If you’re in the water near a dam, powerhouse or lock, you need to be aware of some potential hazards and familiarize yourself with the systems TVA uses to communicate them to you.
Wilson Dam – B.A.S.S. photo
A large amount of water can be released from a dam without any warning at any time and by any means. For example, when the demand for electricity is high, the turbines at a dam may be turned on automatically, resulting in a significant increase in the downstream flow of water in only a matter of seconds.
WARNING! Water release schedules often change without notice due to weather and power system requirements. Large amounts of water could be released at any time. Caution is needed. Your safety depends on obeying all posted safety regulations and precautions!
If there’s a need to release water through the sluiceways—outlets at the base of the dam—this operation, too, can create a great swell of discharged water downstream.
During flood operations, any or all spillway gates across the width of a dam can be opened to release upstream flood water that needs to pass to the next downstream reservoir. Upstream or downstream, even the most experienced boater with the strongest motor is no match for this strong flow of water plunging over a spillway of a dam. Even if you’re boating far downstream of a spilling dam, recirculating current can pull a powerful boat upstream toward plunging water that could shred any boat.
Some dams equipped with navigation locks create turbulent water as well. When vessels pass through, strong flow is released near the exhaust ports of the wing wall of the lock.
Warning Systems at Dams
To warn reservoir users of potential danger, TVA has installed the following warning devices:
Horns: Horns are sounded before water is released from the powerhouses, sluiceway or spillways. When you hear these horns, leave the areas upstream and downstream of the dam immediately.
Strobe Lights: Strobe lights are activated before the hydro plant begins generating electricity at the powerhouse or releases water through the spillway or sluiceway. When you see these strobe lights flash, leave the areas upstream and downstream of the dam immediately.
Warning Signs: Signs direct visitors to stay clear of hazardous areas and warn of rapidly rising water and sudden spillway and turbine water surges. Take them seriously—obey all warnings!
Electronic Spillway Signs with Strobe Lights and Horns: These warning devices are activated before the hydro plant begins generating electricity at the powerhouse and/or releases water through the spillway or sluiceway. When you see or hear these warnings, move away at once
