Each year, tens of  thousands of people visit waterways and parks near Idaho Power dams. We think the more you know about dams, the safer you'll be. Let's look at the basic parts of most hydroelectric dams.

First there's the reservoir, the impounded water behind the dam (A). To generate electricity, water from the reservoir is released into a massive pipe called a penstock (B), where it enters the powerhouse (D) deep within the dam. The force of this water striking the turbine causes it to rotate. The turbine is connected to the generator that also turns to produce electricity.

All of the water that goes into the turbine then drops into a draft tube and returns to the river downstream of the dam in what is called the tailrace (E). Sometimes more water is available than the turbines can use. When that happens large volumes of water are released through the dam's spillgates over the spillway (C).

Each of these areas, particularly the inlets for the penstock and the tailrace, can be dangerous.

Keeping Safe In The Water
Normal power plant operations can cause unexpected and rapid water level fluctuations. Don't wade, swim, fish or anchor your boat directly upstream from a dam or spillway. Stay well upstream of the dam's line of warning buoys. If for some reason water had to be released through the spillgates, you could be swept over the dam's spillway.

Water that flows into the dam's penstocks can create strong, unseen currents that could pull you underwater. Play it safe. Stay out of the water directly upstream of a dam and spillway, and keep off the banks next to the spillway, too.

If your boat's anchored immediately downstream of a dam near a spillway, it could be swamped by a sudden water release. Also keep away from the dam's tailrace. The water in this area could be calm if a generator is not working but may become turbulent  if the generator suddenly comes back on-line.

Learn more about Precautions You Can Take.