Lauderdale flood mitigation

Lauderdale is serviced with a mix of combined sanitary and storm lines, and separated sanitary and storm lines. In a combined sewer, both sanitary and stormwater flow together in the same pipe. There is no stormwater management facility in the neighbourhood, and the current overland (or surface drainage system) is not sufficient. There are several areas in this neighbourhood at lower elevation where water pools, which puts the Lauderdale community at risk of flooding during intense rainfall events.

There is limited green space in Lauderdale suitable for this drainage infrastructure. Due to its topographic location within the city, the Grand Trunk Off-Leash Dog Park collects stormwater from several areas within Lauderdale, as well as from areas as far west as 127 Street and as far north as 137 Avenue, during extreme rainfall events when the amount of rainfall exceeds the capacity of the local drainage systems.

Yes, several different dry pond location options were looked at; however, there is limited green space in Lauderdale. One of the alternative options that was considered was Grand Trunk Park. This area is not feasible from a technical perspective due to the major combined sewer line that runs directly underneath the park and the fact that Grand Trunk Park is three metres higher in elevation than the Grand Trunk Off-Leash Dog Park. Grand Trunk Park collects only the stormwater that falls directly on Grand Trunk Park; there is minimal stormwater that flows into Grand Trunk Park from other areas in Lauderdale.

According to the City of Edmonton, from May 1, 2019 to September 30, 2022, Grand Trunk Park is one of the City’s most heavily used sites in the northwest quadrant of Edmonton, and perhaps the City as a whole.

The project is currently in the preliminary design phase and, at this point, the design of the dry pond (exact location, size, shape, how steep/gentle the slopes are, etc.) has not yet been determined. The feedback gathered from dog park users and community residents, along with the technical requirements of the project, will help inform the final design of the dry pond.

During dry pond construction, we expect to keep a reduced area of the dog park open for use, along with the parking lot, with safety measures in place for park users. The size of the area able to remain open during dry pond construction will be based on the technical design requirements and community/dog park user feedback.

The specific footprint and size of the dry pond within the dog park has not yet been determined; however, the facility needs to be designed to accommodate the future LRT alignment, the dog park access road and parking lot.

A dry pond is built with standard safety measures. Many dry ponds in the City of Edmonton are built in school yards and include recreation facilities such as soccer fields and baseball diamonds. The sides are typically gently sloped, anywhere from five to ten feet in horizontal length for every one foot of vertical drop.

Dry ponds are graded so stormwater pools in specific areas first. This helps keep the majority of the area dry and drains more quickly when they do become flooded. Water that does collect in a dry pond drains very quickly, often between one to three hours after a heavy rainfall. The grates for the drains are designed to consider safety of pets and small animals that use the facilities.

The first few millimeters of rainfall heavily dilutes any contaminants from the roadway or other surfaces and washes them through the underground stormwater system early in a storm event.

As the rainfall continues there are less contaminates remaining on the roadway and other surfaces so the concentration of potential contaminates in the stormwater is significantly reduced.

If the rainfall becomes intense enough, and if the drainage system gradually becomes full, the dry pond will begin to collect stormwater. The water in the dry pond will be mainly rainwater with very low concentrations of any sediments or contaminants.

In the City of Edmonton, dry ponds are commonly used for recreation spaces such as soccer fields and baseball diamonds, and several are located in schoolyards.

There are 79 dry ponds across the city; three of which are off-leash dog parks (located in the Tweddle Place, Satoo and Meyonohk neighbourhoods).

EPCOR will be looking for feedback on enhancements such as agility and water play features for dogs, formal trails, landscaping, etc. The proposed enhancements are intended to not only meet the diverse needs of small and big dogs, but also add amenities for dog owners.

We are in the very beginning stages of community engagement for this project, which will include community and dog park user surveys and public information sessions to get a better understanding of the community’s and dog park users’ priorities for enhancements to the dog park once the dry pond is built. The feedback from the community and dog park users will be used to inform the final design of the dry pond.

The dry pond is part of EPCOR’s Stormwater Integrated Resource Plan (SIRP) which aims to reduce the risk of flooding in Edmonton neighbourhoods. The initiative prioritizes infrastructure investments to reduce the flood risks and potential impacts.

While local flooding data is one consideration, not all flooding events are reported to EPCOR. The SIRP initiative is based on multiple criteria, including system design, insurance industry data, environmental factors and public input.

Flood mitigation in the City of Edmonton is assessed from a city-wide perspective, factoring in future climate change risks. The goal of SIRP is to reduce the risk for property damage by having safe, managed facilities that collect large volumes of water created from severe storm events.

It can take anywhere from six to eight months to build a dry pond, including restoration, depending on the size.

Construction of the dry pond and storm infrastructure upgrades work is anticipated to start in 2023, after public engagement has been completed and final designs have been approved.

Residents and users can expect to see the contractor use a combination of excavators, loaders, skid steers, and tandem trucks, as well as other equipment. Details regarding traffic accommodations, construction impacts, and timelines will be provided in future notices as we get closer to the start of construction and confirm those details with the contractor.