Fulton Ditch Irrigation Efficiency Project Phase 1

The Fulton Ditch Irrigation Efficiency Project (Phase I) is a restoration project that enhances instream flow in the lower Chewuch River and Middle Methow River. Trout Unlimited will use these funds to develop an ecologically beneficial alternative and preliminary design for the Fulton Ditch system.  The Fulton Ditch diverts water from the Chewuch river for irrigation and other water uses, the ditch is an open earthen ditch and much of the diverted flow is lost to conveyance and seepage before it is put towards the intended uses. Spring chinook salmon and steelhead in the Chewuch and Methow Rivers are both limited by low summer flows and high water temperatures. This project is the first phase in developing an efficient irrigation system that meets the needs of the Fulton Ditch water users while also reducing the quantity of water diverted from the Chewuch, enhancing instream flow and reducing high water temperatures that limit salmon, steelhead and other aquatic life in these rivers. 

This project promotes chinook, steelhead and other cold water fish productivity and abundance by improving habitat conditions through instream flow restoration. Upon completion of this project streamflow in the Chewuch will be enhanced to meet or nearly meet target flow goals on normal water years and reduce low flow impacts during drought years. Water saved through system efficiency would restore and legally protect an estimated 5-15 cfs of water in the lower Chewuch and middle Methow that is currently diverted by the Fulton Ditch for irrigation. Fulton water in the 8 miles above the point of diversion is legally and permanently protected from future changes and left instream. This increased flow represents 6 - 19% and 2 - 6% of the September mean monthly discharge in the lower Chewuch and middle Methow, respectively. Water temperature and streamflow are inversely related. By restoring flow during irrigation season, summer water temperatures will be reduced providing holding and rearing habitat for adult and juvenile fish; and higher flows in the lower Chewuch and middle Methow will provide better adult fish passage and spawning areas. This project is a part of basin wide efforts to restore streamflow and cumulative efforts throughout the basin are necessary to achieve measurable flow goals in these larger systems. Further, 5-15 cfs in the Methow may not be measurable with current methods but could be the difference between a side channel or cold water remaining engaged.