Feedmill Creek Stream Rehabilitation Measures

Class Environmental Assessment On-line Open House November 24, 2016

Feedmill Creek Stream Rehabilitation Measures

Class Environmental Assessment On-line Open House November 24, 2016

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Welcome

The City of Ottawa is undertaking a municipal Class Environmental Assessment (EA) study to determine the preferred approach to mitigate the impact of future developments on Feedmill Creek.

This on-line Open House will review:

• Study background and project need;

• Purpose of the Class EA process;

• Existing environmental conditions;

• Project alternatives and preferred solution;

• Opportunities for public input; and

• Next steps and project schedule.

Pictures of Feedmill Creek

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Background

The City of Ottawa has undertaken a Municipal Class Environmental Assessment (Class EA) for the stream rehabilitation measures proposed in the Feedmill Creek Stormwater Management Criteria Study. This study was required to confirm quantity control criteria for the remaining future development in the Feedmill Creek subwatershed. As part of the results, an optimal combination of stormwater management criteria was developed in order to mitigate the impacts of future development on stream function, peak flows and water level including erosion control and flood control.

The study is being implemented under Schedule B of the Municipal Class Environmental Assessment which will identify a preferred alternative and functional design. This consultation is required per the Class EA process;

Feedmill Creek Study Area

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Existing Environmental Conditions

The Feedmill Creek watershed is primarily comprised of soils with poor infiltration characteristics;

The channel does not have the capacity to absorb any increase in in-stream erosion potential;

Blanding’s turtles have been observed by City staff, residents and Provincial biologists at several locations along Poole Creek and within Stittsville;

Headwater wetlands contribute to creek baseflow;

The creek supports a tolerant cold water fish community and a diverse warm water fishery;

Temperatures remain in the range suitable for cold water species and are generally 3-5C lower than Carp River

Narrow and fragmented deciduous forest riparian borders provide some watercourse buffering and limited corridor and wildlife functions.

Pictures of Feedmill Creek

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Project Alternatives

Alternative 1: “Do Nothing”

Alternative 2: “Detention & Retention” + In-stream measures

Stormwater Management Pond (Detention)

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Bioretention Cell (Retention)

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Cross-Van Design (In-stream Measure)

Pictures illustrating Alternative 2: Detention, Retention and an Example of In-stream Measure

Evaluation of Alternatives

Alternative 1: “Do Nothing”

Alternative 2: “Detention & Retention” + In-stream Measures

Criteria Alternative 1: "Do Nothing”

Alternative 2: “Detention & Retention + In-stream ”

Environmental Construction impacts N/A Vegetation removal to access site; some disturbance to

creek bank/toe of slope to implement the measures Fisheries Continued erosion negatively impacts fish habitat Existing fish habitat to be enhanced; improved riparian

vegetation Blanding’s Turtle Gradual degradation of the natural habitat Existing turtle habitat to be maintained and improved Social Impact of erosion Continued toe erosion will reduce stability of

existing slope and eventually impact existing table lands and future developable lands

Existing table lands and future developable lands protected by the proposed SWM measures and in-stream rehabilitation measures

Impact on private property N/A Minor disruption during construction period

Financial Estimated project cost N/A in short-term; loss of table land in long-term;

damage to existing infrastructure Cost of 1.6M for in-stream work to be funded by future developers located within Feedmill Creek Subwatershed

Other Benefits N/A N/A

Preferred Solution

Alternative 1 (“Do nothing”) is not a feasible option as continued erosion will ultimately impact the creek and future flows will exceed MTO’s criteria at the Highway 417;

Alternative 2 allows to mitigate the impacts of future development on stream function, peak flows and water level including erosion control and flood control;

Alternative 2 is selected as the preferred solution: • Detention:

• Control peak runoff from a 15 mm 3-hour Chicago design storm to 0.51 L/s/ha; • Control peak runoff from a 100-year 12-hour SCS Type II storm to 8.0 L/s/ha;

• Retention: • Control runoff from either a 10 mm or 5 mm rainfall on-site through

implementation of Low Impact Development (LID) controls

• In-stream rehabilitation measures

In-stream Rehabilitation Measures

Total Cost for In-stream Rehabilitation Measures: 1.58 M$

Reach 1

Reach 2

Reach 3

Reach 4 Reach 5

Reach 6

Reach Location

Figures Showing the Proposed In-stream Rehabilitation Measures for Each Reach

Opportunities for Public Input

Notice of Study Commencement;

On-line Open House (November 24 to December 9);

Ongoing public inquiry contacts;

Notice of completion

Next Steps

Confirm or revise preferred solution based on public input and agency comments;

Post Notice of Completion for 30 day public review period (early 2017);

Study approved by Council/Class EA posted early 2017;

Detailed design/approvals in 2017;

Construction of Project in late 2018 (TBC);

Thank you

Please provide your comments by mail/fax/email to the contact below on or before December 9, 2016

Laurent Jolliet, P. Eng.

Project Manager

Asset management

City of Ottawa

110 Laurier Avenue West, 4th Floor

Ottawa, ON K1P 1J1

Phone: 613-580-2424 ext. 17149

E-mail: laurent.jolliet@ottawa.ca

Fax: 613-580-2578