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- 2- . Recently retired Parks employee Kent Wiley worked closely with EDA W of Fort Collins and the CWCB on this five month $50,000 study to redesign the park and come up with comprehensive construction estimates and a suitable design alternatives. . The portion of the foot trail system closest to the reservoir was looked at for replacement also. . For the marina a design and layout is proposed that would be friendlier to fluctuation of reservoir levels. A channel in and out of the marina area would provide a more stable operation and better access to the reservoir for boats. Storal!.e Use Patterns Investil!.ation Study . The CWCB has completed a water use pattern study designed to determine if there is water user interest, how water users would use storage space, and if there is water fill this storage space. . The Waters Use Patterns Report is titled "Chatfield Reallocation Study Storage Use Patterns" completed by Brown and Caldwell in February 2003. This report can be found at http://www.cwcb.state.co.us/floodwatch/ChatfieldWeb-Current/reports.htm . Tills study showed 16 water providers had a viable interest in additional reservoir storage. . Four types of water storage use patterns were modeled (municipal, agricultural, environmental releases, and conjunctive use). . This study was based predominantly on Denver Water's PACSM model for reservoir operations and covered a period from the 1940-1990s. Report on Corps Hvdrolol!.v/Hvdraulics . Rick Miner stated that the Corps will prepare a report on its HEC-5 and HEC RAS models and the reservoir flood routing model for the reservoir's design flood spill way pools required by the Corps. . The Corps contracted Tetra Tech for the remainder of the study. The contract is for wildlife mitigation and environmental consultation, the Environmental Impact Statement, and completion of the reservoir reallocation feasibility study. The "Storage Use Patterns Study" and "Recreation Mitigation Study" results will be incorporated. . Rick Miner will produce a revised schedule, the previous schedule called for completion in December 31,2005. . A by-product of the modeling efforts is floodplain delineation study for the 10- Y ear and 100- Year flood events for the stream reach of Chatfield Reservoir along the South Platte River to the ColoradolNebraska state line. . Gary Lein strung together 8-9 HEC II models from FEMA PIS floodplain studies and Urban Drainage & Flood Control District data to create a seamless HEC-RAS model for the South Platte. . Bill Doan developed a HEC-5 Model for performing reservoir modeling analysis that included all three Corps flood control reservoirs (Chatfield, Cherry Creek, Bear Creek) using flood data and stream data from 1944-2000. Four primary gages for flooding impacts are Denver, Henderson, Kersey and Julesburg gages. . The Corps hydrology/modeling discovered that urbanization has affected gage data. The Corps accounted for urbanization by adjusting rain gage responses to newer rainfall/runoff values to get a run off response that reflects today's conditions. The Corps studies show that urbanization has created more water/runoff in the South Platte watershed over the last 30 years. . Gary T ,ein discussed how the hydrologic modeling and hydraulics analysis would he 1L,,,d tr> create economic impacts from flooding. The model considered different release discharges at the reservoir, stream gages and the corresponding water surface elevations. The Corps is using a Flood Protection. Water Project Planning and Finance. Stream and Lake Protection Water Supply Protection. Conservation Planning