Efforts to return the Snake River Plain Aquifer to sustainable levels are on target, but more recharge capacity is needed to reach the long-term goal.
In a report requested by Idaho House Speaker Scott Bedke, the Idaho Water Resource Board detailed significant progress toward implementation of the management goals outlined in the 2009 ESPA Comprehensive Aquifer Management Plan.
The long-term goal is to increase aquifer levels by 600,000 acre-feet annually by 2030 to restore the groundwater source to sustainable levels.
The board reported it has reached an annual average water budget of more than 550,000 acre-feet for the aquifer through groundwater-use reductions and managed recharge.
“The ESPA CAMP is the foundation for creating a sustainable water supply for southern Idaho. Our report demonstrates the plan is working,” Roger Chase, IWRB chairman, said in a press release accompanying the report.
The plan includes IWRB-managed recharge, demand reduction, groundwater-to-surface water conversions and cloud seeding to turn the tide on the declining aquifer.
IWRB’s managed recharge program currently has the capacity to recharge an annual average of 202,000 acre-feet, which accounts for both wet and dry years. Its goal is to recharge an annual average of 250,000 acre feet, and more capacity is needed to take advantage of wet years to offset limited recharge in dry years.
Projects are underway to accomplish a substantial portion of the needed capacity, but continued funding will be needed, the report’s authors stated.
Another major action to restore the aquifer is the 2015 historic settlement agreement between the Idaho Ground Water Association and the Surface Water Coalition in which groundwater users agreed to a net reduction of 240,000 acre-feet annually.
“We compliment the board for all of their work, and we need to keep pushing ahead toward ESPA sustainability,” Lynn Tominaga, executive director of the Idaho Ground Water Association, said.
A separate settlement agreement with South West Irrigation District reduces diversions by more than 6,000 acre-feet.
Conversions from groundwater to surface water through settlements with the Surface Water Coalition account for more than 87,000 acre-feet in the water budget. In addition, other settlement agreements contribute more than 18,000 acre-feet through reductions and recharge.
“The CAMP is working; the science says it’s working,” Brian Olmstead, general manager of the Twin Falls Canal Company and a spokesman for the Surface Water Coalition, said.
“We are all working together. We applaud and support the board’s recharge program and other initiatives. We need everybody who’s involved in stabilizing the aquifer to continue their work,” he said.
IWRB has not yet determined to what extent cloud seeding enhances the aquifer beyond augmenting surface-water supply.
To date, IWRB has received more than $54 million from the Idaho Legislature for aquifer initiatives. About $35 million of that has been spent or committed on the ESPA, including $29 million allocated for recharge.