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Show Final Report Hydrologic Model Analysis of the Provo River Basin 5.0 SUMMARY OF CURRENT AND FUTURE USES OF THE MODEL This Hydrologic Model Analysis was conducted to develop a modeling tool that would assist in the analysis of future impacts associated with the completion of the Central Utah Project and to provide ongoing assistance to the CUWCD in its management of its Provo River system water resources. As described in the following sections, the Provo River Simulation Model is currently being used to meet these objectives. 5.1 Use of PROSIM in the WCWEP and DRP EISs The first application of PROSIM after development and calibration was in the Wasatch County Water Efficiency Project and Daniels Replacement Project Environmental Impact Statement ( WCWEP/ DRP EIS). The EIS ( CUWCD, 1996) concerns the effects of two separate, but linked, proposals on the Provo River system: an agricultural water conservation project and a project to eliminate an environmentally harmful transbasin diversion. Both proposed projects have the potential for significant environmental benefits. However, due to the interdependent nature of the river system, they also have the potential to cause inadvertent adverse impacts on other water users and other environmentally sensitive areas. In addition, because the system ( and demands upon the system) are changing so rapidly, there is no baseline against which to measure the impacts. Thus the function of PROSIM is not only to estimate the project impacts, but also to provide a " yardstick" or " no- project" condition against which to compare them. In the development of this multidisciplinary EIS, the PROSIM model was used in a number of ways. First, the model was used to design project alternatives that produced acceptable water resources impacts. The PROSIM surface water model was linked and calibrated with a groundwater model of the potential water conservation impact area. Thus PROSIM calculates diversions, stream flows, and reservoir levels, while the MODFLOW finite difference groundwater model uses these results to simulate potential impacts upon groundwater levels and wetlands. The MODFLOW results for groundwater outflow are used by PROSIM as input to downstream surface water return flows. PROSIM was used to prepare specific hydrological information needed by EIS discipline leaders in their analysis of potential water quality, wetlands, aquatic resources, and threatened and endangered species impacts. 5.2 Providing Input on Water Supply Decisions PROSIM also is being used on an as- needed basis by CUWCD staff to analyze environmental, water supply planning, and operational decisions. Requests from agencies, companies, or individuals outside of CUWCD for simulation of a January 1998 Page 33 |
