10 Street S.W. Gravel bar

Over the past several decades, a gravel bar has been forming in the Bow River under the 10 Street SW Bridge, also known as Louise Bridge.

The 10 Street Bridge connects the communities of Kensington and Sunnyside to the west end of downtown Calgary. 

Project Update – August 2023

The project team is currently working on the preliminary design for the 10 Street Gravel Bar project. Please check back on this page for updates.

Project overview

Gravel bars form naturally in rivers from sediment movement. They become a concern when they form in and around bridges and constrict flow of the river.

  • The 2013 flood resulted in a dramatic increase in size of the gravel bar.
  • Since 2013, the gravel bar has become vegetated with plants. It is expected to continue growing in size, increasing flood risk to the area.

The growth and vegetation on the bar increase the flood risk to the surrounding area, by blocking water flow through the bridge and reducing its capacity.

  • This increases water levels upstream that can spill into the adjacent neighborhoods.
  • It also causes erosion along the opposite banks and bed of the river which can put infrastructure at risk, including bridges, outfalls and pathways.

The aerial images below show the gravel bar’s increase in size after the 2013 flood:

Aerial image of project area in 2012 (before flood)

Aerial image of project area in 2014 (after flood)

Realignment of gravel bar

To lower flood risk, the approach is to realign the gravel bar. This means that the gravel and soil would be removed and redistributed within the area of the river.

  • Realignment of the gravel bar would provide long-term flood mitigation benefits and be the most environmentally beneficial and stable solution.
  • By redistributing the removed materials, we can improve fish and riparian habitat in the area and naturalize the south bank.

Recreational wave

There is a natural wave adjacent to the gravel bar which has been used for recreation such as river surfing.

  • This wave has been decreasing as natural sediment movement continues to occur and the gravel bar increases in size.
  • The area is also hazardous for river rafters and floaters. They need to navigate around the gravel bar and can get stuck on the boulders where the river turns after the bridge.
  • Realigning the gravel bar would also result in safer navigation for river users.

The project team is exploring incorporating a permanent recreational wave as part of this project. We are working with Alberta River Surfing Association and the Alberta Whitewater Association who provide expertise and represent river recreation user groups. 

Next steps

We are currently in the preliminary design phase, with detailed design starting in Winter 2024. The construction schedule and impacts will be determined as we move further along in the design process. Please check back on this page for updates throughout the project.


  • Preliminary design – Spring to Fall 2023
  • Detailed design – Winter 2024
  • Construction – Schedule to be determined

Related information


The estimated cost for this project is $10 million.

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For more information or questions, please email the project team at 10stgravelbar@calgary.ca

This information has no legal status and cannot be used as an official interpretation of the various bylaws, codes and regulations currently in effect. The City of Calgary accepts no responsibility to persons relying solely on this information. Web pages are updated periodically. ​