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Sunnyside Flood Barrier Project

We're investing in Sunnyside, Hillhurst and along the Memorial Park Corridor to increase flood resiliency and create spaces that enhance the connection with the river, community and natural environment, while commemorating our heritage.

About the project

We know that building a permanent flood barrier is vital to help protect people, homes, and businesses in Sunnyside and Hillhurst from river flooding. We are committed to delivering a 1:100 level flood barrier.  This will help us manage flood water and avoid the type of damage we saw in 2013, while providing the building blocks for future climate resiliency.


The barrier’s location along one of Calgary’s most cherished corridors, is an important consideration. This space must be protected and where possible, enhanced. When designing and constructing the flood barrier, we have had a chance to build upon improvements to this area that have happened over the last 10 years and continue to improve the entire public space surrounding Memorial Drive N.W.  from 14 St. to Centre Street while adding critical flood protection. The new flood barrier will also provide the building blocks for future climate resiliency.

Work happening this year

Construction will begin in July of 2024 with the following activities taking place: 

Location Closure Details Status and Anticipated Schedule Impact
Walking trail between 10 St and 14 St   Trail closed. Use regional pathway. Anticipated to begin July 5 for one month.   Noise and dust from culvert installation.  
Right lane of EB Memorial Drive N.W. between 10 St and 14 St   Daily lane closures (9am to 3pm). Anticipated to begin July 22 for two weeks. Noise and vibration from sheet pile installation.  
Centre St to 9 St N.W.   Two EB lanes of Memorial Drive N.W. closed. Two-way traffic on WB Memorial Drive N.W.   Anticipated to begin late July for three months.     Noise, vibration and dust from pressure relief pipe installation.
Regional pathway along Memorial Drive N.W. between 10 St and 14 St Pathway closed.   Anticipated to begin in August for five weeks.   Noise and vibration from sheet pile installation.  
Around Prince’s Island Pedestrian Bridge   Pathway width reduced.   Anticipated to begin late July until the end of October.   Cyclists must dismount. Noise from concrete pile drilling.

Visit the Riley Area Construction Project page, here for information about weekly traffic closures and detour updates.

During construction, sections of the Bow River Pathway between 14 St N.W. and Centre St will be impacted. During this time, pathway users will be provided detours to ensure safety and connectivity. Pathway detour information can always be found here.

What will the Sunnyside Flood Barrier look like?

The flood barrier will include a combination of permanent flood walls and sheet walls as well as temporary deployable systems (i.e., sandbags, water filled tubes) and demountable flood walls. The barrier will be approximately 2.4 kilometres long.

Sheet Pile Flood wall

A permanent metal wall that is designed to hold back flood water. It is embedded below ground three-six metres deep to provide structural stability. The sheet pile wall is designed for space-constrained areas and minimizes the amount of construction disturbance and tree/shrub removal. Sheet pile is not recommended for certain areas of the barrier where it risks inhibiting the flow of groundwater from the community subsurface aquifers to the river. About half of the wall is made of sheet pile. 

Sheet Pile Flood wall
Note: this is a rendering only.

Concrete Flood wall

A permanent, freestanding wall, made of concrete, designed to hold back flood water. Concrete flood wall is another space-conscious barrier type but one that requires more construction disturbance area to excavate and place the concrete base. Concrete flood walls have been designated for areas that require free movement of groundwater beneath. 

concrete flood wall
Note: this is a rendering only.

Construction information session resources

The project team held an information session in October 2023 to provide details on flood barrier design and construction.

View the information boards , east alignment and west alignment drawings from the session for details.

The first phase of construction will focus on enabling work (early work that must be completed before barrier construction can start). As we work through the details with our design team and construction manager, we will share information on what enabling work will be taking place, the schedule for the work and any construction impacts the public could expect to see. During construction, we are committed to support and provide ways to move to and through the local Sunnyside/Kensington and Riley Area Communities that emphasize safe, accessible, and efficient movement. Please check back on our website for schedule and construction updates.  

Tree inventory and Removal

Removing a tree is always a last resort. However, to make improvements in the area, some tree loss is unavoidable. Approximately 337 tree removals are required as part of the project. 22 of those trees were removed in spring 2024 with the remainder being removed in 2025.

Many trees will be repurposed in:

  • Fish compensation projects
  • Habitat restoration work for fish and wildlife
  • The construction of planting beds and seating around Sunnyside and around Prince’s Island

In advance of the enabling works and main construction, our team took inventory, surveyed and completed heath assessments of each tree on site. We plan to replant 280 new trees and new flowers and shrubs. We have also made modifications to the original design of the flood barrier to minimize required tree removals.
For more information on Memorial Drive Trees, please visit Memorial Drive trees.

Bow River flooding - what's the risk in Sunnyside?

Homes, buildings and other infrastructure in Sunnyside are impacted when river flows reach levels of 927 m3/s (1:10). There is a 10 per cent chance of this occurring every year. Find out if your property is at risk of flooding​.

What measures will protect Sunnyside from future flooding?

To protect Sunnyside from future flooding, the Flood Mitigation Measures Assessment​ (FMMA) report, approved by Council in spring of 2017, recommended that a combination of mitigation solutions that work together to create a flexible and adaptable flood risk management program. Each piece of the strategy provides great benefits independently, but together, they ensure the most effective flood protection strategy.

Below is a summary of this multi-measure approach to building flood resiliency that includes the construction of a new upstream reservoir, as well as changes to the TransAlta’s Ghost Reservoir and the construction of community-level flood barriers.

What is the level of protection for the barrier?

