The Southern Alberta Fisheries Habitat Enhancement and Sustainability (FISHES) Program was developed to mitigate the risks to aquatic environments caused by extensive fording and off-roading following the 2013 floods. FISHES proposed the installation of a strategically placed bridge over Waiparous Creek to replace several fords that were being used in the creek. Alberta Environment and Parks (AEP) retained ISL to design a single lane, clearspan
bridge and approaches to provide permanent crossing over Waiparous Creek. ISL investigated several bridge options; completed preliminary and detailed structural design; conducted a fish habitat assessment, environmental assessment and flood level analysis; and provided permitting, tendering, cost estimates and construction services.
Since the crossing is in a Critical Habitat for Westslope Cutthroat Trout – a threatened species according to the Species at Risk Act (SARA), the team had to be extra cautious to ensure fish were not impacted. ISL engaged Fisheries and Oceans Canada to determine if a SARA permit was required and designed the work to ensure that there would not be an instream footprint. ISL also recommended the use of rig-matting to develop a temporary crossing with limited impact to the creek.
Waiparous Creek Bridge was the first bridge constructed by AEP following the merger with Parks and the first major project under the FISHES program. The structure had to withstand 100 year floods, carry a 15 Tonne vehicle, be virtually maintenance free and resilient to shotgun blasts. ISL used a modular structural design that was built with minimal equipment on-site and prefabricated in place without temporary supports. The result was a steel plate girder bridge with a precast concrete deck and galvanized steel railings, supported on a concrete abutment with micropiles. Rip rap was used for scour protection.