The Bureau of Reclamation's Yakima Field Office announced today that flows from Rimrock Reservoir into the Tieton River will begin increasing around June 1. Current flows from the dam are about 250 cubic-feet-per-second. As of June 1, the storage level at the reservoir was about 2,600 acre-feet below the active capacity storage level of 198,000 acre-feet.
Between June 1 and June 4, Rimrock Reservoir is expected to approach the active capacity storage level and then flows into the lake will pass over the spillway and through the regulating gates. The current inflow rate of spring runoff into the reservoir is approximately 900 cubic feet per second. Once the reservoir is full, flows into the Tieton River may range between 200 and 1000 cubic feet per second or higher during the spring runoff period.
Tieton Dam and Rimrock Reservoir are part of Reclamation’s Yakima Project and is located about 40 miles west of Yakima, Washington. The 319-foot high structure was built in 1925.
Source: Bureau of Reclamation
