Exposed Shoreline at Wanapum Dam Closed to the Public
The Grant County Public Utility District says the shoreline exposed by the low water levels at the Wanapum Dam, are now closed to the public.
BEVERLY, WA - The Grant County Public Utility District says the shoreline exposed by the low water levels at the Wanapum Dam, are now closed to the public.
The PUD closed the shoreline on Wednesday, and is only allowing authorized personnel access below the high-water mark of the reservoir. The utility says it is posting signs and patrolling the shoreline. Grant PUD says it will notify state and local law enforcement agencies if anyone is seen trespassing on PUD lands.
The utility says sections of the shoreline, including the riverbank and mud flats are unstable, and pose a serious safety hazard. Along with the exposed shoreline areas, boat launches on the Wanapum and Priest Rapids dam reservoirs are also closed.
The Wanapum Dam Overlook however, which is operated by Grant PUD, remains open to the public.
The utility says it continues to work with experts and regulators to determine the best course of action to repair the fractured spillway monolith at the dam. On March 4th, Grant PUD lowered its Emergency Action Plan classification to a "non-failure emergency."
The downgrade came as a result of surveys engineers conducted earlier this week, that found one of the dam's spillways is now stable.
The damage was first discovered on Feb. 24 by a dam worker who noticed a section of the spillway deck that had shifted slightly upstream. Utility engineers then examined the area and found that one of the spillway pier monoliths had moved 2 inches out of alignment. Divers inspecting the spillway on Feb. 27 discovered a horizontal fracture about 2 inches wide at the base of the monolith.
To take pressure off the damaged spillway pier, the utility began to draw down the reservoir behind the dam by about 26 feet.
On March 4, survey results showed the impacted area was stable, the fracture had closed and the pier had shifted back into its normal position by 1.75 inches. The utility has continued to monitor the area and has found no further movement since March 4.
Grant PUD remains able to meet customer electricity needs with its current power-supply portfolio. The Wanapum Dam continues to generate about half of the electricity it would produce under normal river conditions.