Klohn Crippen Berger Ltd. (KCB) undertook the detailed design of the Outfall B134 repairs and river bank stabilization project, as part of the City of Calgary Stormwater Outfall Upgrades project. The works involved placing riprap to protect a 100 m section of the Bow River bank adjacent to the Valley Ridge Golf Course and reattaching a separated outfall.

The design incorporated a riprap toe that was keyed into the gravel river bed so that it would have minimal impact on fish habitat and river craft. In addition, willow pole plantings were incorporated in the riprap to improve fish habitat and help stabilize the revetment.

Through early consultation with the regulatory agencies, KCB secured all approvals in time to undertake the works during the April 2012 in-stream construction window. KCB provided support throughout construction, providing regular updates to the Valley Ridge Golf Course and the City. The in-stream works were isolated from the Bow River using a turbidity curtain and the construction schedule focused on completing the in-stream works outside of the restricted activity period.

There was severe flooding of the Valley Ridge Golf Course during the June 2013 flood, but there was negligible damage to the erosion protection works and outfall repairs. The riprap was stable and the willow poles were flourishing post flood.

Services

• Preliminary design
• Detailed design of river bank stabilization works and outfall repairs
• Regulatory Agency Approvals (ESRD, DFO, and Transport Canada)
• Fish and Fish Habitat Assessment
• Preparation of tender documents and tender support
• Construction support
• Post June 2013 flood inspection