Hydropower Initiative
Thousands of miles of rivers and streams in California are affected by hydropower projects. These rivers and streams are dammed, diverted, used for water conveyance, and used to absorb outflow from power plants.
Hydropower activities in California have a detrimental impact on native fish populations in the following ways:
- Dams for hydropower projects create an impassable physical barrier for fish. Chinook salmon, for example, must make it into the upper reaches of rivers and streams to spawn.
- Dams convert the dynamic riverine habitats behind them into stagnant reservoirs. This negatively impacts water quality.
- Dams prevent substrate like gravel from traveling down rivers and streams. Chinook Salmon, steelhead, and trout require specific sized gravel in which to lay their eggs.
- Water released from reservoirs behind dams is too warm making it unsuitable for the survival of adult fish, their eggs, fry, and smolt.
- In many projects, water is diverted several times as water moves downhill. As a result many rivers and streams only have a small percentage of their natural flow left in them because most of the water is moved in canals, tunnels or pipes. This negatively affects the water quality of rivers and streams.
Whenever possible, CSPA works with resource agencies as colleagues. As a last resort, CSPA files lawsuits against resource agencies, project operators, and the Federal Energy Regulatory Commission (FERC).
Key Facts About How Hydropower Projects Function
In High Elevations
- Water from a stream or a reservoir is diverted into a canal, tunnel and/or a pipe that drops in elevation to develop pressure. The technical term for this pressure is “head”.
- The water then enters a penstock, a large pipe that drops down to a powerhouse.
- At the bottom of the penstock, the water passes through a turbine. The force of the water turns the turbine, thus generating electricity.
- The water is then discharged, sometimes directly into a stream or river, but more commonly into a reservoir often called an afterbay.
In Low Elevations
- Tall dams called rim dams are built to back up enough water so that pressure is created by the height of the dam itself.
- A powerhouse is usually located at or near the base of a dam, or even inside a dam itself.
Hydropower Campaigns
Recent News
Hydropower Initiative