Mass test to determine health of eastern Snake aquifer
By SEAN ELLIS
U.S. Geological Survey and Idaho Department of Water Resources officials are asking for landowners' cooperation as they measure groundwater levels in more than 1,300 private and public wells throughout the eastern Snake River Plain in southern Idaho.
The effort will help water officials gain a better understanding of the health of the eastern Snake River Plain aquifer, said Sean Vincent, IDWR's hydrology section manager.
The aquifer, which has an estimated volume of 200 billion cubic feet of water, provides irrigation water for one million acres of farmland and is the water source for the state's aquaculture industry. It is also the area's chief source of drinking water.
The mass measurement is being done "in order to get a detailed snapshot of the overall health of the aquifer," Vincent said. "Everybody wants to know what's going on with the aquifer."
The measuring began April 8 and will conclude April 19.
The data will be used in a variety of ways, including to measure water levels in different areas, determine flow directions and to continue improving the IDWR's computer model of the aquifer. The USGS and IDWR measured aquifer levels in 2002 and 2008 and the agencies plan to continue the mass measurements every five years, Vincent said.
The measuring effort "gives us a better idea of the trend of the aquifer, whether it's going up or whether it's still continuing to decline," said Idaho Irrigation Pumpers Association Executive Director Lynn Tominaga.
Tominaga expects water officials will find that aquifer levels have stabilized or actually increased east of Lake Walcott, while the area west of Lake Walcott has experienced some decline. That assessment is due to more recharge occurring in the eastern part of the aquifer, he said.
"A lot of this area used to be all flood irrigated and ... now it's all sprinkler irrigated," he said while pointing to the western part of the aquifer on a map. There are also a lot more recharge projects going on in the eastern part of the aquifer, he added.
"So because of the recharge that we're seeing through here, I think you'll see a stabilization or actually an increase in the aquifer levels," he said while pointing to the eastern part of the aquifer.
The measuring effort will help the agencies understand what the impacts of recharge have been, Vincent said.
"Water levels are different in different areas of the aquifer. That's why we need to do a complete water level synoptic," he said.
Vincent said IDWR and USGS employees would appreciate well owners' cooperation in the study by granting them access to their wells.
"Privately owned wells are a valuable source of information," he said. "The more wells from which information can be gathered, the better the assessment of the current state of the aquifer will be."
The employees will report the results to the well owner.