The foundations of four AltaLink transmission structures were threatened due to significant bank erosion along a 900m reach of the Oldman River, Alberta. Further bank erosion could impact the reliability of the line or require the relocation of the structures to another location.
Matrix Solutions provided hydrotechnical engineering and regulatory approval support, including:
- Hydrological, hydraulic, geomorphologic, fish habitat and wildlife assessments
- Detailed bank erosion protection and fish habitat compensation designs
- Provincial and federal regulatory approvals
- Engineering and environmental criteria monitoring during construction
- In-kind and complimentary fish habitat offsetting plans
- Critical Lake Sturgeon habitat identification in partnership with the Department of Fisheries and Oceans and Alberta Environment and Parks
- Critical timing constraints – spring freshet and restricted instream activity period to protect sensitive life-stages of local aquatic life
- The banks along the affected reach of the Oldman River were nearly 5m vertical due to continual erosion and sluffing, which made river access for construction challenging
Matrix successfully obtained all necessary regulatory approvals in just over four months. The river bank was successfully stabilized ahead of spring run-off to protect critical electrical utility infrastructure without any safety or environmental incidents. Bank erosion protection and fish habitat offsetting monitoring is ongoing until 2018.