Laserfiche WebLink
<br />DRAF'~r <br /> <br />SECTION II - DETERMINATION OF FLOWS <br /> <br />INTRODUCTION <br /> <br />An extensive effort was undertaken to determine discharges <br />throughout the Master Plan Area. It involved the use of the most <br />recent data and procedures to develop discharges for the Blue <br />River, its major tributaries and local drainages within the Master <br />Plan Area. Three types of analysis were performed: a regional <br />frequency analysis to develop flows for the Blue River and its <br />larger tributaries, Army Corps of Engineers HEC-l modelling for <br />flows from the larger undeveloped areas of the tributaries, and use <br />of the SWMM model to estimate flows in urbanized areas. <br /> <br />Determination of discharges were made for the 2-, 5-, 10-, 25-, 50- <br />and 100-year events for each of the methodologies. <br /> <br />GENERAL BASIN CHARACTERISTICS <br /> <br />The major drainage basin that comprises the Master Plan Areas is <br />the Blue River. At the downstream most point of the MPA, just <br />upstream of its confluence with the Swan River, the Blue River has <br />a drainage area of 81 square miles. The highest point in the basin <br />is 14,265 feet MSL and the downstream boundary is at an elevation <br />of 9,200 feet MSL. <br /> <br />Due to the great difference in elevation, climatical <br />characteristics differ significantly throughout the ,watershed. <br />Average climatical data for Breckenridge adopted form the 1988 <br />Summit County statistical Abstract are listed in Table 2.1. The <br />mean annual temperature is 35' F. Over hal f the annual <br />precipitation occurs as snowfall. <br /> <br />TABLE 2.1 - BRECKENRIDGE CLIMATICAL DATA 1948 - 1986 <br /> <br />-------------------------------------------------------------------------------------------------------------- <br /> JAIl FEB lIAR APR HAY JUH JUL AUG SE. OCT NOV DEe ANNUAL <br />----------------------------------------------------~--------------------------------------------------------- <br />Monthly In, AVG 1.40 1.30 1.51 1.55 1.65 1.56 2.52 2.26 1.49 1.19 1.33 1.43 19.07 <br />Of Predp. MAX ' 3.97 3.31 2,96 2,93 3,15 4.20 6.21 6.73 3.74 3.59 3.22 4.85 26.59 <br /> MIN 0.51 0.16 0.29 0.39 0.24 0.06 0.11 0.56 0.12 0.05 0.21 0.35 13.66 <br />YEAR OF MAX 1969 1971 1980 1957 1973 1969 1974 1963 1961 1969 1979 1983 1969 <br />YEAR OF MIN 1966 1981 1966 1963 1963 1980 1978 1978 1956 1952 1963 19.f07 1960 <br />Monthly In, AVG 20.6 19.4 23.6 21.1 11.0 1.9 0,0 0,0 4,0 11.3 22.0 24.5 156.8 <br /> MAX 43.4 41.9 41.7 42.3 '5.3 16.1 1.0 1.0 53.0 64.5 49.0 94.1 288.3 <br /> MIN 3.0 2,1 4,0 3,5 0,0 0,0 0.0 0,0 0.0 0,0 7,2 4,5 91.9 <br />YEAR OF MAX 1957 19B6 19B3 1961 1983 1984 1949 197B 1961 1969 1979 1983 1983 <br />YEAR OF MIN 1966 1982 1962 1963 1963 1982 19B6 19B6 19B3 1962 19BO 1980 1963 <br />Great. Snow 40 4. 52 4. 24 5 0 0 1. 20 14 37 <br />Depth/Month in Inches <br /> <br />The topography surrounding Breckenridge is dominated by mountain <br />ranges. All the tributaries to the Blue River in the MPA, except <br /> <br />3 <br />