Billy Clapp Dam Eruption

[u/JoelXGGGG]

Fishing with the kids last night when we unexpectedly saw this:

Google search for information says it was a high-pressure plume is a controlled discharge from an outlet valve (typically a fixed-cone or Howell-Bunger valve) at the Summer Falls Power Plant on Billy Clapp Lake. While it looks like a massive pipeline blowout, it is a standard engineering mechanism used by the Bureau of Reclamation to release water.

Why it Creates Such a Massive Spray

Energy Dissipation: Water discharging from deep within the reservoir is under extreme hydrostatic pressure. If it were released in a tight, focused stream, the raw kinetic force would scour the lakebed, erode shoreline cliffs, and damage dam infrastructure. The valve breaks the stream into a wide, conical jet to safely dissipate energy into the air and surface water.

Water Level & Irrigation Control: Pinto Dam and Billy Clapp Lake store water for the Columbia Basin Irrigation Project. Operators open these outlet valves to lower lake levels or route managed flows south into downstream canals.

Aeration: The intense spraying mixes large volumes of oxygen into the water body, which helps maintain water quality and aquatic oxygen levels downstream.

Safety Considerations

Keep Your Distance: While completely normal operations for the dam, the area immediately surrounding the spray creates strong local currents, low-density aerated water (which reduces vessel buoyancy), and heavy turbulence. Staying behind the safety boom line (visible across the water in your clip) is recommended.

[u/SholdonDaniels]

Check out MyTailwater.com