Laserfiche WebLink
<br />, I <br />I <br />: I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />II <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />4 <br /> <br />to the above reports. These Included the Bruchez correspondence file, topographic <br /> <br />maps, meetings with KevIn Stewart and William DeGroot of the UD&FCD and Randy <br /> <br /> <br />Case of the city of Westminster, and the various computer models and output devel- <br /> <br />oped during the 1986 stUdy. <br /> <br />HYDROLOGY <br /> <br /> <br />During a study's hydrologic phase, runoff hydrographs are developed which incor- <br /> <br /> <br />porate the runoff volumes and peak flow rates based on design rainfall input and <br /> <br /> <br />other physical variables anticipated for the ultimate development of the watershed. <br /> <br />Existing Hydrologic "odel <br /> <br /> <br />The hydrologic model used in this report was developed by Greiner Engineering for <br /> <br />their 1986 report. This model is based on current guidelines of the UD80FCD for <br /> <br /> <br />rainfall and hydrograph synthesis. Hydrographs for each subbasin were developed <br /> <br />using the Colorado Urban Hydrograph Procedure (CUHP) of the UD&FCD. These indivi- <br /> <br /> <br />dual hydrographs for each subbasin were then routed through the various channels <br /> <br /> <br />and combined using the HEC-l Flood Hydrograph Package of the U.S. Army Corps of <br /> <br />Engineers (USACE). <br /> <br />RaInfall. The rainfall used in the 1986 study utlllzed the current UD80FCD guide- <br /> <br /> <br />lines. The 10o-year rainfall event has a total depth of 3.08 inches distrIbuted over <br /> <br />a 2-hour perIod accordIng to the time distribution of raInfall contaIned In their <br /> <br /> <br />Storm Drainage Manual. A depth of 2.60 Inches of rain occurs In the first hour. <br />