Neighbourhood Meeting, December 1 2022

We understand that not all residents will be able to attend the neighbourhood meeting. The information is presented here for your information, and we encourage you to connect with our project team directly if you require this information in an alternate format, or if you have questions. The presentation boards are also available.

Date: December 1, 2022
Time: 6:30 p.m. – 8:30 p.m.
Location: Keatsway Public School: 323 Keats Way, Waterloo, ON N2L 5V9

This project involves the restoration of a portion of Clair Creek between Keats Way and McDougall Road to reduce the risk of erosion, flooding and damage to private property in the area. Recommended works include replacing retaining walls supporting the creek bank, and installing a new storm bypass along Keats Way to reduce flooding risks.

Project priorities

Protect existing building structures
Reduce risk to public safety
Reduce risk of flooding to the adjacent properties

In the fall of 2021, the City reached out to the neighbourhood to gather information about property owner’s experiences. A number of properties had experienced flooding from Clair Creek, while some properties experienced no flooding at all. This information was used to help determine the need and the scope of the project and to help focus efforts on areas that were experiencing the worst flooding.

Existing site conditions and current flood mapping

The section of Clair Creek from Keats Way to McDougall Road is defined as “a confined channel with gabion basket bank treatments”. The existing municipal storm sewer on Keats Way, west of Keats Walk, discharges to a tributary via a culvert and flows around the existing residential properties on Keats Way Place. The tributary ultimately meets with Clair Creek, west of McDougall Avenue.

Generally, the creek channel consists of gabion baskets along the majority of the banks of the creek, with grassed areas and trees on either side of the overbanks. The gabion baskets are failing in multiple locations along the creek corridor, within 5 metres of buildings on private property in certain areas.

Our project team has completed a great deal of preliminary work to help come up with the best options for the creek restoration. That work included an assessment of plants and animals in the area (no species-at-risk or species-of-conservation-concern plants or animals were identified, and 577 trees were recorded), and looking at how the creek flow changes. The ground and subsurface were assessed, and buried utilities were located. Flood modelling and mapping was also done.

This area is currently recognized by Grand River Conservation Authority (GRCA) as floodplain. The floodplain is based on regional storm events (Hurricane Hazel). Flood modelling and mapping helps us identify areas that may be at risk of flooding during severe storms. Residential properties in the area are regulated by the GRCA. This means that any construction work or development activities on these properties will need a GRCA permit, in addition to a building permit or other approvals from the City and other agencies.

As part of the flood modelling, we determined that a creek bypass would be needed to prevent flooding on residential properties during a 5-year and 25-year storm event.

Given the information gathered by the project team, we then looked at alternatives for restoration using the following considerations:

Access to the area through properties for construction, and how much the alternative will cost to construct and maintain.
Minimizing impacts to buildings and roads.
No increase to flooding or erosion.
Maintaining existing infrastructure, such as pedestrian crossings over the creek and the two storm sewers from Keats Way and Keats Way Place that empty to the creek
Natural channel design, with appropriate landscaping to stabilize the creek banks
Consideration for natural habitats and fish passage through the corridor.

Creek stabilization

The preferred method for creek restoration will involve the use of soft armoured walls and living walls where appropriate, as well as hard armoured walls.

Soft armouring techniques such as a “living wall” can be used to reinforce the slope and provide erosion protection in areas where there is sufficient space and less risk to public safety or flooding. In some parts of the study area, tree cover over portions of the creek might make it difficult to grow vegetation on the slope. In those areas we would use appropriate grass seed mix and plants that thrive in partial sun or shaded areas.

Using soft-armouring in areas where the existing retaining wall is within 5 metres of a residential structure would be difficult. Therefore, in those areas hard-armouring would be used.

A typical armoured stone retaining wall consists of a combination of hard and soft armourstone. It includes a hard armoured wall, which consists of large, rectangular blocks of stone that are placed on top of each other forming a wall along the streambank. The large rectangular stone blocks make up the main structural component, with the stone’s size and weight it can help to prevent damage from flowing water.

Property owners can contact the project team directly to discuss which technique will be used on their property.

Creek bypass

Four options were developed and reviewed for the proposed bypass:

Option #1: Do nothing for bypass, and only restore the creek
Option #2a: Discharge to existing McDougall Road Culvert
Option #2b: Discharge directly to Clair Creek
Option #3: Underground storage with controlled discharge

Doing nothing is not recommended, since restoring the creek will not address flooding concerns during large storm events. The three other options all provide considerably better flood control during a major storm event, with option 2a being preferred as the most cost-effective, and least invasive for construction.

Construction timeline and information

Winter 2023: start creek restoration
Spring 2023: bypass construction (continues through Summer 2023)
Summer 2023: continue and finish creek restoration

Construction work will involve:

Installation of cofferdams
Temporary lane closures on Keats Way
Removals (of existing gabion baskets, landscaping, etc.)
Installation of the preferred solution

Additional removals will include some trees, landscaped areas and some creek crossings. A Tree Protection Plan will be in place for those trees remaining in the project area, and landowners will be notified to remove any plantings or gardens that they want to retain before construction begins. The project team will work with landowners to restore impacted areas. Several existing creek crossing structures will also need to be removed for the work to be done. Discussion will be held with landowners to wish to maintain a creek crossing so that no damage will be done to the restoration work.

Our goal is to maintain work within easement as much as possible. If workers are required to work outside the easement, homeowners will be contacted.

Construction along Keats Way will include lane closures along portions of the street (along the school) and traffic control between Keats Walk and McDougall Road would be used as needed to ensure safe passage for pedestrians and cyclists, and maintain two-way one-lane traffic through the work area. The work would not impede access to Keats Walk, Karen Walk, and Keats Way Place. Bus stops will also be relocated. Traffic control plans will be finalized before the start of construction and landowners will be notified.

Immediate next steps for this project involve completing the detailed design of the work, including construction drawings and specifications, tendering of the construction work and approval of the tender, followed by construction.

If you have any questions, our project team will be happy to address them.