Irrigation system work will reduce diversion, benefit fish
The Barkley Irrigation Company’s open ditch, which carries water for about 8 miles between Winthrop and Twisp, will be enclosed in a gravity-fed pipeline to reduce the amount of water diverted from the Methow River, eliminate stranding of fish in the ditch, and allow for future habitat restoration projects.
Planning for the Barkley project has been underway for more than five years, since federal fisheries officials warned the irrigation company that it needed to change the way it diverts water from the Methow River, said Aaron Penvose, a project manager for Trout Unlimited, which is a partner in the project.
The Barkley Irrigation Company delivers water to users irrigating about 600 acres on the east side of the Methow River. Historically, each July as the Methow River began to approach summer low flows, the company, under a permit from the state, would drive a bulldozer up a side channel of the river to create a large earthen dam to direct water toward the ditch.
The Barkley system has a headgate about a half-mile upstream from the confluence of Bear Creek and the Methow River. Because the first half-mile of the irrigation canal does not have a fish screen, significant numbers of fish are stranded when the ditch is shut down at the end of the season, and must be removed by hand, Penvose said.
“Juvenile spring Chinook, steelhead, adult bull trout and high numbers of Pacific Lamprey ammocoetes (larva) are found in the canal during salvage operations each fall,” according to a recently completed State Environmental Policy Act (SEPA) document on the Barkley project.
Working with Trout Unlimited and other partners, the irrigation company is developing a solution to reduce impacts to fish and reduce the amount of water taken from the river, while ensuring “viable irrigation and agriculture” in the area it serves, according to the SEPA document.
New diversion point
The diversion point for the Barkley system will be moved about 4 miles downstream of the current diversion, taking water out at the existing Methow Valley Irrigation District (MVID) diversion near the south end of the Methow Valley State Airport.
That diversion was built more than a decade ago with a capacity of 30 cubic feet per second (cfs), but major water conservation efforts by MVID, which has piped most of its ditches in recent years, means that MVID doesn’t need to divert as much water, Penvose said. The diversion will provide for up to 16 cfs for Barley and 12 cfs for MVID.
Water for the two irrigation companies will be diverted into pipes that will be buried and run parallel to each other down the valley to Mill Hill, located across the river from the Twisp Park. The project will enclose 4 miles of MVID ditch that are still open. Running two smaller pipelines will be less expensive than one larger one, Penvose said.
The irrigation water for the two companies currently flows into in a single ditch about 2 miles above Mill Hill, where the two pipelines will come together.
In addition, a pump station will be installed near the MVID headgate to feed a smaller pipeline that will push water up to several landowners with property above the grade of the new Barkley pipeline, Penvose said. At the upper end of the Barkley ditch, closer to Winthrop, plans call for serving Barkley members by individual wells to reduce the amount of pipeline construction needed.
“Completion of this work will fully enclose both irrigation purveyors’ systems and complete their efficiency upgrades,” the SEPA document said.
The past practice of constructing the temporary dam channeled a significant portion of the water in the mainstream of the Methow River into the side channel leading to the Barkley headgate, Penvose said. That impacted important habitat for salmon and steelhead, and in 2012 federal fisheries officials said the dam-building had to end.
Trout Unlimited, Methow Conservancy and Bureau of Reclamation worked with Barkley to find a temporary solution, installing a large pump downstream of the headgate to pull water out of the river and dump it into the canal to augment the flow. But it was clear that a longer-term plan was needed, Penvose said.
In addition to reducing the amount of water diverted from the Methow River and eliminating the problem of fish becoming stranded in the upper part of the canal, the project will allow planned habitat restoration by Methow Salmon Recovery Foundation to take place in the side channel above the headgate, Penvose said. The concrete headgate structure, built in the 1940s or 1950s, will be removed as part of the project.
Moving the point of diversion downstream means that more water — about 26 cfs — will remain in the river for that stretch. Instream flows will benefit permanently by at least 6 cfs as a result of improved efficiency, according to the SEPA document.
Penvose said the piped system provides the benefit of an “on-demand” service, where water moves through the system only when needed, as opposed to the open ditch which must constantly carry a certain capacity of water during irrigation season.
Barkley Irrigation Company has about 40 shareholders, and most of the 600 irrigated acres belong to three ranchers and hay growers, Penvose said.
The improvements to Barkley will cost about $5 million, with funding coming from Bureau of Reclamation, Bonneville Power Authority, Confederated Tribes of the Colville Nation, Chelan and Douglas County Public Utility Districts, Natural Resource Conservation Service, National Fish and Wildlife Foundation, Priest Rapids Coordinating Committee, Department of Ecology, Washington State Conservation Commission, U.S. Fish and Wildlife Service, Salmon Recovery Funding Board and Trout Unlimited, Penvose said. He said work on the project will likely begin next year.