| OCR Text |
Show Final Report Hydrologic Model Analysis of the Provo River Basin 4.0 ANALYSIS OF FLOWS, STORAGES, AND WATER SUPPLIES UNDER PROPOSED DEMANDS SCENARIO PL102- 575 directs the District to perform hydrologic analysis of the Provo River system under " proposed project demands/' This section describes the methods used to analyze the system under proposed demands and briefly presents the results of that analysis in terms of streamflows, reservoir levels, and water supplies throughout the system. 4.1 Description of Modeling Data and Assumptions The Provo River system was analyzed under proposed project demands using PROSIM. Two separate types of modeling conditions were developed to represent the Proposed Demands Scenario. These modeling conditions are the hydrological setting and the operational setting. Because the modeling conditions and assumptions directly affect the simulation results, the scenario setting must be fully understood in order to understand the results. The hydrological and operational settings are described briefly below. 4.1.1 Hydrological Setting The hydrological setting for the Proposed Demands Scenario includes all of the natural inflows, meteorology, land use, and return flow responses developed during the hydrologic analysis studies described in Sections 2.3 and 2.5. The hydrological data from the period 1950 through 1989 is used, along with future demands, operating rules, and facilities, to represent future conditions on the Provo River system. The only change to the hydrological setting involved adjustment of the return flow delay patterns associated with applied water in the Heber Valley. The Heber Valley return flow delays were adjusted as part of the environmental analysis conducted for the Wasatch County Water Efficiency Project ( WCWEP), another part of the CUPCA studies. Precise tracking of groundwater levels and the impacts associated with irrigation changes was required for WCWEP. The USGS's finite- difference groundwater model MODFLOW ( USGS, 1988) was applied to the Heber Valley. The Heber Valley return flow functions in PROSIM were calibrated to be consistent with MODFLOW output of return flow delay rates, volumes, and patterns. Additional discussion of this recalibration is provided in Thurin and White, 1995. 4.1.2 Operational Setting The operational setting used in modeling the Proposed Demands Scenario is complex. Only with a reliable computerized representation of the operational January 1998 Page 25 |
