Twin Falls’ future water supply in jeopardy

TWIN FALLS, Idaho – Declining aquifer water levels in southern Idaho mean Twin Falls could run out of water in five years unless new drinking supplies are secured, a study has found.

Boise-based J-U-B Engineers released the study this week that found Twin Falls’ wells will decline in production because of the drought and other adverse effects on the aquifer, a pattern that has already been observed.

“Twin Falls is not alone, if that’s any comfort – it’s happening everywhere,” Bill Block, J-U-B senior project manager, told The Times-News. “Water’s going to be the oil of the 21st century.”

The aquifer has declined steadily as the number of wells has increased and irrigators turn to sprinkler systems rather than flow irrigation. But aquifer levels have dropped even more because of the drought that’s affected the West the past several years.

Twin Falls has four production wells on the north side of the Snake River. Production from those wells has been declining, but it is expected to level off by 2007, according to the J-U-B study. However, four wells on South Washington Street are expected to continue to decline at a rate of about 4 percent per year.

“In the late 1990s, we developed a plan that should have taken care of our water needs for the next 50 years,” said City Manager Tom Courtney. “What we didn’t anticipate, and what has occurred, is the decline in the aquifer and what we have the ability to pump.”

The situation is further complicated by a new federal standard that reduces the amount of arsenic allowed in drinking water. The new standard becomes law in January. Half of the city’s drinking water wells produce water containing arsenic levels above the 10 parts per billion the new standard allows.

According to the study, the city will see a 3.5 million-gallon shortfall in 2010. By 2015, the deficit will be 74.1 million gallons, and by 2035, it will be 797.8 million gallons.

The city uses nearly 5 billion gallons of potable water annually, according to Water Department Superintendent Mike Schroeder.

Besides studying water supplies and arsenic levels, J-U-B was contracted to recommend solutions, and it has developed several options for Twin Falls to meet future needs and reduce arsenic levels. Options include buying water rights from existing well owners, buying and treating surface water from other sources, and drilling new wells that are low in arsenic.