Irrigation Leader Magazine – See pages 8 – 12 to read the interview of Lorri Gray, Secretary/Treasurer of NMID. She talks about the Ridenbaugh Headworks Modernization Project and the priorities of the Nampa & Meridian Irrigation District.

Progression of Headworks from the beginning

Ridenbaugh Headworks Progress as of March 2026

Ridenbaugh Headworks Groundbreaking Ceremony on October 14, 2025

Farm Bureau Summary of Ridenbaugh Groundbreaking

After 120 years of successfully delivering water to landowners across the Treasure Valley, the district is starting a project to replace the Ridenbaugh Headworks. The Headworks allows water to be diverted out of the Boise River into the Ridenbaugh Canal for delivery to landowners. This project will improve worker and public safety, increase operational efficiency, reduce operational water loss, and increase flexibility to respond to changing Boise River flows. Most importantly, NMID wants to ensure we can deliver water to landowners for the next 120+ years.

In-river construction began in October 2025. Over the winter, the inlet channel and base for the two 40-foot crest gates were completed. An access road on the north side of the river and a control building will be completed in July/August 2026. At the end of the 2026 irrigation season, in-river construction will begin again. This work will include the installation of the crest gates, installation of the intake screens and construction of an 80-foot ogee weir. All in-river work is expected to be completed by April 2027.