Greenfields Irrigation District, Teton and Cascade Counties

Background

The Greenfields Irrigation District (GID) was established in 1926 and currently irrigates over 93,000 acres using water from the Sun River watershed. The alluvial terraces that form the Fairfield bench are primarily recharged by applied irrigation water and leaking canals of the GID. Recent low-water years have highlighted the importance of irrigation in supporting the public water supplies (PWS) that use the Fairfield terrace aquifers; the PWS have struggled to provide sufficient water in the winter and spring prior to the start of irrigation.

Purpose

This project was developed to understand the role of irrigation timing in recharge to the public water supplies of the Town of Fairfield and TriCounty and to use numeric modeling to investigate potential managed recharge methods.

Project Scope

The project area includes the irrigated land of the Fairfield bench; field measurements will include focus areas around the area's public water supplies. A numeric groundwater model will be developed beginning in 2026.

Project Status

The project is actively collecting field data; field work will continue through mid-2026.

Project Reports

• Greenfields Irrigation District Project Factsheet
  View Report

Project Personnel

Elizabeth Meredith	Project Lead, Research Hydrogeologist
Jenna Dohman	Assistant Research Hydrogeologist
Todd Myse	Associate Research Hydrogeologist
Brett Oliver	Assistant Research Hydrogeologist, Groundwater Modeler
Tyler Storey	Professional Scientist Research Hydrogeologist

Presentations

• Greenfields project introduction. Presented to the Sun River Watershed Group water management spring meeting, April 16, 2025.
  View Presentation

Link to Project Data

Data collected for this project can be accessed through the Ground Water Information Center (GWIC) database:

Download project data from GWIC