After working with the community and completing a Triple Bottom Line evaluation to explore different options for a flood barrier in Sunnyside, Council approved the 1 in 100-year flood barrier height that will help protect people, homes and businesses in Sunnyside/Hillhurst from river flooding.

Benefits of the 1 in 100-year flood level barrier height

  • Reduces the 2013-level flood risk, which will be further reduced by current and future upstream reservoirs on the Bow River.
  • Less disruptive to the community look and feel
  • Increases the ability to protect vulnerable populations
  • Meets the provincial and federal flood standard (1 in 100-year)
  • Provides the building blocks for future climate resiliency

Is the barrier expandable to a 1:200-year service level?

Following direction from Council, the barrier will be built to withstand the 1:100-year flood event having a peak flow rate of 2090 m3/s at Sunnyside. This is greater than the recorded peak flow rate of the 2013 flood that was 1840 m3/s.  The 1:200-year event peak flow rate is 2710 m3/s.  To withstand the 1:200-year flood the barrier would need to expand in length by approximately 1 km and in height by 0.7 m along its entire length. 

Still, designers investigated modifying certain components of the flood barrier to simplify possible future expansion of the barrier within its footprint and within its approved budget.  Wider concrete footings, deeper pile depths and greater vegetation setbacks were considered but did not offer appreciable current benefit (i.e. not cost effective) for a possible future expansion.  Also, for a given length and height, there are numerous consequent design decisions that would need to be reconsidered if the level of service was to be increased. Such considerations are better addressed at the time of expansion. 

Will the City impose any building restrictions in Sunnyside and Hillhurst if the barrier is not sized protect from a 1:200 flood?

The City is exploring how to regulate land use in river valleys through the Calgary River Valleys Project This work follows, the Government of Alberta’s update of Flood Hazard Area maps for communities across the province.  This will ultimately lead to an update of the Land Use Bylaw. Flood Hazard maps are based on the 1:100-year flood and include ‘protected areas’ where flood protection is provided, such as Sunnyside and Hillhurst. Appropriate regulation for such areas is being explored. Land use regulation may change in Sunnyside or Hillhurst, but it is not affected by the barrier’s height above the 1:100-year flood.

Flood barrier height recommendation for Sunnyside

After working with the community and completing a Triple Bottom Line evaluation to explore different options for a flood barrier in Sunnyside, Council approved the 1 in 100-year flood barrier height that will help protect people, homes and businesses in Sunnyside/Hillhurst from river flooding.

Benefits of the 1 in 100-year flood level barrier height

  • Reduces the 2013-level flood risk, which will be further reduced by current and future upstream reservoirs on the Bow River.
  • Less disruptive to the community look and feel
  • Increases the ability to protect vulnerable populations
  • Meets the provincial and federal flood standard (1 in 100-year)
  • Provides the building blocks for future climate resiliency

Addressing other sources of flooding in Sunnyside

Due in part to the geography as well as an outdated drainage system, Sunnyside is more prone to flooding and this is something that The City is working to fix. In addition to the flood barrier, several projects have been completed or are currently underway to reduce flooding that happens in the community.

Visit for a list of projects and up to date information.

Is the location of the flood barrier finalized?

The location of the flood wall is not yet finalized; the location will be refined as the design progresses. The general alignment of the flood barrier has been determined. We are currently in the detailed design stage, which takes a closer look at the constraints and refines the design  such as the exact location and type of flood barrier over the 1.9 km length.

Why is the Sunnyside flood Barrier a 1 in 100-year barrier?

The 1 in 100-year option is the recommended barrier height for Sunnyside because it’s reflective of the best balance between social, environmental and economic considerations. It’s an investment that enhances the safety of residents and our ability to protect those most vulnerable, while having a lesser impact to the community look and feel. The 1 in 100-year option meets the federal and provincial flood protection standards. When constructed, it will immediately reduce Sunnyside’s risk from a 2013-level flood. This option will be further enhanced by current and future upstream reservoirs on the Bow River, allowing it to manage even larger floods.

How will the Engagement for the Memorial Parkway be used for the Sunnyside Flood Barrier project?

Feedback garnered through public engagement will be used to inform elements such as public amenities and open space adjacent to the flood barrier and will not inform any design decisions for the flood barrier. We do not anticipate that engagement for the Memorial Parkway project will delay the overall construction timelines for the Sunnyside Flood Barrier project.

How is The City coordinating with other projects in the area?

As we advanced the flood barrier design, we recognized the significant impact this project would have on the area. During this time, it also uncovered some opportunities to integrate the flood barrier into other work that was happening in this area and a desire to capitalize on this moment to protect and enhance the area as much as possible while adding the flood protection. 

To help increase flood resiliency and create spaces that enhance the connection with the river, natural environment and commemorate our heritage, we’re combining this work through an integrated program. We recognized that by taking a more integrated approach we could achieve the best outcome for the area.

What flood protection is provided to Sunnyside residents in the meantime?

As part of The City’s emergency response plan, we are ready to respond, if needed, in areas that are still vulnerable to river flooding. We stockpile riverbank protection and temporary barrier materials and each spring our City teams review their plans, conduct site visits and train crews.  

In addition, every spring, infrastructure such as water main valves, stormwater outfall gates, lift stations and pump are prepared, tested or positioned for flood season to reduce potential damages during a flood.

Why is a Construction Management approach being used for the project?

PCL Construction Management Inc. (PCL) has been selected as the construction manager for delivery of the Sunnyside Flood Barrier project and public realm improvements.

We are using a construction management approach to allow the project team greater design flexibility and project control to address schedule and community impacts.

We know that there are several historical and socially significant sections of the Sunnyside Flood Barrier alignment, so using a construction management approach allows more time to work through the details of those while getting started on the more straightforward areas.

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