© 2026 Boise State Public Radio
NPR in Idaho
Play Live Radio
Next Up:
0:00
0:00
0:00 0:00
Available On Air Stations

Wanapum Dam Stabilizes With Drawdown, Engineers Say

Near rhe top of this image of Wanapum Dam, a slight bend is noticeable in the conduit below the guardrail. This is the anomaly spotted by a Grant PUD employee that resulted in discovery of the crack.
Grant County PUD
Near rhe top of this image of Wanapum Dam, a slight bend is noticeable in the conduit below the guardrail. This is the anomaly spotted by a Grant PUD employee that resulted in discovery of the crack.

As of Tuesday engineers say the Wanapum Dam’s major crack is stabilizing with the drawdown of the pool behind it.

The crack has decreased from two inches, down to about an inch. And it’s also shifted back into place a bit.

Dozens of engineers are working on Wanapum Dam’s underwater crack in the spillway portion of the structure. The most recent measurements show that the structure is righting a bit as the water level is lowered and pressure behind the dam is eased.

The dam continues to generate electricity, although at a lower level than usual for this time of year.

Because of the drawdown there is more exposed shoreline than has been seen since 1964. So now, state and local law enforcement are patrolling the newly exposed areas to deter archaeological looters or recreational vehicle damage.

Grant County owns and operates the dam under a federal license. Spokespeople say in a worst-case scenario, if one of the spillway sections failed, the remainder of the spillways and the main dam structure would remain intact.

Copyright 2021 Northwest News Network. To see more, visit Northwest News Network.

Anna King calls Richland, Washington home and loves unearthing great stories about people in the Northwest. She reports for the Northwest News Network from a studio at Washington State University, Triââ
Anna King
Anna King calls Richland, Washington home and loves unearthing great stories about people in the Northwest. She reports for the Northwest News Network from a studio at Washington State University, Tri-Cities. She covers the Mid-Columbia region, from nuclear reactors to Mexican rodeos.

You make stories like this possible.

The biggest portion of Boise State Public Radio's funding comes from readers like you who value fact-based journalism and trustworthy information.

Your donation today helps make our local reporting free for our entire community.