PROJECT LOCATION: Central Valley, CA
PROJECT PARTNER: Trout Unlimited
START UP DATE: 2017
PROJECT TYPE: Irrigation Infrastructure Modernization
WRCs GENERATED: Yes
Deer Creek flows for 75 miles from the snowfields of Mount Lassen to its confluence with the Sacramento River. Its middle section flows through a rugged canyon in the foothills of the Sierra Nevada and has reliable cold, clear, year-round flows that provide excellent habitat for Central Valley Spring-run Chinook salmon, a federally endangered species. But the lowest 11 miles of the creek flow across the Central Valley floor, where low streamflow and resulting warm conditions in the late spring and early fall can prevent fish from reaching the upstream habitat. These conditions are exacerbated by two large irrigation diversions.
Deer Creek Irrigation District (DCID) delivers irrigation water to 1,200 acres of walnuts, almonds, prunes, grapes & irrigated pasture using a 100-year old, 14-mile open ditch. Converting the ditch network to a closed-pipe system will reduce diversion, dedicating the water to instream flow. A pilot project tested high production wells to replace surface diversion during critical months combined with seasonal aquifer storage of surface water during winter months.
Converting the ditch network to a closed pipe system can reduce existing diversion by about 9.9 cfs (19.6 acre-feet/day). Assuming 60% of this amount could be dedicated to instream flow – over a 180-day irrigation season (May-Oct) this would save 2,117 acre-feet/year.