Share this page Print

Bowness Flood Barrier

What's happening

Bowmont Park

The proposed Bowness flood barrier is a foundational piece of The City of Calgary's Flood Mitigation and Resiliency Plan. In conjunction with upstream storage, provided by construction of a new reservoir, and modified operations of TransAlta's Ghost reservoir, it will help us better manage flood water and avoid the type of damage we saw in 2013.

Work on the proposed Bowness flood barrier is in the preliminary design stage, which takes place from fall 2018 to Q1 2020. It consists of gathering feedback from community members, conducting site surveys, and completing engineering studies and analyses.

Upcoming studies and analyses

Beginning in fall 2018 and continuing into 2019, the following studies and analyses will be undertaken:

  • Hydrogeological (groundwater studies) - currently underway
    • The City has installed monitoring wells on public and private land to understand the ground conditions and potential impact from groundwater flooding to the community. The monitoring wells will be in place until summer 2020. See map of monitoring well locations.
  • Geotechnical investigations - currently underway
  • Flood modelling
  • Stormwater management
  • Landscape architecture and design
  • Biophysical impact assessment - currently underway
  • Revised cost estimates and Triple Bottom Line

Getting input from the Bowness community

Engagement with the broader Bowness community began in early 2018. Engagement with riverfront property residents began in fall 2018 and will be an important piece of the preliminary design process.

Much of the riverfront property is privately owned in Bowness. Throughout the preliminary design phase, the project team will be working with individual property owners to gather their input, discuss their concerns and develop ideas to be potentially incorporated into the finalized preliminary design options.

The project team has been meeting one-on-one with riverfront property owners to better understand the unique characteristics of their property and discuss ideas on how to best integrate the barrier into the existing landscape, while protecting the community. From here, the design team will use a combination of aerial photos, resident input, along with information collected through technical studies to develop design options.

Design options are tentatively scheduled to be ready in fall 2019 for review and will be presented to riverfront property residents at that time.


Background

1615

Bowness Flood Barrier

Edit accordion

The City often refers to temporary and permanent flood barriers. A wall constructed of sandbags is an example of a temporary barrier. An earthen berm is an example of a permanent barrier. Whether temporary or permanent, flood barriers are constructed to keep floodwaters from entering a certain space – it could be a home, infrastructure, a roadway, etc.

As part of The City’s overall flood mitigation strategy, the construction of permanent flood barriers in several riverfront communities, including Bowness, has been proposed.  

Right now, the types of barriers being proposed are a combination of earthen berms and concrete floodwalls, however the detailed designs will be developed, working with riverfront property owners.

Edit accordion

Homes, buildings and other infrastructure in Bowness are impacted when river flows reach levels of 850 cubic metres per second (m3/s).

Without any flood mitigation in place, there is a 12 per cent chance in any given year that Bowness will experience overland flooding. Mitigation infrastructure like reservoirs and barriers help reduce flood risk. When you factor in the TransAlta agreement for the Ghost Reservoir that was put in place in 2016, the annual flood risk in Bowness reduces from 12 per cent to five per cent.

What’s important to remember is that Mother Nature doesn’t always follow our scientific calculations and through climate modelling we know that Calgary will experience more severe and frequent extreme weather events such as flooding. So, it’s not a matter of if, it’s a matter of when. That’s why it’s so important that we take action and put in the necessary steps to make communities, like Bowness, more resilient before the next flood happens.

While the current modified operation of the Ghost Reservoir is an effective means of helping to reduce Calgary’s flood risk, it is not enough on its own. Ultimately, to help reduce the risk of another 2013-level flood, the best approach is to use a combination of permanent and reliable solutions including an extended agreement with TransAlta, a new upstream reservoir and complementary barriers.

Edit accordion

In 2016, The City hired external consultants to update the Provincial Flood Damage Assessment study for Calgary, and to assess and recommend future resiliency and mitigation measures.

