Presenter: Amber Spriggs, Water Resources Engineer — Precision Water Resources Engineering

The Utah Colorado River Accounting and Forecasting - Decision Support Tool (UCRAF-DST) is a RiverWare-centered modeling system built for the Colorado River Authority of Utah (CRAU) that enables users to devise and assess different drought mitigation strategies within the Colorado River Basin in Utah. The UCRAF-DST modeling system combines the Diversion-Runoff Calculator (DRC), a geospatial analysis tool which simulates field-scale characteristics and physical processes, with a suite of RiverWare rule-based accounting-enabled administrative models. In this presentation, we will demonstrate a novel technique for launching and running the UCRAF-DST RiverWare models through a GIS interface. We will describe the flow of data from initialization in GIS, through simulation in RiverWare, and into visualization of geospatial results in PowerBI. Finally, we will discuss insight gleaned from the results of simulating example drought mitigation scenarios.

UCRAF-DST modeling systems have now been built for the Duchesne, Price, San Rafael, Brush Creek, and Ashley Creek basins, which are the main tributaries of the Green River in Utah. Additionally, a mainstem model has been built to route output from each of the individual basins through the Green and Colorado Rivers and ultimately compute an estimated drought mitigation volume stored in Lake Powell for any simulated water conservation scenario. This mainstem model includes a mechanism for transit loss accounting. The UCRAF-DST is designed to be executed from Esri's ArcGIS Pro Graphical User Interface by invoking a set of Toolboxes that run a user-defined RiverWare model as a batch process initiated via RiverWare Command Language (RCL). Running the UCRAF-DST models through ArcGIS Pro allows users that are more comfortable with GIS user interfaces to easily evaluate drought mitigation strategies at different scales. We will conclude by discussing results of large-scale scenarios such as basin-wide irrigation method and crop type changes, and small-scale scenarios such as distributed fallowing, that showcase the benefit of coupling the DRC's complex geospatial analysis with sub-basin specific administrative policies in RiverWare.