Snowpack lower than average, but water supply looks sufficient
At first glance, Idaho’s 2009 water supply appears to be sufficient to meet agricultural demands for the upcoming growing season, but appearances can be deceiving especially in Idaho.
The Natural Resources Conservation Service’s (NRCS) Feb. 1 report on Idaho’s water supply said snowpack levels averaged between 80 percent and 100 percent in most areas, with Camas Creek, Big Wood River below Magic Dam and the Bear River at Stewart Dam the lowest basins with snowpack averaging about 60 percent.
The Bureau of Reclamation’s current report on major storage reservoirs in the Upper Snake River Basin indicates that most of the reservoirs are nearing capacity, with Henrys Lake at 97 percent; American Falls, Grassy Lake and Island Park more than 85 percent; and Jackson Lake at 76 percent. Palisades is holding at 67 percent, Ririe at 52 percent and Lake Walcott at 41 percent.
It’s still too early to state unequivocally that the state has enough water for the year, but current indicators point to potentially sufficient water.
Hal Anderson, division administrator for the Idaho Department of Water Resources (IDWR), is cautiously optimistic when assessing the state’s overall water supply for the upcoming year. Anderson said the state had a good December and early January, with heavy snowpack in the mountains. The second half of January and February were setbacks for the state, with little additional snowpack.
Overall, we’re a little less than average,” Anderson said.
Despite the lack of precipitation, the state can get by thanks to a good water year last year combined with a cool spring, resulting in a surplus at the end of the growing season, he said.
“We went into this year with a good carryover in our reservoir systems,” Anderson said. “So, at this point we don’t anticipate any major problems. However, we’re not going to have an abundance of supply, either.”
Anderson said the fact that the Snake River basin above the Palisades Reservoir is projected to be a little over 90 percent of average is a good sign, because “we’ve got major storage area over there.”
In Idaho, there is the looming shadow of potential water calls on junior water users by seven organizations with senior water rights, known collectively as the Surface Water Coalition.
Last October, IDWR mailed letters to 1,700 water-right holders, warning them of the potential curtailments of their water rights.
Anderson was noncommittal when asked about the potential curtailment.
“We won’t make that decision until April 1,” he said. “The director will be looking at that particular water supply for the surface water coalition members and then make a determination at that point in time. If that water supply is sufficient to satisfy their demands (and) if the reservoir systems fill, there will be no need to curtail. If the reservoir system looks like it might not fill, there might be some mitigation required.”
Once IDWR gets the reports from NRCS and the Bureau of Reclamation, the director will make a final decision regarding the water call, Anderson said.
“Given the carryover storage, we don’t need 100 percent,” he said. “We can get through particularly on the surface water coalition calls on something less.”
