Henrys Fork Basin Study

The Bureau of Reclamation and the State of Idaho, in collaboration with a stakeholder working group, will conduct a study on water resources in the Henrys Fork River basin to develop alternatives to improve water supply conditions in the Eastern Snake Plain aquifer (ESPA) and Upper Snake River basin in accordance with the ESPA Comprehensive Aquifer Management Plan (CAMP).

The study area is upstream of the Henrys Fork River’s confluence with the Snake River and includes the North Fork of the Upper Snake River, Fall River, and Teton River watersheds. It is also situated above part of the ESPA.

The study will identify opportunities for development of water supplies (i.e., above-ground storage, aquifer storage) and improvement of water management (i.e., conservation measures, optimization of resources) while sustaining environmental quality. Alternatives will be developed in accordance with the managed aquifer recharge program of the Idaho Water Resource Board and the goals of the ESPA CAMP, and in consideration of the environmental impacts to the entire Snake River basin. The objectives of the study are to assist future planning efforts and to provide specialized information that can be used for future decision-making processes at the state and local levels.

Federal water development projects on the Snake River above Milner Dam near Burley, Idaho provide full or supplemental water supply to more than one million acres of irrigated land. Over 1.4 million acres are irrigated by privately developed irrigation systems from natural flows in the Snake River and its tributaries or groundwater from the ESPA.

The analysis of water supply and storage will involve identification and evaluation of watershed hydrology and potential onstream and offstream storage sites. The focus will be on the availability, characterization, and quantification of the natural hydrology of the basin, including:

• seasonal volume of runoff and stored water available;
• surface water/groundwater interactions;
• irrigated agricultural areas;
• instream and offstream water uses;
• irrigation water distribution facilities and their operation; and
• the current characteristics and quality of riparian habitat.

The study is expected to be complete by the end of 2013.