WILLOW CREEK
The Willow Creek drainage is an area of intensive agricultural production in far eastern Oregon. It covers an area of about 500,000 acres.
In the 1990’s, the Malheur Watershed Council and the Malheur SWCD began a program of water quality monitoring that encompassed Willow Creek. The results consistently indicated problems, primarily with bacteria, and a focus group was formed to address the issues. Most of the agricultural activity occurs in the 30,000 acres adjacent to Willow Creek from below Brogan Canyon to the confluence with the Malheur River. This area is where the majority of water quality concerns are.
In response to these issues, the Lower Willow Creek Working Group formed in 2000 under the umbrella of the Malheur Watershed Council. This group consists of local landowners dedicated to promoting practical solutions to water quality and other environmental problems. Since its formation, the working group has sponsored grants for more monitoring, feedlot improvements, irrigation system upgrades, and much more. To solicit landowner involvement, the group conducts town hall meetings, sends out flyers, knocks on doors, and uses word of mouth.
In 2002, the Department of Environmental Quality placed Willow Creek on the 303(d) list for not meeting chlorophyll a (algae) and bacteria standards.
Willow Creek has several water quality and social problems. One is the large number of livestock on feedlots near Willow Creek. The concentration of livestock in the Willow Creek drainage is one of the highest in the state. A consequence of concentrating large numbers of animals in one relatively small area is that animal waste is bound to get into streams. Large feedlots and dairies have already made the improvements needed to protect water quality as a condition of their permit with the Oregon Department of Agriculture.
Current bacteria sources under human control are tail water from flood-irrigated pastures and small lots where contaminated runoff can reach surface waters. An experiment conducted by Dr. Clint Shock and others showed that tail water from irrigated pastures could contain up to 230,000 E. coli colonies per 100 mL of sample. The state’s bacteria standard allows only 406 colonies per 100 mL.
A second problem is irrigation-induced erosion. The most common method of irrigating is called furrow irrigation. This method consists of delivering water to a field via a ditch or pipe. Water is then sent by gravity down a furrow (also called corrugates), a narrow trench made by a plow. Crops are grown on raised beds between the furrows. Massive amounts of soil are carried off the fields by the irrigation water. When water reaches the end of each furrow it is collected in a receiving ditch. These tailwater ditches eventually lead to Willow Creek.
Experiments and computer modeling have shown that soil losses from furrow irrigation can be as high as 15 to 20 tons per acre per year. About 30,000 acres in Willow Creek are furrow irrigated. If every field eroded at 15 to 20 tons per acre per year that would mean 600,000 tons or about 50,000 dump truck loads of dirt potentially enters Willow Creek each year.
A third issue is that a federally listed fish species, bull trout, resides in the North Fork of the Malheur River. Willow Creek irrigators use water from Beulah Reservoir, a dam on the North Fork. Radio tag studies show some bull trout adults leave the reservoir in April-May and reside in upper basin spawning areas throughout the summer where optimum water temperatures for adult bull trout are present. They return to the reservoir in late October after spawning. During drought years, the reservoir levels become too low to provide quality winter habitat for the fish. The water savings from improved irrigation efficiency will potentially help maintain a pool in Beulah Reservoir. This will benefit winter habitat for bull trout populations.
A fourth problem all producers face is the cost of making the necessary improvements to protect water quality. Upgrading from furrow irrigation is particularly expensive. While it is true that producers benefit from irrigation improvements by increased yields and conserving water, the benefits are not great enough for most landowners to convert all on their own. Estimates show it could take as long as 15 to 20 years to recoup a farmer’s investment in a center pivot. This rate of return is not high enough for most bankers to loan, and in a county that ranks the lowest in Oregon for per capita income, the average landowner is not able to make these improvements without help.
The Bureau of Reclamation developed the irrigation system for Willow Creek in the 1930’s and 40’s. It consists of a main canal that the Vale Oregon Irrigation District diverts water from the Malheur River using a low dam constructed about a mile above Namorf Siding on the Oregon Short Line Railroad. Water travels 50 miles from Beulah Reservoir to Namorf, and another 40 miles from Namorf to Vale. From this point of diversion, the water flows down 73 miles of main canal to Jamieson on the west side of Willow Creek. This main canal is designed to carry 1 cubic foot of water per second for each 50 acres of irrigated land. Lateral canals intersect the main canal at irregular intervals to deliver water to individual farms in the Willow Creek and Vale area.
The District has three storage facilities. They are the Warm Springs Reservoir on the Middle Fork of the Malheur River, Bully Creek Reservoir on Bully Creek a tributary of the Malheur River, and Beulah Reservoir on the North Fork of the Malheur River. The total storage capacity available to the District is 185,000 acre-feet. Warm Springs holds 190,000 acre-feet, but half of this capacity is used by other irrigation districts. Thus, only 95,000 acre-feet is available. The Beulah holds 60,000 acre-feet, and 30,000 acre-feet