A Wanapum Dam crack measuring 65 feet in length and two feet in width was discovered by divers prompting emergency procedures. The Wanapum Dam, which is a hydroelectric project located on the Columbia River in Grant County, Wash., is still in operation, reports ABC News on March 1, 2014, but due to the severity of the problem, “a crisis scenario plan has been implemented.”
The dam, which was built in 1959 and is more than a mile long, can generate more than 1,000 megawatts of power. The 65-foot crack was discovered along the base of one of the dam’s spillway piers.
Implementing a crisis scenario plan means that the damage is sufficiently significant, and that there is a danger that the dam could fail.
The Wanapum Dam crack was first noticed by an engineer who saw that the roadway above the dam was “bowing.” Upon further examination, it was discovered that the concrete spillway was actually raised above the water by 2.5 inches, prompting divers to investigate the cause under water.
In addition to the diving expedition to verify the extend of the damage (which at this time seems to be limited to only one of the dozen concrete spillway sections), engineers are working on stabilizing the dam.
Wanapum Dam emergency procedures that have been initiated so far include notifying residents who own land below the dam and lowering the dam’s water elevation by 20 feet. “The failure of the dam would primarily affect the town of Vantage, which is six miles upstream.” No evacuations have been issued at this time.
Wanapum Dam update:
According to an updated report by NWPR on March 2, Thomas Stredwick, spokesman for the Grant County Public Utility District, commented that at this time “the lower pool is affecting power production, but homeowners won’t be affected. The worst-case scenario is if the spillway was to topple.” Dam operators expect that other sections of the dam should hold and that downstream communities should be safe. “Columbia River dam operators plan for events like this crack, but hope they never occur.”