Laserfiche WebLink
<br />2.3 Principal Flood Problems <br /> <br />Flooding along Tenmile and Meadow Creeks in Frisco normally occurs <br />from May through September. Floodwaters may result from snowmelt <br />and/or intense rainstorms. <br /> <br />Records of damages resulting from past floods were not available. <br />However, flows approximately equalling the computed 100-year <br />discharge were recorded on June 16, 1965, along Tenmile Creek. <br /> <br />2.4 Flood Protection Measures <br /> <br />No flood protection structures either exist or are proposed that <br />would reduce the flood hazards in the Town of Frisco. <br /> <br />3.0 ~NGINEERING METHODS <br /> <br />For the flooding sources studied in detail in the community, standard <br />hydrologic and hydraulic study methods were used to determine the flood <br />hazard data required for this study a Flood events of a magnitude which <br />are expected to be equalled or exceeded once on the average during any <br />10-, 50-, 100-, or 500-year period (recurrence interval) have been <br />selected as having special significance for flood plain management and <br />for flood insurance premium rates. These events, commonly termed the <br />10-, 50-, 100~, and 50 a-year floods, have a 10, 2, 1, and 0.2 percent <br />chance, respectively, of being equalled or exceeded during any year. <br />Although the recurrence interval represents the long term averaqe <br />period between floods of a specific magnitude, rare floods could occur <br />at short intervals or even within the same year. The risk of experiencing <br />a rare flood increases when periods greater than 1 year are considered. <br />For example, the risk of having a flood which equals or exceeds the <br />lOO-year flood (1 percent chance of annual occurrence) in any 50-year <br />period is approximately 40 percent (4 in 10), and, for any 90-year <br />period, the risk increases to approximately 60 percent (6 in 10). The <br />analyses reported here reflect flooding potentials based on conditions <br />existing in the community at the time of completion of this study. <br />Maps and flood elevations will be amended periodically to reflect <br />future changes. <br /> <br />3.1 Hydrologic Analyses <br /> <br />Hydrologic analyses were carried out to establish the peak discharge- <br />frequency relationships for floods of the selected recurrence <br />intervals for each stream studied in detail in the community. <br /> <br />Flood discharges for the 10-, 50-, 100-, and SOD-year recurrence <br />events on Tenmile Creek were calculated using regression equations <br />based on a regional analysis of all the gages within Summit County. <br />At each gaging station, the annual flood peaks due to snowmelt and <br /> <br />4 <br />