Local News

Dam inspection requires red dye test at Salmon Lake Dam

Apr 23, 2020

To enhance monitoring efforts at Salmon Lake Dam, the Bureau of Reclamation announced today they will conduct a seepage analysis using a water-safe red dye on Thursday, April 23, 2020, to assess a small, vertical hole discovered at the dam. The analysis will be used to help determine an appropriate solution for filling the hole.

Reclamation will use, Rhodamine, a water tracer approved by the Food and Drug Administration and the Environmental Protection Agency, and it will be measured in very low levels of concentrations (parts per billion or less). To conduct the dam inspection, water in the stilling basin will be pumped out, requiring operation of diesel engine generators early Thursday morning and possibly into Friday morning. A mix of the dye and water will be poured into the hole, which will help to determine the path the water is taking and how quickly the water is flowing. Together, this information will help inform a resolution to the issue at the dam.

“Area residents may observe the water downstream of the dam temporarily stained red or pink, during and after the tracer test, until the dye is sufficiently diluted,” said Ephrata Field Office Manager Marc Maynard. “The dye is not harmful to people or the environment.”

“Conditions at the site are stable and there is no risk of failure at the dam,” said Maynard. “Reclamation, who owns the dam, and the Okanogan Irrigation District, who operates and maintains the dam, will continue to communicate current status with county officials as we walk through the next steps of this process.”

Salmon Lake Dam, part of the Okanogan Project, is an earthen dam constructed between 1919 and 1921 and is authorized by Congress to manage water for irrigation and flood control. The dam measures 54 feet high and 1260 feet long at its crest.