Pine Hollow Reservoir Project

The Pine Hollow Reservoir Project is a proposed off-stream reservoir. The main purpose of the reservoir will be to: restore in-stream flows for fish and aquatic wildlife; improve and stabilize riparian habitat for wildlife; attenuate flood flows; provide irrigation water to the Ahtanum Irrigation District; and to provide irrigation water to Yakama Nation through the Wapato Irrigation Project. Excess water will be diverted to the reservoir during high runoff conditions during snowmelt, and the water will be used to restore flow year-round. Due to heavy demand for irrigation water, the main branch of the stream is dry nearly every summer from July through October. The annual dry period causes: a reduction of fish habitat for trout and salmon: blockage of fish passage to upper watershed spawning areas: destruction of stranded aquatic life due to a dry stream bed; gradual groundwater depletion through supplemental use of irrigation wells: increased energy use form pumping groundwater; deterioration of wildlife habitat; increase erosion of soils; and depletion of shallow groundwater due to reduction of recharge. The Pine Hollow Reservoir Project is planned to mitigate these problems. 10 pp.