AltaGas
Iskut River, British Columbia
Hydroelectric Operations and Reservoir Sedimentation
AltaGas
Iskut River, British Columbia
Hydroelectric Operations and Reservoir Sedimentation
The 195 MW Forrest Kerr hydroelectric project is located on the sediment rich Iskut River. The facility consists of a diversion dam, intake structure, desanding facility, 3.2 km power tunnel, tailrace tunnel, and an underground powerhouse. During the design phase of the project, NHC developed a three-dimensional Computational Fluid Dynamics (CFD) model to predict the head losses and velocities for the intake structure, which led to relocation of the desander to eliminate uneven approach flow conditions and excessive sediment potentially entering the intake. A 1:40 scale physical model was also used to further evaluate and optimize the intake. Once the facility was constructed, NHC developed means of directly monitoring bed elevations that enable operations to determine when to sluice sediment. NHC also developed means of monitoring sediment deposition in the desander and sediment load out of the desander. These sensors were instrumental in having a pneumatic purge system added to the desander.