Saturday, June 2, 2012

Study Warns: Wells Saving Crops but Depleting Aquifer

After a dispute in 2001 that drew national attention to the Klamath Basin and its struggle over divvying river water for the benefit of fish, waterfowl and farmers, irrigators started digging wells to water their crops in dry years.

Now, a federal study has concluded they have pumped more than the regional aquifer can sustain.

In 2010, a drought year, the water level dropped 10 to 20 feet in some places — which was below the wellhead in the farming community of Merrill.

While the city sank pipes deeper into the well, residents for several days used bottled water for cooking and cleaning.

The study done by the U.S. Geological Survey is aimed at showing how much the irrigators can use in dry years without jeopardizing municipal supplies or depleting the aquifer, the Klamath Falls Herald and News reported.

“There is a substantial resource there, and it can provide water for the long term,” said Marshall Gannett, a hydrologist for the agency who has spent half of his career studying the Klamath Basin. “(Groundwater) can be managed in a way that you can get substantial volumes of water when you need it in dry years.”

Pumping water for crops in the Klamath Project is relatively new. Irrigators dug wells throughout the Basin in 2001, when a severe drought left them without surface water.

The Tulelake Irrigation District dug 10 wells that year and has seen a steady drop in the aquifer since then, especially after 2010, said Brad Kirby, assistant to the district manager.
In 2010, Klamath Project irrigators pumped more than 100,000 acre-feet of groundwater. An acre-foot is the amount of water that could cover an acre one foot deep. It amounts to about 43,000 cubic feet.

This year, with another water shortage projected, plans call for project irrigators to pump 40,000 acre-feet.

The study says irrigators can pump about 56,000 acre-feet of water in an average year, about an eighth of the project’s annual demand.

But, Gannett said, the average contains wide variations from year to year, and less water is available when the aquifer is depleted from drought or from previous pumping.

Henley-area hay and potato farmer Ed Bair says he plans to use his groundwater well if there is a shortage of surface water this year.

“If we manage it right, it can last us a long time,” he said. “If we don’t, it can be short-lived.”

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