urbanized tributaries of Green's Creek (MacEwan Creek, Cyrville Drain, and Mather Award Drain).

Notice of study commencement and online information session - 2014

July 31 to September 19, 2014

The City of Ottawa has initiated the Eastern Subwatersheds Stormwater Management Retrofit Study to identify a strategy for Taylor Creek, Voyageur Creek, Bilberry Creek, and the urban tributaries of Green's Creek. This Study is one of 17 Ottawa River Action Plan projects.

Study Area [ PDF 391.28 KB ]

When complete, the Study will provide a strategy to help:

  • Improve water quality in the Creeks and the local reach of the Ottawa River
  • Re-establish a more natural hydrologic cycle for the Eastern Subwatersheds
  • Reduce flooding and erosion in the Creeks
  • Improve stream health
  • Reduce the impacts of stormwater runoff on Petrie Island Beach

This Study has been carried out as a Master Plan in accordance with the requirements of Phases 1 and 2 of the Municipal Class Environmental Assessment.

Online information session #1 – July 31, 2014 to September 19, 2014

These videos provide an overview of why this study is being done, how it has proceeded, what the City hopes to achieve, and how the study results may affect you. After viewing the video, please proceed to the overview.

Part 1 - Introduction

Part 2 - Overview of the study area and stormwater management retrofits

Part 3 - Overview of existing conditions in the study area

Part 4 - Overview of the study process and schedule

The preliminary results of the study, including the draft Preferred Retrofit Plan [ PDF 2.8 MB ] were presented at City Hall on June 14, 2014 during the Water Round Table event.

Online Information Session Script

Slide 1: Eastern Subwatersheds Stormwater Management Retrofit Study

  • Welcome to the Online Information Session for the Eastern Subwatersheds Stormwater Management Retrofit Study.
  • Thank you for taking the time to watch this presentation. This video provides a quick overview of why the study is being done, how it has proceeded, what the City hopes to achieve, and how the study results may affect you. This is the first part of a 4-part presentation.

Slide 2: What is stormwater?

  • Let's begin with water and how it is recycled in nature. Water evaporates from lakes, rivers and oceans. It then becomes water vapour and forms clouds. It falls back to the earth as rain or snow, then it evaporates again.
  • This cycle never stops. Water falls as rain or snow, soaks into the ground, evaporates, gets taken up by plants, or runs off the surface to local streams and rivers. This is called the water balance.

Slide 3: What is stormwater?

  • Stormwater is the runoff that results from rain or melting snow. In urban areas, the increased runoff generated by changes in land use alters the natural water balance. When fields and forests are replaced with roads and buildings, less rainfall can infiltrate back into the ground, less gets taken up by plants and more runs off the surface.
  • In urban areas, this increased runoff quickly drains to local streams and rivers from paved surfaces and storm sewers.

Slide 4: What is stormwater management?

  • Some 30 years ago in Ontario, the impacts of urban development on receiving watercourses began to be widely recognized: degraded water quality; increased flooding; and higher rates of erosion, damaging property and infrastructure and destroying fish habitat.

Slide 5: What is stormwater management?

  • Stormwater management practices aim to avoid the impact of urban development on receiving watercourses by building in measures that mitigate these impacts. For example, constructed ponds allow solid pollutants to settle out before the runoff is discharged to the nearest stream or river.
  • Stormwater management has been applied to new urban development since the 1980s. Over the last few decades, it has evolved from a single focus on reducing flooding to include improving water quality and reducing the total amount of runoff by designing sites to allow more rainfall to soak back into the ground. All these efforts are aimed at trying to mimic the runoff patterns that existed before the land was urbanized.

Slide 6: What is stormwater management?

  • Most of the City of Ottawa was built before stormwater management became a standard requirement. In older areas of the city, stormwater runoff discharges directly to creeks and rivers with no treatment or control of any kind. The continued discharge of uncontrolled stormwater runoff to the Ottawa River and its many tributaries has been recognized as an important issue for the City to address. In response, the City launched the Ottawa River Action Plan, known as ORAP, in 2010. ORAP is the City's working plan to improve and protect the health of the Ottawa River and its many tributaries. You can learn more about ORAP by choosing the link provided on the introductory page of this study's website.

