Study of aquifer looks at the future

When scientists undertake a $3 million study of the Spokane Valley-Rathdrum Prairie Aquifer, they’ll examine how climate change could affect the drinking water supply for more than 500,000 residents.

“It’s an inexact science to be sure, from the standpoint of looking at the future availability of water,” said Hal Anderson, an administrator for the Idaho Department of Water Resources. “The main change we anticipate with warmer weather is the runoff coming sooner.”

Climate change is just one part of the four-year study, conducted by the Idaho Water Resource Board. Scientists also will examine how Lake Coeur d’Alene and Lake Pend Oreille contribute to groundwater flows; how much water Idaho users draw out of the aquifer; and how population growth will affect demand for water.

The study targets the Idaho portion of the 326-square-mile aquifer, which straddles the Idaho-Washington line. The work is a follow-up to the recent $3.5 million, two-state study that characterized groundwater flows and the aquifer’s interaction with the Spokane River. Anderson said the new study will attempt to answer questions posed by findings from the two-state study.

The study began this month. The state of Idaho plans to spend $30 million on multi-year studies of 10 major aquifers around the state. Aquifers in the Rathdrum Prairie and Southern Idaho’s Treasure Valley are the first priorities, because of rapid population growth in both areas, Anderson said.

In addition to gathering data, the studies will make recommendations for aquifer management to to the Legislature.

“We’ll end up with a comprehensive aquifer plan,” Anderson said.