ESPA Achieves Record Recharge

For over half a century, the question of how to conserve and replenish water in Idaho’s largest aquifer, the Eastern Snake Plain Aquifer (ESPA), has been on the collective minds of the state’s water users. Serious droughts in the 1990s increased pressure on the ESPA resource, and preliminary recharge efforts were unsuccessful. Finally, in 2009, the ESPA Comprehensive Aquifer Management Plan, otherwise known as CAMP, was signed into law. CAMP’s goal is to annually recharge 100,000 acre feet (af) during the first ten years of the plan’s implementation, followed by 250,000 af per year thereafter.

The recharge comes from a combination of sources. The Idaho Department of Water Resources (IDWR) also supports canal companies and irrigation districts recharge projects, rotations and efficiency reductions.

The 100,000 af goal was not quite reached in the first few years. Recharge was roughly 75,000 af in both the 2014-2015 and 2015-2016 seasons. However, the 2016-2017 saw 317,000 af returned to the ESPA, far exceeding the 100,000 af goal. The 2017-2018 season is shaping up to be even better. Over 350,000 af have already been replenished.

ESPA’s recharge success is good news for the residents of southern and eastern Idaho, and Idaho in general, as roughly 25% of Idaho’s economy is dependent upon agricultural output from the region. Unfortunately, CAMP’s success in the ESPA has not been matched by similar programs throughout the state and region. The Rathdrum Prairie Aquifer (RPA) in the northern part of the state, which is responsible for roughly 8% of Idaho’s production of goods and services, has a CAMP program in place. However, the RPA has not been nearly as successful as the ESPA at achieving substantial recharge. Another CAMP program has been proposed for the Treasure Valley, but has been delayed due to ongoing discussion between legislators and constituents.

In Washington, the Odessa Groundwater Replacement Program (OGWRP) was implemented to reintroduce water back into the Odessa Aquifer. Several initiatives under the umbrella of this program have been enacted, and have had reasonable success. However, efforts have focused more on limiting usage of the aquifer rather than reintroducing water back into it. Oregon has also taken steps to encourage recharging of its aquifers. However, as illustrated by the attempts in the Umatilla Basin, these programs have struggled to achieve significant recharge.

CAMP’s success did not come overnight. As with any major experimental project, it took decades of planning, communication, and compromise to achieve the ESPA’s level of recharge. Nonetheless, the potential for aquifer recharge demonstrated is inspiring, and will hopefully pave the way for similar projects throughout the West.

Stay tuned to Schroeder Law Offices’ Water Law Blog for more news and events!