Laserfiche WebLink
~• <br />This task will complement similar work on baseflow conducted in 2005-2006 on a Iimited portion <br />of the main stem (from Denver to the Kersey gage near Greeley) by the USGS. The current task <br />will compute monthly gain/loss for the entire study period 1950-2002 and will cover the entire <br />mainstem and tributaries included in the alluvial groundwater model under Tasks 48 and 50. The <br />results of this task will be used to help calibrate the alluvial groundwater model being developed <br />under Task 48 by comparing the computed to simulated groundwater gain loss in a given reach <br />and time period. In addition, the results of this task will provide a useful addition to the <br />understanding of the South Platte River surface water -groundwater system. <br />Approach: <br />• Stream gain/loss estimates will be determined for up to 7 reaches along the South Platte River <br />and two tributaries located within the study area. The reaches over which gain/loss estimates <br />are to be determined will be finalized after review of available flow data presented in the <br />SPDSS Task 2 Technical Memorandum (LRCE, 2004) and related discussions with the <br />CU/Water Balance Contractor, and after review of the USGS baseflow results that are being <br />conducted for the Denver to Henderson reach of the South Platte River. <br />• Based on an initial review of SPDSS Task 2 and the stream gage records available, the <br />following stream gages are expected to <br />• e used to define the reaches, listed from upstream to downstream. The combined listing of <br />gages, below, on the South Platte at Waterton and on Plum Creek near Louviers is a situation <br />where the combined flow from both gages will be used to represent the inflow at the upstream <br />reach of the main stem of the South Platte just below the confluence of Plum Creek. The case <br />of two gages listed along the South Platte (near Balzac and at Cooper Bridge) represents a <br />change in the gage location and subsequent discontinuation ofthe Balzac gage: <br />• Cherry Creek near Franktown <br />• Cherry Creek at Denver <br />• South Platte at Waterton and Plum Creek near Louviers <br />• South Platte at Denver <br />• South Platte at Henderson <br />• South Platte at Ft Lupton <br />• Cache La Poudre near Fort Collins <br />• Cache La Poudre near Greeley <br />• South Platter near Kersey <br />• South Platte near Weldona <br />• South Platte near Balzac and South Platte at Cooper Bridge <br />SPDSS_Phase4_gw_SOW_09-15-06.doc tl <br />