Calgary improves its flood defences with steel sheet pile

Canada is experiencing a significant increase in the frequency and intensity of flooding events. "Increasingly frequent and intense short-duration heavy rainfall events increase the likelihood of flash floods, especially in urban areas, as these rainfalls can overwhelm storm drains and drainage systems."

As a result, densely populated coastal and riverine areas across the country are reassessing their flood preparedness measures, with Calgary being particularly focused on the flood threat.

To avoid a repeat of the 2013 floods (which caused one death and $6 billion in property and economic damage), the city of Calgary, Alberta, is building a 2.4-kilometer-long flood barrier.

This barrier, named the "Sunnyside Flood Barrier," consists of permanent flood walls and temporary, deployable systems such as sandbags, water-filled pipes, and removable flood walls.

Sheet pile flood walls are best suited for densely populated built-up areas.

Sheet pile flood walls comprise approximately half the length of the flood barrier. This is because sheet piles are particularly suitable for confined spaces and require minimal demolition of surrounding buildings or trees. These permanent, interlocking sheet pile walls are designed to block floods and are buried three to six meters underground to ensure structural stability.

Ground vibrations generated during sheet pile installation could damage nearby utilities, bridges, or housing infrastructure. To avoid this, vibration monitoring is continuously conducted throughout the installation process.

Because sheet piles impede groundwater from the community's aquifer into rivers, they cannot be used for the entire flood barrier. For areas where free flow of groundwater is required, concrete flood walls are constructed, as they meet this requirement.

The flood barrier is expected to be completed in the spring of 2026.

Sheet piles are used to enhance flood protection.