TWIN FALLS - Decades of hands-off aquifer management are about to end.

After years of failed attempts to pass aquifer-related legislation, the 2006 Legislature passed Senate Concurrent Resolution 136. It instructed the Idaho Department of Water Resources to develop an aquifer management plan for presentation to the 2007 Legislature. Lawmakers will use the plan as a model for aquifer legislation.

At stake is the management of the Eastern Snake Plain Aquifer that supplies water to Idahoans across the south-central part of the state.

The board hired a Boulder, Colo., firm, CDR Associates, to facilitate the process. To date, they've gathered input from more than 100 interested parties that include farmers, politicians, domestic water users, water-dependent industries and environmental groups.

"Right now, it's all in the hands of the facilitators," said Michael Keckler, spokesman for the IDWR.

The facilitators are operating under this goal: to "sustain a balance between water users and supplies so that the economic viability and social and environmental health can be maintained."

Easier said than done.

The plan needs to be in concert with Idaho water law, which is in a state of flux until the state Supreme Court rules on a case that will determine how water is distributed between senior - and junior-right holders. The Idaho Ground Water Act and rules that govern groundwater management areas also put restrictions on the plan.

Further complicating matters, the Legislature asked the board to submit funding suggestions for any management strategies. Where the money will come from is almost as hotly contested between interested parties as how to run the aquifer.

Funding any management plan will be complex. Some have proposed an increase in the sales tax. Others want to create a market where water is bought and sold.

The board also must consider aquifer-related programs already in place, namely a Conservation Reserve Enhancement Program that buys out groundwater users who agree to stop farming their land and stop irrigating in exchange for government money.

The management plan will likely feature alternatives to a main management strategy. Those alternatives are being developed in meetings of stakeholders hosted by CDR.

The plan also will address interim management strategies that could be implemented while the Legislature reviews the proposal. Those include increasing CREP participation, developing mitigation plans between junior and senior water-right holders and implementing an interim recharge project.

In November, the water board voted to fund studies for three proposed recharge sites, one of which may be built near Jerome.

Idaho's first and only state-run recharge site, W-Canal near Wendell, is already in the study stage.

The aquifer is like a giant underground sponge made of porous basalt that stretches from Ashton to King Hill. It covers about 10,800 square miles. Enough water to fill Lake Eerie lies in the uppermost 500 feet, though the aquifer is as deep as 5,000 feet in some places.

Water levels in the aquifer have been in steady decline since the 1950s, when farmers began drilling wells and drawing irrigation water. The declines increased two decades later when many farmers switched from flood irrigation to sprinkler irrigation. Scientists estimate that about 60 percent of water recharged into the aquifer today comes from excess irrigation water and leaky canals.

Water naturally emerges from the aquifer at springs like the ones at Thousand Springs near Hagerman. Spring discharge levels follow the same downward trend as aquifer water levels. That's why photos of the springs taken more than 50 years ago show water cascading all along the Snake River Canyon wall near Hagerman. Today, only a few remaining springs power aquaculture in the area.

The ESPA management plan is expected to be finalized before the Legislature convenes Jan. 8. Lawmakers are expected to review the plan and pass legislation to implement the board-recommended strategies.

Times-News staff writer Matt Christensen covers natural resources. Contact him at 735-3243 and at matt.christensen@lee.net.