Protecting Edmonton's Water Treatment Plants from flooding

• 2018 — Stormwater Integrated Resource Plan presented to Edmonton City Council
• 2020-2021 — Shared outcomes created with communities
• 2021-onward — community and Indigenous engagement on values, barrier design, vegetation management, archeological monitoring and construction
• 2023 — presentation to Edmonton Utility Committee and approval by Edmonton City Council
• 2023 — Final design selection process for WTP flood barriers
• 2024-2025 — current phase of engagement on art and interpretive elements
• 2024-2027 — Construction at the WTPs

• Spring 2025 — start of excavation on flood wall
• Q2 2025 — start of foundations
• Q3 2025-Q4 2026 — construction of concrete wall
• September 2025-Q2 2027 — construction of grass-covered embankments
• Q3 2026 — Outfall flood gates completion 

• Now-Q2 2026 — excavation
• Q2 2025 — start of foundations
• Q2 2025-Q4 2025 — construction of concrete wall
• May 2025-Q4 2025 — substantial construction of grass-covered embankments (a small portion will be completed later, by Q3 2026)
• Q3 2026 — Outfall control gates completion 

• Construction areas will be fenced or marked as restricted areas. We will take every precaution to ensure the safety of the public and our staff, and we request your assistance in keeping clear of the construction site and equipment. 
• We continue to work with our contractors to ensure we meet the City of Edmonton’s Community Standards Bylaw, mitigating noise, air, traffic/pedestrian, and other impacts. 
• Typical hours of work will be from 7 a.m. – 7 p.m., Monday to Friday. If required, these hours may be extended into the evenings/weekends.
• Where possible, we will notify local communities ahead of any work that is expected to have high-than-normal impacts (such as noise, traffic, dust, timelines, etc.).

The project requires construction access and activities on and near the trails that run directly east and south of the Rossdale Water Treatment Plant. While we did review the possibility of re-routing trails with the City of Edmonton, we learned that this would not be feasible. Therefore, there will be the following trail closures: 

• Starting spring 2025, the stretch of trail along 101 Street from 94 - 95 Avenue will be redirected one street to the east.
• Starting fall 2025, the trail to the south of the Rossdale WTP will be closed and trail users will be redirected to go around the plant.  

Review the map for more details on the trail closures and alternate routes.

For your safety, please observe all barriers and signage and keep away from work areas.

We recognize the concern that the implementation of this project may lead to the loss of some trees and vegetation near the barriers of both water treatment plants.

Rest assured, we have plans in place to replace the removed vegetation with an even larger area of greenery.

As part of developing the Vegetation Management Plan, EPCOR asked interested Indigenous Nations to form a Traditional Ecological Knowledge working group to provide meaningful input to vegetation management at the two water treatment plant sites.

In the first half of 2023, EPCOR held several meetings to walk the sites, discuss shared values and naturalization strategies, and gather feedback to ensure these lands were cared for. We have incorporated this advice into our vegetation management plan, which will target a return to a natural Prairie Parkland ecoregion as appropriate. There is also a strong desire for harvestable berries and ceremonial sites for Indigenous teachings.

All together, we reached out to more than 30 Nations to engage on vegetation and construction, and have held several pipe ceremonies at the Rossdale Water Treatment Plant to help ensure we are moving forward in a good way.

Supporting urban Indigenous ceremony

We provided some of the removed trees as part of this project to kihcihkaw askî for ceremonial and traditional uses. kihcihkaw askî provides a natural setting in Edmonton for Indigenous Peoples, groups, and communities to host ceremonies, sweat lodges and facilitate intergenerational learning.​​​​​​​​​​​​​​

Developing barriers to protect equipment and water reservoirs

To protect the Rossdale Treatment Plant in a situation where the North Saskatchewan River overtops its banks, our engineering studies have shown that permanent flood barriers are needed in key locations around the facility. Once constructed, these barriers will limit potential damage to critical equipment and drinking water reservoirs, and ensure that we can resume producing clean drinking water as quickly as possible after a flood.

We compiled and assessed all of the perspectives, suggestions, and comments received during community engagement. The following map shows the a combination of grass-covered embankments and flood walls that will be built around Rossdale to meet technical requirements, reduce the impacts to vegetation and minimize the cost to rate payers.

Two types of flood barriers can be used to protect the water treatment plant in the case of a major flood.

With either type of flood barrier (wall or grass-covered embankment) buffer zones are in place that restrict the type of vegetation that can be replanted. The buffer zone is about 5m from the wall or end of the embankment slope. This is to maintain the structural integrity of the barrier. Sod or naturalized grasses are the only option for replanting here. Roots from large vegetation can encourage burrowing animals.