The resulting document, the Flood Mitigation Measures Assessment (FMMA) report, was approved by Council in spring of 2017. Recommendations include the following combination of mitigation solutions to create a flexible and adaptable flood risk management program.

  • Watershed-level mitigation:
    • Modified operations at Ghost Reservoir as part of the current five-year agreement between the Government of Alberta and TransAlta.
    • Construction of an upstream reservoir on the Bow River.
  • Community level mitigation
    • The City is proposing building permanent flood barriers that will extend from the CP rail tracks to the Shouldice Bridge.
    • Height of the barriers will vary depending on the location.
  • Property level and policy mitigation
    • Policies, bylaws, land use regulations, building codes, incentive programs for flood proofing and public education.

There isn’t one single project that will provide adequate flood protection on its own on the Bow River. Each piece of the strategy provides great benefits independently, but together, they ensure the most effective flood protection strategy.

Location

The City is proposing building permanent flood barriers that will extend from the CP Rail tracks to the Shouldice Bridge.

The City is proposing building permanent flood barriers that will extend from the CP Rail tracks to the Shouldice Bridge. Approximately 130 riverfront properties fall within the proposed barrier alignment.

The map below highlights the area of land (purple and yellow area) that a permanent flood barrier would mitigate the flood risk for.

Christie Park Drainage Improvements
Click on image to enlarge

Edit accordion

With no flood mitigation measures in place, the riverbanks in Bowness can withstand river flows up to 850 m3/s without flooding.

To protect the Bowness community from a flood event similar to 2013, the Flood Mitigation Measures Assessment showed that a combined approach of a new upstream reservoir, modified TransAlta operations and complementary permanent flood barriers was the best approach.

Until a new reservoir is built on the Bow River, the permanent flood barriers will also provide the community with additional protection from smaller floods that are more likely to occur.

Bowness Flood Mitigation Chart
Click to view larger image.
Edit accordion

Project Team

The project team is comprised of a group of internal experts and external consultants. The external consultants hired to work on this project are:

  • Klohn Crippen Berger Ltd. - Engineering consultant
  • 02 Planning and Design Inc. – Landscape architects - Barrier design/integration into landscape
  • Context Research Inc. - Public engagement
  • Matrix Solutions Inc. - Stormwater studies

Project Budget

  • $25 million

A detailed project plan is in the process of being developed, but if the project proceeds, it’s anticipated that it will be funded 70/30 between the Province and The City, respectively.

The City is also actively working to determine federal funding opportunities to support any flood mitigation work, which would have similar cost share obligations for The City.

Edit accordion

Bowness Flood Barrier Project Time
Click to view larger image.

Public Engagement

Community survey - May 21 - June 10
Purpose:

We are conducting research in Bowness to better understand the community's level of awareness and perspectives on flood mitigation. The results will be used to identify areas where residents are looking for more information to better understand the proposed plans and the flood protection benefits.

Two separate surveys will be conducted including an online survey with riverfront property owners and a telephone survey with randomly selected residents from the broader Bowness community.

Please note: Residents can only complete the telephone survey if their phone number is randomly selected by the research firm.


Wildlife study
Purpose:

In addition to the wildlife observations that independent biologists will be noting this year, if you have photos of wildlife in the Bowness area, please submit these pictures online and note their location on the project’s Engage page.


Site meetings with riverfront property owners - Spring 2019
Purpose:

The project team is meeting individually with riverfront property owners to discuss the project and collect information about each property to be used in developing a preliminary design for the proposed Bowness flood barrier. The project team will bring copies of the following questionnaire to the meeting. Residents do not need to print/fill out their own copy.


If you are a riverfront resident and would like to sign up for a one-on-one, please contact Lauren Minuk at 403-268-8044 or email bownessbarrier@calgary.ca
 

View previous engagement activities, reports back to the community and presentations


Stay connected


Project specific information




Videos