Water technicians are traveling across southern Idaho this week and next to measure groundwater levels in 1,400 wells.
The U.S Geological Survey and the Idaho Department of Water Resources are conducting a widespread survey from Glenns Ferry to Island Park and from Twin Falls to Mackay. The technicians look at wells used for irrigation and domestic water, many of which are on private property.
The workers send steel or electric tape down the wells to measure how deep water in the Eastern Snake Plain Aquifer is from the surface.
“They range anywhere from a pressure reading to just a couple feet below land surface to all the way down to just over 800 feet,” said Amy Wehnke with the USGS.
The agencies monitor groundwater levels frequently, but this particular project only happens every five years. It's unique because the measurements are gathered across an area that covers roughly one million acres of farmland, and within a particular time period, specifically, before irrigation season begins.
That’s so they can get a “snapshot” of aquifer levels without the effects of groundwater pumping.
The data will help re-calibrate the model used to determine the health of the Eastern Snake Plain Aquifer, which is the primary source of drinking water for about 300,000 people. Since the 1950s, water levels in the aquifer have seen a significant decline.
The model helps the Department of Water Resources manage water use and water disputes. Idaho code recognizes the interconnection between ground and surface water, and declining aquifer levels could have an impact on the amount of water in rivers and canals.
It also helps the department understand how aquifer recharge – or sending surface water back underground for storage – is working, and how the state’s program can be improved.
Find reporter Rachel Cohen on Twitter @racheld_cohen
Copyright 2023 Boise State Public Radio
