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For the rema1.n1ng streams studied by detailed methods, the water- surface elevations of floods of the selected recurrence intervals ..ere computed using the COE HEC-2 step-backwater computer progrsm (Reference 21). For several streams previously studied by the UDFCD, the existing 10- and 100-year water-surface profiles were utilized to expand the UDFCD studies to conform with Flood Insurance Study Guidelines. An interpolation-extrapolation procedure was used to develop the 50- and 500-year water-surface elevations at each cross section. This procedure was based on the assumption that there is a linear relationship between the logarithm of stream discharge and the logarithm of water-surface elevation. Cross section da ta were obtained from various topographic maps. At some loc8t.ions, field-surveyed cross sections and improvement plans were used to supplement the topographic mapping. The var1QUS sources used to obtain cross section data are as follows: Base Map Source Hogan/Olhausen, Inc., Topographic Maps, Jefferson County (References 22 and 23) U.S. Geological Survey, 7.5-Minute Series Topographic Maps (References 24 and 25) Streams Covered Bear Creek (Kittredge to Evergreen)1 Bear Creek Tributary Number 1 Bear Creek Tributary Number 2 Bear Creek Tfibutary Number 3 Bergen Creek Buffalo Creek Cub Creek Elk Creek (At Pine) Little Cub Creek Myers Gulch North Fork South Platte Riverl North TurkiY Creek Pine Gulc~ Sand Draw Troublesome Creek Wilmot Creek Wilmot Creek Tributary Bear Creek (~ove Evergreen Lake)1 Big Dry Creek 1 Cold Spriyg Gulch Cub Creek 1 Elk Creek (Above Sphinx Park) Kerr Gulch 1 Swede Gulch Switzers Gulch 1 Van Bibber Creek 19