Floodplain%20Delineation%20of%20Unsteady%20Flow%20Using%20HEC-RAS

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Floodplain Delineation of Unsteady Flow Using
HEC-RAS

• Progress Report
• Presented By Kevin Donnelly

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Study Area

• The Colorado River between Wirtz Dam and Inks Dam
  (Lake LBJ) and its two major tributaries, Sandy
  Creek and the Llano River
• Lake LBJ is 21.15 miles long and 10,800 feet wide
  at its widest point. The lake covers 6,375
  acres, and its capacity is 138,500 acre-feet.

Inks Dam
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Objectives

• Develop a terrain model combining 30-meter DEM
  data, 2-foot contours, and UNET cross sections
• Develop new cross sections along the Colorado
  River (Lake LBJ), Llano River, and Sandy Creek
  using GeoRAS
• Simulate flooding that occurred in November 2000
• Import resulting water surface profiles back into
  GIS were the spatial extent of the flooding can
  be better seen and understood

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Input Data
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Intermediate Data
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Results
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Questions