San Juan River Basin, New Mexico

Hydros has been helping the New Mexico Interstate Stream Commission (NMISC) address its water management issues for more than two decades. We were recently tasked with developing a surface water model of the San Juan River basin within New Mexico to assist the NMISC with long-term planning, water rights administration, and operational coordination with Reclamation regarding operations of Navajo Reservoir. The model, developed using the RiverWare modeling platform, is a daily time step model that simulates administration of water rights under New Mexico water law, storage and releases of Navajo Reservoir water for Reclamation contractors including the Navajo Nation and for ESA flows pursuant to the San Juan River Basin Recovery Implementation Program.

The model domain includes the Animas River from the CO-NM Stateline to the San Juan River confluence, and the San Juan River from Navajo Reservoir (including reservoir storage and tracking inflows into the reservoir) to Shiprock, NM, including all the major reservoirs and diversion points both for agricultural and municipal uses. The Navajo Indian Irrigation Project (NIIP) is included in the model. The model is being used to evaluate the effectiveness of shortage sharing arrangements in the Animas River in lieu of strict priority administration, impacts of potential future growth, and tracking water leases from the Jicarilla Apache Nation to the State of New Mexico that are being used to enhance endangered fish habitat in the San Juan River. A near-term operations version of the model is being developed that will use streamflow forecasts and water user orders to develop annual operating plans and perform water supply accounting in near-real time.