Idaho pipe project saves water, power
By Cindy Snyder, Ag Weekly correspondent
Monday, December 22, 2008 3:51 PM CST
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CINDY SNYDER/Ag Weeekly
This farm land is now being irrigated using waste water from the North Side Canal Co. That means more water in Birch Creek for aquaculture and hydropower generation plus cleaner water in the river for the Bliss Rapids snail. |
HAGERMAN, Idaho - As the demands for water keep growing in Idaho, finding ways to maximize water use is becoming more important.
For a few irrigators who rely on Birch Creek near Hagerman for their water, the answer to insufficient water supplies lies above them.
Irrigation return flows from the North Side Canal Co. are being trapped behind a dam and then piped to approximately 215 acres below. In addition to supplying 8.5 cubic-feet-per-second of irrigation water, Birch Creek also supplies water for fish-raising ponds and a small hydropower generation plant.
Cliff Jensen owns farmland in addition to the aquaculture and hydropower facilities on Birch Creek. Since 1990, he’s seen flows in Birch Creek decline 32 percent. Spring flows range from 11 cfs in the winter to 4.5 cfs in the summer, not enough to meet the existing water rights.
That’s why he was interested in pursuing the pipeline project. He and the other landowners worked with the USDA-Natural Resources Conservation Service to design an 18-1/2-foot high dam on the Malad Gorge State Park to hold wastewater from the W-Canal. The dam stores approximately 99 acre-feet of water.
Malad Gorge used to be a working farm, said Steve Thompson, district conservationist for the NRCS in Gooding County. All the irrigation ditches that brought water to the fields were still in place and were used to bring water from the W-Canal to the dam.
From the dam, 4,500-feet of 15-inch pipe was laid followed by a couple hundred feet of 12-inch pipe constricting to 10-inch pipe. Because of the fall from the rim, a pressure-relief valve was installed halfway down the pipeline to reduce pressure from around 87 pounds per square inch to 11 psi.
By the time the water reaches Jensen’s fields, the pressure has returned to about 82 psi.
“You’ve got to be careful turning the pump on and off,” Thompson said.
Jensen always thought the project had the potential to be a win-win deal, but says it ended up being a win-win-win-win deal. He was able to use the system for about two months during the 2008 growing season.
Because he is now receiving gravity-pressurized irrigation water, his power bill has been reduced from around $1,000 a month to $22.
“Our only power cost is to move the pivots,” he explained.
That potential energy savings caught the attention of both NRCS and Idaho Power, and both provided cost-share assistance to help pay for the pipeline. A federal water-quality grant was used to help pay for dam construction.
Before the project, irrigation return flows spilled into the Snake River approximately two miles east of the confluence of the Malad and Snake rivers. The U.S. Fish and Wildlife Service has identified this area to be home to the endangered Bliss Rapids snail.
By diverting those return flows to be reused as irrigation water, the return flows are not entering the Snake River any longer. More clear, clean water from Birch Creek enters the river instead.
Thompson estimates there is enough wastewater in the W-Canal to meet Jensen and the other landowner’s irrigation demands for all but a few weeks during the peak irrigation season. During that time, they will pump out of Birch Creek.
“Whatever water is captured here (at the dam) is land applied,” Thompson said. “And the irrigators are required to manage their irrigation water to minimize spill.”
Since the dam was completed and the reservoir began to fill, Jensen said flows in Birch Creek have increased and he wonders if the spring is getting incidental recharge from the dam. The wetland area behind the dam is also trapping sediment and other nutrients so the water coming through the pipeline is very clean.
“We haven’t had any problems plugging up nozzles,” Jensen said. “This turned out to be quite a bit more of a project than we had anticipated. But it really works good.”
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