This is the end of Part 1. Please proceed to Part 2 for an overview of the study area and more information about stormwater management retrofits.

Slide 7: What are the Eastern Subwatersheds?

  • ORAP identified the Eastern Subwatersheds as a priority area to address the impacts of uncontrolled stormwater runoff on the local creeks, the Ottawa River and Petrie Island Beach.
  • This area of the Eastern Subwatersheds is roughly bounded by Trim Road to the east, the Greenbelt to the south, Conroy Road to the west and the Ottawa River to the north.
  • A subwatershed is defined as all of the lands that drain to a particular creek. In this case, the Eastern Subwatersheds are made up of all the lands that drain to:
    • Taylor Creek
    • an area that drains directly to the Ottawa River known as the Queenswood catchments
    • Bilberry Creek
    • Voyageur Creek
    • the urban areas of Green's Creek
    • and the urban tributaries of Green's Creek which are:
      • Cyrville Drain
      • Mather Award Drain
      • and McEwan Creek.
  • Much of the urbanized area within the Eastern Subwatersheds developed with little or no stormwater management.

Slide 8: What is stormwater management retrofitting?

  • Stormwater management retrofitting refers to the addition of measures into established older neighbourhoods that were built without the infrastructure to properly manage stormwater.
  • In the Eastern Subwatersheds, these impacts include degraded water quality in the creeks and Ottawa River that contributes to a higher number of closures at Petrie Island Beach, and increased flooding and erosion in the creeks that threaten property and infrastructure.
  • The challenge of stormwater management retrofitting is to identify effective measures that can be implemented when there are often limited opportunities available.

Slide 9: Stormwater Management Retrofit Measures

  • Stormwater management retrofit measures are classified by where they are located within the storm drainage system.
  • The first type of measure is called lot level. These measures are located at the source of runoff, that is, on the lot. They reduce the amount of rainfall that runs off and prevent pollutants from being carried off the lot. Lot level measures are considered to be the first line of protection in maintaining or restoring the health of a watershed. Though each lot may be relatively small in size, the use of lot level measures across many properties produces a cumulative benefit.
  • Typical lot level measures include: rain barrels or cisterns that harvest rainfall for later use on the property; rain gardens and other absorbent landscaping measures that capture and infiltrate runoff; green roofs; and the use of various permeable materials for the construction of driveways and parking lots.

Slide 10: Stormwater Management Retrofit Measures

  • Conveyance measures follow lot level measures. These measures collect and accumulate runoff from individual lots and transport it to the drainage system's outlet, usually the closest creek or river. Conveyance measures include drainage ditches, swales, storm sewers and the road allowance.
  • Conveyance retrofits include perforated or "leaky" pipes and curb extensions that treat and absorb runoff through the use of soils and plantings called bioretention. Here is an example of a conveyance retrofit that the City is now implementing on Sunnyside Avenue in Old Ottawa South. This retrofit design is a combination of bioretention and a perforated pipe system that will be constructed in a few locations by extending the existing curb and narrowing the paved portion of the roadway. This design will capture stormwater runoff from the roadway, cooling it down, treating and infiltrating it.

Slide 11: Stormwater Management Retrofit Measures

  • Next in line are End-of pipe measures that are located at the end of the storm sewer system, where it outlets to the nearest creek or river. End-of-pipe measures are larger scale facilities that receive the accumulated runoff collected by storm sewers. They provide treatment to improve the quality of runoff before it is discharged and can also store the runoff to avoid flooding impacts.
  • End-of-pipe measures include constructed wetlands and ponds. The stormwater management pond recently constructed near the downstream end of McEwan Creek is a good example of an end-of-pipe retrofit.

Slide 12: Stormwater Management Retrofit Measures

  • Stream rehabilitation measures: At times it may be necessary to consider in-stream measures that improve a stream's ability to receive urbanized runoff at the same time as enhancing its natural features and functions.
  • Such measures can include re-building sections of the stream, creating off-line pools for floodplain storage, and cutting down banks to re-connect an eroded channel with its floodplain. While the intent is to avoid hardening the stream as much as possible, this is sometimes unavoidable if infrastructure or property is threatened by ongoing erosion.

