BC Hydro will be conducting river flow tests on June 21st and 23rd, 2011.
High water flow down Elk Falls Canyon on June 21 and 23
As part of our commitment to mind our footprint in the areas we operate, BC Hydro is continuing to carry out studies in preparation for the environmental assessment process for the John Hart Generating Station Replacement Project. An important element of our project studies and analysis is to initiate a river flow test down the Elk Falls Canyon.
On June 21, BC Hydro will be increasing the canyon water flow from John Hart Dam from the base flow of about 4 cubic metres per second (m3/s) to a maximum of 120 m3/s and bring the canyon flow back to 4 m3/s by the end of the day. On June 23, we will repeat the same river flow test process.
The controlled flow tests are required to better understand total gas pressure (TGP), fish presence, fish habitat at various flow levels, and canyon gravel movement thresholds. TGP is the opposite of the bends that people can get when diving. It occurs when too much air is forced into the water column where it may enter a fish‚Äôs body potentially leading to mortality. High water flow velocities can move gravel and impact fish habitat.
BC Hydro has a water license that allows for a maximum seasonal river flow. This means we will modify generating station discharge and water releases from the John Hart Spillway Dam so that appropriate water levels flow past First Island. At one point on both June 21 and June 23, there may be no water discharge from the generating station so that river flows downstream remain unchanged.
“Safety is our top priority so public river recreation from our property won’t be allowed during the tests due to potentially hazardous flow fluctuations, and people need to stay out of the upper Campbell River, particularly above Elk Falls,” says BC Hydro spokesperson, Stephen Watson. Public safety signage will be placed along the river to provide notice of the higher river flows at and above the generating station given the active recreation season.