Developing barriers to protect equipment and water reservoirs 

To protect the E.L. Smith Water Treatment Plant in a situation where the North Saskatchewan River overtops its banks, our engineering studies have shown that permanent flood barriers are needed in key locations around the facility. Once constructed, these barriers will limit potential damage to critical equipment and drinking water reservoirs, and ensure that we can resume producing clean drinking water as quickly as possible after a flood.

We have compiled and assessed all of the perspectives, suggestions, and comments received during community engagement. The following map shows a combination of grass-covered embankments and flood walls that will be built around E.L. Smith to meet technical requirements, reduce the impacts to vegetation and minimize the cost to rate payers.

Two types of flood barriers can be used to protect the water treatment plant in the case of a major flood.

With either type of flood barrier (wall or grass-covered embankment) buffer zones are in place that restrict the type of vegetation that can be replanted. The buffer zone is about 5m from the wall or end of the embankment slope. This is to maintain the structural integrity of the barrier. Sod or naturalized grasses are the only option for replanting here. Roots from large vegetation can encourage burrowing animals.

As part of our plan to protect our water treatment plants during a major flood event, we are working to increase the protection of critical assets on site or
relocate them.

We're working on a comprehensive risk assessment and a review of flooding pathways to ensure equipment that is critical to the operation of the water treatment plant is protected in case of a major flooding event. This work may involve installing barriers, moving equipment up higher, or making equipment submersible. This work will all take place within existing buildings on the site and within our fence line.

What does "critical" mean?

Some critical assets at the Rossdale site include transformers that supply power to the water treatment plant, underground drinking water storage reservoirs, and underground tanks that contain additives used in the water treatment process. Others include pumps, sensors and valves that could fail if they were to get wet. See the water treatment process in action.

Another part of our plan to protect our water treatment plants during a major flood event includes preventing river water from backing up into the water treatment plant through drainage pipes that discharge to the river.

Our water treatment plants have piping systems that collect rainwater and process water to be returned to the river. Today, those are open outfalls that could allow river water to flow in the opposite direction during a flood. If that were to happen, we would see surcharging from manholes that could allow water to reach sensitive equipment. We would also see untreated river water backing up into the treatment plant, contaminating the process with untreated water and the harmful microorganisms we are trying to remove.

We plan to install valves in the piping systems that we can close in the event of an elevated river level to prevent this from happening. Work is currently under way within existing buildings on the site and within our fence line.

As a precursor to the project, EPCOR invited community members, Indigenous communities and First Nations, special interest groups, residents, recreational user groups, community league representatives and individuals who have interest in the WTPs to help es​tablish five shared outcome statements. These shared outcomes will guide our work at the Rossdale and E.L. Smith Water Treatment Plants moving forward.

Following this shared outcome work, we  undertook three phases of community engagement between May 2021 and September 2023 to the REFINE level in our public engagement framework. The goal of engagement was to seek community members’ input to help us improve the quality of the project design.

We conducted community engagement using a variety of techniques, including online and in-person workshops, one-on-one meetings, and regular project communications. 

• We first sought to understand how community members use the spaces around the water treatment plants, and what they value most in terms of design. 
• We talked with local community members, rights-holders and Indigenous Nations and communities, sharing information about permanent flood barriers planned for installation around the water treatment plants.
• We collected feedback about how the barriers will be experienced by those who live, work and recreate in the areas around the facility. 
• We heard from a number of community members who shared their perspectives on which design considerations are important for EPCOR to consider while building flood barriers. 

​​In late 2024, we started Phase 4 of the engagement process, convening a panel of Indigenous and Rossdale community members to recommend an approach to art and interpretive elements for barriers at Rossdale. 

We recognize the archaeological and historical significance of the sites of the plants, which predate the City of Edmonton itself. It was important to EPCOR that we seek out, hear, and include the perspectives of more than 30 Indigenous Nations and communities with an interest in these lands and will continue these conversations throughout this project.

We gathered Indigenous feedback and responses through in-person walking tours, virtual information sharing and guidance-seeking workshops, monitoring activities and one-on-one conversations.

Did you know? 

EPCOR is aligning with the principles of OCAP® (Ownership, Control, Access, Possession) for this work, and continues to work with participating Knowledge Keepers and Indigenous Nations and communities to ensure protocols are in place for appropriate management of the Indigenous knowledge that is shared.​

The following themes emerged through Indigenous engagement: 

• ​The importance of Water
• Consideration for the Environment, tree removal, replanting
• Allowing for interaction with the land, maintain harvesting opportunities
• The many histories and stories of the areas 
• The importance of Treaty

As we move forward, we will continue to work with Nations to address these key themes. EPCOR will prioritize reconciliation: working collaboratively with Indigenous Peoples to reconnect with their historic lands, by creating opportunities for monitoring archeological work, shared learning, conducting ceremony, and traditional plant harvesting. 

Read the reports below for more information on how engagement was conducted, what we heard and how we addressed feedback. 

• Read the full Rossdale report
• Read the full E.L. Smith report
• Read the full Indigenous engagement report