It would cost the city $73 million to reduce the flood risk at 27 underpasses or inner-ring transportation corridors, according to a new report released Monday.
Thirteen locations, including eight with known flood histories, have been identified as the highest risks, the report said.
Included in that list are five underpasses along Whitemud Drive, including at 106th Street, where 10 people were rescued by boats following a downpour in July 2016.
Eight underpasses have flooded since 2004 when rainfall exceeded design standards, the report said.
Thirteen locations, including eight with known flood history, have been identified to be at the highest risk of flooding. (City of Edmonton)
Several solutions are outlined in the report, including:
- catch-basin improvements to increase the amount of surface water that can drain into the sewer system;
- construction of new sewers to carry water away from problematic areas;
- underground storage to hold runoff until it can be carried away by the sewer system;
- gates and real-time control systems that can manage water flow, balancing pipe capacity throughout the entire system to prevent flooding
Improvements to high-risk locations would cost $19 million, and improvements to medium-risk locations would add another $54 million, the report said.
The capital costs can be included in the city-wide flood mitigation strategy and reported back early in 2018, with a recommended implementation plan, the report said.