Water Safety

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. To generate electricity, water from the reservoir is released into a massive pipe called a penstock, where it enters the powerhouse 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 the tailrace. Sometimes more water is available than the turbines can use. When that happens, the spillway releases large volumes of water through the dam’s spillgates.

illustration of a dam and the various parts are marked with letters corresponding to the list below.
  • A – Reservoir
  • B – Penstocks
  • C – Spillway
  • D – Powerhouse
  • E – Tailrace

Each of these areas can be dangerous, especially the inlets for the penstocks and the tailrace. Be safe in the water by knowing these boating safety guidelines.

Keep 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.

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. Keep off of the banks next to the spillway, too.

If your boat is anchored immediately downstream of a dam near a spillway, it could be swamped by a sudden water release.

Keep away from the dam’s tailrace, too. 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.

Safety Precautions

  • Keep alert when downstream of a dam. Be prepared to leave the water quickly.
  • If caught in rising water, stay calm and move diagonally across the current until you reach safety.
  • If trapped on an island that’s not likely to become submerged, stay there and signal for help. Do not try to swim or wade across the river.
  • Look up for overhead power lines when raising a sailboat mast. Stay clear of any area beneath overhead power lines.
  • Check the local weather before launching your boat.
  • Watch for submerged objects. Don’t dive, swim or wade without first checking for underwater hazards.
  • Wear a Coast Guard-approved personal flotation device or a life jacket when boating or using fishing waders.

Idaho Power Safety Measures

Most Idaho Power dams have sirens and strobe lights that signal when dam spillgates are about to be opened. If you hear or see one of these warning signals, immediately leave the area downstream of the dam or the spillway.

Buoy lines and cables with warning signs are there to keep boaters and swimmers at a safe distance from our dams. Don’t cross, tie up to or go under these lines. If for some reason water had to be released through the spillgates, you could be swept over the dam’s spillway.

Don’t climb over protective fences near spillways, dams and substations. They are there to keep you safe.