Critical Aging Irrigation Infrastructure Assessment

Trihydro undertook a statewide assessment of Wyoming’s critical and aging irrigation infrastructure to identify structures needing repair or replacement.

The Wyoming Water Development Commission (WWDC) contracted Trihydro to complete a statewide assessment of critical and aging irrigation. Functioning irrigation infrastructure is vital to Wyoming’s economy, and much of its infrastructure is over 100 years old. This project identified essential irrigation structures needing repair or replacement to proactively prevent structure failures. Our team developed a list of critical irrigation structures within the state to help the WWDC and the Wyoming Legislature understand the magnitude of statewide aging irrigation infrastructure issues.

Public Outreach

The project included extensive public outreach to gather input on aging infrastructure. The team called more than 150 irrigation entities and conducted 10 public meetings across the state. We coordinated with WWDC, conservation districts, the Bureau of Reclamation (USBR), the State Engineers Office (SEO), and the Natural Resources Conservation Service (NRCS) to provide presentations on funding opportunities, a project overview, and question-and-answer sessions. Our team also prepared project branding, website content, and public relations materials, including press releases, meeting flyers, and social media graphics.

Critical Structures Database

Trihydro developed a comprehensive critical structures database based on information compiled from multiple sources, including previous WWDC irrigation district master plans and watershed studies, site visits, field data collection, the WWDC biannual irrigation system survey, the Wyoming SEO Safety of Dams Program, USBR, and irrigation entities. The database includes over 7,000 irrigation structures.

A major project component included defining “criticality” to develop a prioritization approach to rank critical and aging irrigation structures within the database. A modified Rehabilitation Priority Index (RPI), a common method used on previous WWDC irrigation master plans, was used for the prioritization approach. The RPI uses an algorithm that considers, at a minimum, structure identifiers, structure condition, structure type, condition source, and dependent irrigated acres. These attributes were used to rank rehabilitation priorities. Conceptual designs, costs, and a review of project feasibility were prepared for the top-ranked structures. Feasibility considerations included review of fundability, consequences of failure, permitting challenges, cost per water user, etc.

Additional Services

Additional project tasks include providing recommendations to WWDC for maintaining the database, potential changes to the irrigation systems survey, and recommendations for consistency with this project and future master plan studies.