This article was published on: 08/3/22 9:56 AM
Six-year project will save 2.8% of the district’s average annual diversions
A Jefferson County irrigation district project that will upgrade and modernize portions of its water delivery system has entered a public comment period that will conclude on Aug. 10.
The public is currently allowed to comment on a draft Watershed Plan Environmental Assessment for the project, which will install 27.5 miles of gravity-pressurized, buried pipe along the North Unit Irrigation District’s laterals 31, 32, 34, and 43. Laterals are the ditches that deliver water to farms.
These laterals were chosen for upgrading after studies showed they had some of the highest water loss in the system.
“These are the projects that will give us the most bang for our buck,” Josh Bailey, North Unit’s district manager, said during an information session about the project.
In addition, 153 turnouts would need to be upgraded to accommodate the pressurized system.
Turnouts, also known as delivery gates, are the point at which control of the water switches from the irrigation district to the customer. This is typically where a valve is placed to adjust the flow rate of the irrigation water. A device can also be placed here to determine the flow rate.
The project will also build four 1,000-cubic-yard retention ponds, each a half acre in size. These ponds are designed to eliminate discharges from operational spills into water bodies, including the Crooked River and Lake Billy Chinook.
Converting the open-ditch irrigation laterals into a buried, closed-pipe system will help the irrigation district reduce water loss from seepage and evaporation, and save an estimated 6,089 acre-feet of water annually, or 2.8% of the district’s average annual diversions.
To date, North Unit has lined and piped around 50 miles of its roughly 300-mile network of canals and laterals.
The pipes to be installed in the planned project are smaller than the ones typically used for large-scale piping projects — they range in size from 6 to 72 inches in diameter, according to the draft environmental assessment.
For North Unit, a junior water rights holder in the Deschutes Basin, the water savings are critical for increasing allotments to farmers during times of drought. This year North Unit patrons are receiving a quarter of their normal allotment due to drought and a lack of storage water in Wickiup Reservoir.
North Unit Irrigation District provides water to 59,000 acres of Central Oregon’s most productive farmland.
The 6-year modernization project would require $25.8 million in federal funding and another $8.2 million in district matching funds, for a total of $34 million.
The Deschutes Basin Board of Control is sponsoring the project and North Unit’s role is the project co-sponsor. The proposed improvements may be partially funded through the Watershed Protection and Flood Prevention Act of 1954.
The draft plan environmental assessment can be viewed online at oregonwatershedplans.org.
Comments about the project can be submitted by phone by calling 541-716-6085, emailed to northunit.id.comments@gmail.com or submitted online through oregonwatershedplans.org.
-Michael Kohn