This is the end of Part 2. Please proceed to Part 3 for an overview of existing conditions in the study area.

Slide 13: Existing Conditions

  • As mentioned earlier, urban development within the Eastern Subwatersheds has occurred over the last few decades, much of it predating stormwater management requirements. This development has had an impact on the creeks, the Ottawa River and Petrie Island Beach. The following section provides an overview of the existing conditions of the Eastern Subwatersheds today.

Slide 14: Built Environment

The urban area within the Eastern Subwatersheds is about 7,200 hectares. The existing urban land use is:

  • 36% residential
  • 26% institutional/commercial/industrial
  • 20% transportation and
  • 18% open space.

There are about 650km of storm sewers in the study area, 90 storm sewer outfalls that drain to the local creeks or directly to the Ottawa River and about 24 existing stormwater management facilities.

Slide 15: Hydrology

  • Percentage imperviousness is a measure of how much of the subwatershed is covered with hard surfaces. For the Eastern Subwatersheds the average imperviousness ranges from about 29% for Voyageur Creek to about 38% for Mather Award Drain and 49% for Cyrville Drain.
  • Voyageur, Taylor, and Bilberry Creeks and the urban tributaries of Green's Creek (which are Cyrville Drain, Mather Award Drain, and McEwan Creek) have flashy responses to rainfall: in other words, when it rains, stormwater runs off very quickly, resulting in high peak flows and velocities that erode creek banks.
  • The hydrology of an urbanized watershed – or how water moves - differs greatly from how it moves in a natural subwatershed. Stormwater management retrofitting aims to more closely mimic natural hydrologic processes through the application of various measures.

Slide 16: Stream Processes

  • Many of the Eastern Subwatersheds' headwater streams have been eliminated or piped. Headwater streams are the smaller tributaries located in the upper watershed of a creek or river. These small streams are important to the overall health of creeks and rivers.
  • Bank erosion is common along many reaches of the creeks and drains, in some cases, increasing risk to infrastructure located within the creek corridors. Creek banks range in height from about 1 to 3 metres and valley heights or steep slopes range from 3 to 15 metres.
  • Cyrville Drain and Mather Award Drain are urbanized tributaries of Green's Creek and have been straightened and widened or deepened over the years. Sections of Cyrville Drain and McEwan Creek have been piped. The downstream reach of Voyageur Creek has also been enclosed in a large storm sewer.
  • Implementation of stormwater management retrofit measures will contribute to more stable creeks by slowing down stormwater, reducing runoff, and / or rehabilitating eroded banks.

Slide 17: Water Quality

  • The water quality in the Eastern Subwatershed creeks is characteristic of many urban watercourses.
  • The levels of bacteria, chlorides, nutrients and heavy metals in the creeks have been found to exceed the Provincial Water Quality Objectives.
  • The water quality at Petrie Island Beach often exceeds the swimming guidelines.
  • Although stormwater runoff from the Eastern Subwatersheds affects Petrie Island Beach, water quality at the Beach can also be affected by combined sewer overflows, flow patterns in the Ottawa River, and water fowl along the shoreline. Through the Ottawa River Action Plan, the City has already implemented measures that have led to significant decreases in combined sewer overflow volumes. Between 2006 and 2012, Combined Sewer Overflow volumes decreased by seventy per cent. For more information about how the City is addressing combined sewer overflows, choose the Ottawa River Action Plan link on the introductory page of this study's website.
  • Stormwater management retrofitting will improve water quality in the Eastern Subwatershed creeks and the Ottawa River.

Slide 18: Aquatic Ecology

  • The aquatic habitat is degraded due to uncontrolled stormwater runoff.
  • High peak flows and volumes of runoff have caused instability and a low diversity of aquatic habitat.
  • Aquatic habitat is also affected by poor water quality, channelized creeks and lengthy creek enclosures.
  • Sampling for fish has revealed a variety of cool and warm water fish species in Taylor, Bilberry and Voyageur Creeks. Fish sampling in the urban tributaries to Green's creek has yielded warm water species.
  • Stormwater management retrofitting and stream rehabilitation projects will reduce the impacts of uncontrolled stormwater runoff on fish habitat.

