FLOOD10387 ‎(2)‎

• County: Statewide
• Stream Name: Yampa River
• Title: Floodplain Information Report - Volume 1 - Yampa River from Craig to Dinosaur National Monument
• Date: 5/1/1995
• Prepared For: Recovery Implementation Program for Endangered Fish Species in the Upper Colo
• Prepared By: CWCB
• Floodplain - Doc Type: Floodplain Report/Masterplan

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methodology used for computing flood depths at the cross-sections is similar to accepted
methodologies used by state and federal agencies in performing detailed analyses, except that
there is no balancing of energy from one cross-section to the next.

The four surveyed cross-sections, the six surveyed cross-sections transferred to reaches other than
the reach where they were surveyed, and the two cross-sections that were. hybrids of map cross-
sections and field data are graphically represented in Figures 7A-M. Example rating curves were
prepared for the four field-surveyed cross-sections. They are presented in Plates 11-14, after the
floodplain maps.

4.5 Delineating Flood Boundaries

The calculated flood depths for the various stream reaches were first plotted on the quadrangle
maps at the cross-section locations. The resulting floodplain widths were compared to the
floodplain widths on the cross-section plots. The floodplain boundaries between the cross-
sections were then approximated by delineating flood depth contours and interpreting the
relationship between those flood depth contours and the ground contours. Consideration was
given to the slope within each reach. The fmalized information was displayed on the USGS 7.5'
quadrangle maps (scale of 1" = 2,000'). A table identifying the quadrangle maps used in each
plate and the map scale is given in Figure 8. The location of each floodplain map plate is shown
in Figure 9, and the floodplain maps are shown in Plates 1-10.

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