WENATCHEE, Wash. — The crack in the Wanapum Dam may have been there for some time.

The director of hydro operations for the Grant County Public Utility District told The Wenatchee World editorial board part of the 2-inch wide crack had algae growing inside. But Dawn Woodward said other parts of the 65-foot wide crack were clean, indicating more recent.

The crack was discovered Feb. 27, and the utility lowered the reservoir to reduce pressure on the dam until it can be repaired. That has affected power production, irrigation and the fish ladder. Authorities have closed the exposed shoreline to the public.

A contractor is drilling to map the size of the crack so authorities can develop a repair plan. They could decide to drill anchors through the dam into the bedrock.