This is the end of Part 3. Please proceed to Part 4, the final part of this presentation. Part 4 provides an overview of the study process and schedule.

Slide 19: Study Process

  • The existing conditions of the Eastern Subwatersheds provide an understanding of where we are today.
  • Where we want to be and what we hope to achieve with the Stormwater Management Retrofit Study is expressed by the proposed study objectives, which include improving water quality, reducing flooding and erosion, improving the health of the creeks and Ottawa River and increasing public awareness of the importance of stormwater management. For more information about the proposed study objectives, please refer to the Study Objectives link on the introductory page of this study's website.
  • The Stormwater Management Retrofit Plan is the way we get there. It will identify the actions we need to take to achieve the study objectives. Developing the Draft Retrofit Plan has included these steps:
  1. A range of stormwater management retrofit scenarios was defined: The retrofit scenarios consider different amounts and combinations of retrofit measures. The scenarios emphasize lot level and conveyance measures and also include end-of-pipe measures. Different scenarios depend on the retrofit opportunities that have been identified by the study.
  2. Each of these retrofit scenarios has been evaluated by how well it meets the study objectives. For example, what are the benefits and costs of each scenario? Which scenario is preferred by the residents of Ottawa? How easy (or difficult) will each scenario be to implement?; and lastly,
  3. A draft Preferred Stormwater Management Retrofit Plan for the Eastern Subwatersheds has been identified. The draft Preferred Retrofit Plan consists of specific projects and programs to be implemented and the estimated cost and time frame for doing so. Further details about the draft Preferred Retrofit Plan and how it was arrived at can be viewed at this study's website.

Slide 20: Study Schedule

  • During the summer of 2014, after addressing comments received from the online Information Session, the Eastern Subwatersheds Stormwater Management Retrofit Study will be completed.
  • In the late fall of 2014, the recommended Eastern Subwatersheds Stormwater Management Retrofit Plan will be presented to the City of Ottawa Environment Committee and City Council for approval.

Slide 21: What Do You Think?

  • Please let us know what you think. You can do so by clicking on the "feedback" link on this study's website. Thank you for your interest. We look forward to hearing from you.

Frequently asked questions

The Eastern Subwatersheds Stormwater Management Retrofit Study is one of 17 projects in the City's Ottawa River Action Plan (ORAP)

What are the Eastern Subwatersheds?

The Eastern Subwatersheds cover an area of about 150 square kilometres in the east end of the City of Ottawa. A subwatershed is defined as all of the lands that drain to a particular creek. In this case, the Eastern Subwatersheds are made up of all of the lands that drain to Taylor Creek, Bilberry Creek, Voyageur Creek and Green's Creek and an area that drains directly to the Ottawa River known as the Queenswood catchments. This area is roughly bounded by Trim Road to the east, the Greenbelt to the south, Conroy Road to the west and the Ottawa River to the north.

Study Area: Eastern Subwatersheds

North to South, the Eastern Subwatersheds extend from the Ottawa River to Leitrim Road. East to West, the study area extends from Trim Road to Bank Street.

Why is a Retrofit Plan required for the Eastern Subwatersheds?

Much of the urbanized area within the Eastern Subwatersheds was developed with little or no stormwater management. When it rains in these areas, stormwater runs off roofs, roads and parking lots, is conveyed in storm sewers and discharged uncontrolled to the local creeks, or directly into the Ottawa River. Uncontrolled stormwater carries a host of pollutants and leads to large volumes of runoff and higher peak flows in streams. This affects water quality, increases erosion, degrades fish habitat, threatens infrastructure, and contributes to closures at Petrie Island Beach.

ORAP identified the Eastern Subwatersheds as a priority area to address these impacts of uncontrolled storm water runoff. The Retrofit Study will identify a long-term plan to:

  • Improve water quality in the local Creeks and the Ottawa River
  • Reduce flooding and erosion in the Creeks
  • Improve the health of the Creeks
  • Contribute to reduced closures at Petrie Island Beach.

What are the Retrofit Study's objectives?

