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Runoff predictions higher for Midvale
Feb 22, 2013 - By Eric Blom, Staff Writer
The drought did not lessen the water Midvale Irrigation District diverted last year, and the Bureau of Reclamation expects runoff into the Midvale system to be greater in 2013. Officials delivered reports on water to the annual membership meeting of Fremont County's largest irrigation district Feb. 14 at the Pavillion recreation center.
Coleman Smith of the U.S. Bureau of Reclamation told Midvale officials and 50 members in attendance that snow melt from April through July into the Wind River above Bull Lake Creek should be at 350,000 acre feet. That figure is only 87 percent of the 30-year average of 404,000 acre feet but higher than last year's 317,200 acre feet.
Midvale draws water from the Wind River and Bull Lake Reservoir to irrigate 73,000 acres north of the Wind River on ceded land within the Wind River Indian Reservation boundaries.
Smith made clear, though, the actual number could be well high or below that estimate, and said the minimum expected runoff is 95,000 acre feet.
The USBR bases its estimates on snow pack measurements from the National Resource Conservation Service. An acre-foot is the water needed to cover one acre in one foot of water, or 325,851 gallons.
Smith said the same forecast for Bull Lake Reservoir is 125,00 acre feet, which is 89 percent of the 30-year average but higher than last year's measured 117,500 acre feet. The minimum expected is 250,000 acre feet.
"It's certainly below average; it's certainly no reason to panic," Smith said.
The federal bureau also expects Bull Lake to end the irrigation season holding more water than it did last year, Smith said.
Predictions are uncertain whether spring precipitation will be more or less than normal.
"Right now they're saying equal chances," Smith said, noting predictions were similarly vague at this same time last year.
Irrigation district manager Dick Johnson reported Midvale diverted 343,161 acre feet, which was 97 percent of average.
Diverted water is the amount entering the irrigation district's canal system.
Irrigators received a total of 180,160 acre feet of water last year, an efficiency of 52.5 percent, and 2.43 acre feet per acre. The allotment for users was 3 acre feet per acre.
According to the minutes of 2012's annual meeting, the delivery efficiency in 2011 was higher at 57 percent and irrigators received more than 3 acre feet of water per acre.
Johnson said the efficiency would have been higher, but Midvale passed up using 60,000 acre feet it could have diverted.
"There were rumors we were going to shut down early," he said.
Those rumors led irrigators to limit their use and stretch their allotted amount of water, so the irrigation district board of commissioners tried to encourage more use.
"The board raised the allotment three times," Johnson said, "but we couldn't convince people."
In the end, water required to meet senior, downstream water rights passed Diversion Dam unused.
Johnson also announced Midvale is nearing completion of a major project, the second division drop structure.
The structure can back up water flow, allowing irrigators to draw water from behind it, and drops the canal's elevation. It is a 126-foot long, roughly 8-foot wide downward sloping concrete tube with a gate on the upstream end and a baffle on the other.
Midvale office manager Pat Rorabaugh said the previous structure was damaged. If it had washed out during the irrigation season, she said, users north of Pavillion would have been out of water.
Midvale commission president Gordan Medow also announced Dick Johnson will retire soon, and Jon Howell will be replace him as district manager starting March 10.