According to the Department of Fisheries and Oceans DFO, records, there are at present 33 existing dams and diversions built and operated by B.C. Hydro in the province. These are as follows. In the Columbia Region: Mica Project, Revelstoke Project, Keenleyside Project, Seven Mile Project, Walter Hardman Project, Whatshan Project, Spillimacheen Project, Aberfeldie Project, Elko Project, Duncan Project, Kootenay Canal Project.
Northern B.C.: WAC Bennett Dam and GM Shrum Generating Stations, Peace Canyon Project, Falls River Project, Clayton Falls Project.
Fraser River and Lower Mainland: Shuswap Falls Project, LaJoie Project, Bridge River Project, Seton Project, Wahleach Project, Stave Falls Project, Ruskin Project, Coquitlam Project, Buntzen Project, Alouette Project, Cheakamus Project, Clowhom Project.
Vancouver Island: Strathcona Project, Ladore Project, John Hart Project, Puntledge Project, Ash River Project, Jordan River Project.
The potential effects of flow control on fish and fish habitat include effects on productivity and water quality in reservoirs and effects on habitat quantity and quality, benthic productivity, water quality and fish behaviour downstream of release facilities. A list of the potential impacts of hydro dams and diversions on salmon is given below.
Physical Change
Upstream
Drawdown -reduced littoral productivity -reduced littoral spawning success -reduced tributary access -reduced water quality
Impoundment -reduced dissolved oxygen -settling of suspended sediment
Downstream
Reduced flow -reduced habitat quantity -altered water temperature
Inadequate flushing flow -accumulation of fine sediments in gravel substrate -changes in stream morphology
Increased flows -scouring of substrates -physical displacement of fish -destabilization of stream banks
Rapid flow fluctuation -displacement and stranding of fish and exposure of eggs
Flow diversion -disruption of fish homing to natal streams
Altered temperature -altered habitat quality regime -altered benthic productivity
Altered water quality -altered benthic productivity
Elevated total gas -injury or death of fish due to gaspressure bubble disease
The majority of B.C. Hydro projects were undertaken many years ago. At that time, potential impacts of facility operations on fish and fish habitat at a specific site were often not fully known owing to limited knowledge of the fisheries resources at risk at that site. Furthermore, in today's context, fish and fish habitat are often impacted by B.C. Hydro's management of its day to day operations. For example, flow constraints imposed at one plant for fisheries protection may have a system-wide effect, for example, block loading at one plant may increase load fluctuations at another plant, or result in even greater impacts at another facility. This is why it is important for DFO to work with B.C. Hydro to attempt to maximize benefits to fisheries from hydro operations.
In June 1993, the B.C. government directed B.C. Hydro to undertake a review to determine the feasibility of altering its electric generation system, operations to increase net social and environmental benefits to the province. The provincial government liaison committee, responsible for implementing the recommendations stemming from this review, established a fish power issue management committee on which DFO has representation. This committee in turn has established a technical working group which is reviewing B.C. Hydro water licences for facilities located on 10 priority watersheds in coastal and southern interior B.C., all of which support salmon. All 88 B.C. Hydro water licences will be reviewed within the next 3 years.
Through its participation on these committees and working groups, DFO is working to have fisheries protection measures incorporated into B.C. Hydro water licences. An example of recent fisheries/hydro interactions was the resolution of the low flow issue on Alouette River. Stakeholder negotiations involving federal and provincial agencies, First Nations, B.C. Hydro and public advisory groups resulted in a flow agreement based on scientifically defensible information and a socioeconomic model.
Despite such co-operative work, fish-power conflicts continue to arise in B.C. DFO will continue to work with B.C. Hydro to minimize these events but will nevertheless take action where appropriate, as is evident with the current Fisheries Act prosecutions for events occurring on the Bridge River in 1992 and 1993.