The Campbell River’s waterflow was interrupted for about 13 minutes Sunday night, resulting in about about 30 salmon fry dying, BC Hydro reported this afternoon
BC Hydro has a standing commitment with the Campbell River community to advise of any unplanned river flow reductions in the Campbell River that go below 80 cubic metres per second (m3/s) and for more than 10 minutes. The river bottom is fully covered with water at 80 m3/s. Such an event took place on Sunday near midnight, BC Hydro spokesperson Stephen Watson said.
BC Hydro was operating the John Hart generating station at about 60 per cent of capacity, given the water abundance in the upper watershed reservoirs. The Campbell River flow has been at about 80-85 cubic metres per second for some time and this flow rate keeps key fish habitat below the generating station covered with water.
BC Hydro operates all available generating units at John Hart, six at this time, as contingency to allow for greater flexibility in recovering flows should an event like this take place to protect fish habitat. The idea being they can quickly ramp up the remaining operating units to recover from a flow disturbance.
At about 11:40 p.m. on Sunday, Generator #6 was forced off-line due to a pressure imbalance. The remaining five units were quickly ramped up to recover flows. However, this operational adjustment took time from the moment Generator #6 went out of service to when the flows were fully recovered to above 80 m3/s.
“We estimate the Campbell River flow dropped from about 82.5 m3/s to about 74.5 m3/s,” Watson said. “The flow was below 80 m3/s for about 13 minutes. The river flow was fully recovered to about 82 m3/s within about 15 minutes.” Government fish agencies were notified. Given the site conditions were wet with rain and the poor visibility, and that the flow recovery was quick, biologists were dispatched first thing this morning to key sites in the upper river. The risk from this event was to fry that tend to hang out at the edges of the river. About 30 chum fry mortalities were observed.
“Given the flow recovery time period and that river flow fluctuations attenuate downstream, we believe there to be minimal impacts to the fish population,” Watson said.
The John Hart Generating Station Replacement Project is building a water bypass facility within the new underground powerhouse so that if one or more units are forced offline, the bypass facility will automatically be initiated to re-direct the water and maintain downstream river flow continuity. Maintaining downstream river flows for fish is one of the three reasons for the project. The new facility is on schedule to be commissioned in fall 2018.