UCRAF-DST Phase 2 (2025-2027)
Precision has had the pleasure of developing a state-of-the-art tool for the Colorado River Authority of Utah (CRAU) in their effort to plan for and understand drought mitigation strategies in basins that are located in the Colorado River Basin in Utah. Teaming up with Follum Hydrologic Solutions (FHS), the Utah Colorado River and Forecast Decision Support Tool (UCRAF-DST) has been developed and used as part of strategic planning for the CRAU. The UCRAF-DST analyzes agricultural use in the Colorado River basin of Utah at a field scale to understand the impacts of drought mitigation methods in a forecasting planning manner.
The UCRAF-DST allows the CRAU to use an ArcGIS Pro interface to integrate a Diversion-Runoff Calculator to estimate change in consumptive use and an accounting enabled planning model built in RiverWare©. This process, DRC development, a RiverWare model, and output visualization, has been developed and can be used in the Duchesne River basin, the Price River basin, and is near completion for the San Rafael River basin. Those systems were developed in the first three years of contract with the CRAU. In the next two years, the Precision team and FHS will continue working with the CRAU to continue the UCRAF-DST development under the following activities:
Develop the DRC to work for the entire Colorado River basin in Utah so any field that is located within that boundary can be evaluated.
Develop an accounting planning RiverWare model for the Brush Creek and Ashley Creek basins so administration and accounting can be evaluated as part of UCRAF-DST planning and understanding
Develop a Utah Colorado River basin RiverWare accounting model that will evaluate the simulated planning of conservation water, as part of drought mitigation programs, and how that would flow through the remainder of the basin and into Lake Powell. This model will help plan and evaluate how programs may manifest as storage in a destination reservoir and how the conserved water may take losses as it is stored and flows through the basin.
The UCRAF-DST integrates a Diversion-Runoff Calculator (DRC) developed by FHS, and a water rights and accounting model built in RiverWare® by Precision. The DRC has been built to determine Net Irrigation Water Requirement (NIWR) at the field scale, which is aggregated to the canal- and basin-scale. It is a geospatial tool, incorporating irrigated land use data, water rights information, and canal connectivity data. The DRC is capable of estimating NIWR by incorporating field and canal attributes such as crop type, irrigation type, acreage, water rights, canal length, canal type, and location. This data is incorporated with historic data to estimate Evapotranspiration (ET). Alternatively an estimate of ET from OpenET can be used to determine the NIWR. Lastly, the DRC estimates return flows to each adjacent field, canal, and stream reaches.
The RiverWare model ingests data from the DRC including estimates of NIWR, Canal Losses, and return flows. The RiverWare model uses this information to estimate stream flows, diversions, and water rights administration in the basin over the historical period. The tool then allows for perturbations at the field level in the form of fallowing, changing of crop type, or changes in conveyance characteristics to determine a changed NIWR. That new requirement is passed to the RiverWare model and a drought mitigation strategy can be compared to the baseline characterization. The comparison of the baseline simulation to the changed allows the Authority to analyze potential drought mitigation strategies.
The UCRAF-DST is a state-of-the-art model that estimates Natural Inflows to a basin, characterizes the mass balance of the basin physically. The UCRAF-DST characterizes physical and administrative changes to the system, enabling estimates of conserved water. Estimates of conserved water is crucial to the CRAU to assess different drought mitigation strategies that have been proposed through new programs and legislation within the State of Utah.
