City of Calgary update on riverbank stabilization and critical erosion sites
October 29, 2013, CALGARY, ALBERTA – Approximately 100 impacted riverbank erosion sites damaged by the June 2013 flood, have been assessed and prioritized by The City of Calgary, Water Services, with six sites categorized as critical. These sites are vulnerable to further erosion during high river flows and could cause damage to City infrastructure if no stabilization is implemented.
The six critical riverbank sites are located at 8 Avenue at 22 St. S.E. in Inglewood, Home Road and 52 St. N.W., Memorial Drive at 3 Street N.W., Diamond Cove S.E., ENMAX power station in Douglasdale and Memorial Drive at 19 Street N.W . Work has begun for the first two sites respectively, with Memorial Drive at 3 Street N.W. starting within the next two weeks. The remaining three sites are under study and design. The City’s intention is to have all critical sites addressed before the 2014 flood season.
According to Frank Frigo, Senior Planning Engineer, Water Services, “Prioritization of the sites is based on The City’s triple bottom line policy which accounts for economic, social, and environmental costs and benefits for each project.”
Factors range from vulnerability of the infrastructure to further damage, safety improvements realized by the repair work, impact on fish and wildlife habitat, and cost of capital repair work as examples.
“Bank restoration design and delivery is very complex and requires consideration of a number of elements,” adds Frigo. “The City is working closely with both the provincial and federal governments to ensure river navigation, public lands and environmental regulations are addressed as well as flood inundation and infrastructure protection. The location of all the sites poses further challenges and therefore requires thoughtful engineering and construction planning.”
During The City’s assessment work, 26 sites on the Bow and Elbow rivers were determined to have the potential of vulnerability in the next flood season. Plans are being developed to address them in 2014. Example locations include Lindsay Park and the pathway adjacent to Stampede. The remainder of the erosions sites are structurally stable and able to withstand another flood season.
“Damage to the riverbanks was extensive and there is a lot of work to be done,” says Frigo. “More than 35 km of riverbank was severely eroded along the Bow and Elbow rivers and it may be a number of years until we are able to complete all of the necessary work.”
When completed, cautions Frigo, the ntent of riverbank protection is to prevent further erosion and to protect critical infrastructure, not to reinstate the land lost to erosion. And where possible, we are using this opportunity to incorporate resiliency into the design to ensure enhanced bank stability that reflects today’s best practices and to avoid returning to the sites to do the work we can do now.”
Water Services is working closely with other business units like Parks and Roads to coordinate these projects as other City infrastructure was also damaged by the flood.
For more information on riverbank stabilization and erosion sites visit Calgary.ca/waterprojects.
- The City has assessed more than 30 km of damaged riverbank along the Bow River.
- The City has assessed more than 5 km of damaged riverbank along the Elbow River.
- More than 52,000 cm³ of rock is required for work on the three critical erosion sites currently underway - Home Road, Memorial Drive and Inglewood.