The objectives *of the study are to:

  1. Reduce flood risk to public health and safety and to property along the Creek** corridors
  2. Reduce erosion impacts in the Creek corridors that are detrimental to property, infrastructure and stream habitat
  3. Re-establish a more natural hydrologic cycle for the Eastern Subwatersheds
  4. Improve water quality in the Creeks and the Ottawa River by reducing the impact of stormwater runoff
  5. Reduce the impacts of stormwater runoff on Petrie Island Beach
  6. Protect, enhance or rehabilitate natural features and functions along the Creek corridors
  7. Increase public awareness about stormwater management and public involvement

* Note: the numbering is for convenience and does not indicate priority.
** The Creeks referenced include Bilberry, Voyageur, and Taylor Creeks and the urbanized tributaries of Green's Creek (MacEwan Creek, Cyrville Drain and Mather Award Drain).

How is the Retrofit Study being carried out?

The Retrofit Study is being conducted as a Master Plan under the Municipal Class Environmental Assessment (EA) process. It will look at how different stormwater management measures can be retrofitted into existing communities.

The Study will:

  • Define a range of retrofit scenarios (different combinations and amounts of the measures described below)
  • Evaluate how well they meet the study objectives
  • Identify a Preferred Retrofit Plan for the Eastern Subwatersheds.

What stormwater management measures will be considered?

SWM measures are classified by where they are located within the storm drainage system and include:

Lot level: These measures are located at the source of runoff, that is, on the lot. They reduce the amount of rainfall that runs off and prevent pollutants from being carried off the lot. Lot level measures are considered to be the first line of protection in maintaining or restoring the health of a watershed. Though each lot may be relatively small in size, the use of lot level measures on many properties can combine to provide a cumulative benefit.

Typical lot level measures include: rain barrels or cisterns that harvest rainfall for later use on the property; rain gardens and other absorbent landscaping measures that capture and infiltrate runoff; green roofs, and the use of various permeable materials for the construction of driveways and parking lots.

Downspout Re-direction

Example of downspout re-direction

Rain Barrels

Example of a rain barrel in a residential area

Rain Gardens

Example of a rain garden in a residential area

Permeable Materials

Example of permeable pavers in a parking lot

Conveyance measures follow lot level measures. These measures collect and accumulate runoff from individual lots and transport it to the drainage system's outlet, usually the closest creek or river. Conveyance measures include drainage ditches, swales, storm sewers and the road allowance. Conveyance retrofits include perforated or leaky pipes and curb extensions or bump-outs, that treat and absorb runoff via the use of soils and plantings called bioretention.

Street Narrowing

Example of a street narrowing where bioretention structures were implemented within the right of way

Next in line are End-of pipe measures, located at the end of the storm sewer system, where it outlets to the nearest creek or river. End-of-pipe measures are larger scale facilities that receive the accumulated runoff collected by the conveyance system. They provide treatment to improve the quality of runoff before it is discharged and can also store the runoff to avoid flooding impacts. End-of-pipe measures include constructed ponds and wetlands.

Wet pond

Wet pond in a residential area

Stream rehabilitation measures: At times it may be necessary to consider in-stream measures that improve the stream's ability to withstand urbanized flows while at the same time maintaining its natural features and functions. Such measures can include re-building sections of the stream, creating off-line pools for floodplain storage, and cutting down banks to re-connect an eroded channel with its floodplain. While the intent is to avoid hardening the stream as much as possible, this is sometimes unavoidable if infrastructure or property is threatened by on-going erosion.

Oil and Grit Separator
Example of an Oil and Grit Separator

All of these types of measures will be considered in the preparation of the SWM Retrofit Plan.

How can you get involved?

For more information about the Retrofit Study, please watch the video on this website and review the other information provided. Let us know what you think by providing your comments. If you have any other questions or would like your name added to the Study's mailing list please contact Laurent Jolliet.

Contact person

If you have any questions or would like your name added to the study's mailing list please contact:

Laurent Jolliet, P. Eng.
Senior Project Manager
Planning, Infrastructure and Economic Development
110 Laurier Avenue West, 3rd Floor
Ottawa, ON K1P 1J1
Tel.: 613-580-2424, ext. 17149
Email: Laurent.Jolliet@ottawa.ca