Dry Conditions Continue To Persist Across Southern Idaho

The final July curtailment order for Snake River water rights has been issued.  Idaho Department of Water Resources has ordered junior groundwater users to join a mitigation plan or face curtailment. 

Users that draw from the Eastern Snake Plain Aquifer who have joined mitigation plans are protected from the order.

Junior groundwater users who were informed on May 16th of the pending curtailment order have an immediate requirement to join a mitigation plan, while newly curtailed groundwater users effected by the July Curtailment Order, will have a 15-day grace period to join a mitigation plan.

Five groups of groundwater users are protected from curtailment, because they are operating under IDWR-approved mitigation plans. That includes: 

• The Southwest Irrigation District
• Coalition of Cities
• A&B Irrigation District
• Water Mitigation Coalition
• Groundwater Districts

IDWR said the members of the Groundwater Districts are protected under a stipulated mitigation plan approved following completion of the 2024 Water Settlement Agreement. Groundwater users who are subject to this curtailment order are encouraged to join their local ground water district as soon as possible in order to avoid curtailment.

Dry Conditions Continue To Persist Across Southern Idaho

In an order earlier this month, in the ongoing Surface Water Coalition’s conjunctive administration delivery call, Director Weaver found that the Twin Falls Canal Co. may face a shortfall of 75,300 acre-feet of water in the 2025 irrigation season. The Methodology Order is the court-approved process IDWR uses to evaluate water supply conditions and irrigation demand in the delivery call proceedings. From that data, IDWR calculates an in-season demand shortfall, which quantifies the impacts or injury to Snake River surface water users with senior water rights caused by junior groundwater users pumping from the Eastern Snake Plain Aquifer (ESPA).  

Under Idaho water law, surface water users with senior water rights have priority over water users with junior rights on the Snake River and the ESPA. The rule of law is “first in time, first in right.” On the Snake River, IDWR manages both surface and groundwater resources together as one whole, or “conjunctively,” in calculating impacts each year.  

IDWR Deputy Director Brian Patton said it’s important for IDWR to be consistent in its enforcement of the Methodology Order since most junior groundwater users are protected under existing mitigation plans, and their support for those plans will hinge on IDWR’s enforcement efforts to ensure all groundwater users are complying with the order.

By Glenn Vaagen

Read the full article here.