November 16, Ryan Bean. Brett Harrelson. Annie Smith. Brittany Wood

Transcription

1 CE 485/585 Erosion Control November 16, 2010 Ryan Bean Brett Harrelson Annie Smith Brittany Wood Table of Contents

2 Table of Contents 1 Project Scope.2 Flood Plain Maps.2 Flood Plain Resections.3 Win TR 55 Calculations 3 Appendix 4 Project Scope

3 This project is located in the Cherokee Hills neighborhood located in Tuscaloosa, Alabama. The Cherokee Lake was drained in 2005 and is causing flood problems in the neighborhood. This report includes the flood plain maps and information on the cross sections of the flood area. Flood Plain Maps The flood plain maps were recovered from the City Office of Engineers (COE) for the city of Tuscaloosa. The maps were delivered in a PDF format making it difficult to analyze using mapping programs such as ARC Map or AutoCAD. Instead the maps were scaled up and printed using a Hewitt Packard Plotter. Measurements and analysis of the map was then completed using engineer s scales to estimate distances in the flood plain. The site resides primarily in the AE zone that includes the normal channel area and the additional land that must remain free of encroachments to maintain the expected levels of a 100 year return period storm. Additionally, much of the site is included in the Special Flood Hazard Area (SFHA) also included in the AE zone. For the purposes of calculating storm potential correctly all surface cross sections were based on the SFHA levels. Flood Plain Cross Sections

4 The cross sectional lengths were assumed using the maps scale bar and an engineer s scale. Measurements were taken at each elevation for the entire channel including the two ponds located in Sub Catchment s 1 and 2. These values were then averaged based on their sub catchment zone for use in WINTR 55 WinTR 55 Calculations The flood plain was analyzed in WinTr 55 to get the flows during a flood. The picture below shows the hydrograph for all three reaches during a 100 year flood. The flood plain was analyzed by measuring the widths of each reach during a 100 year flood and using that number as the bottom width of the reach. Next the structures were entered using the acres of the lake and the weir length at the outlet. A three foot weir was the smallest weir that would work in the program. Any smaller than that and the storage capacity was no enough in the lakes to handle the water. The final flow at the outlet was 3280cfs and with the correct plan this water can be handled.

5 Appendix Lakes Lake project Tuscaloosa County, Alabama Hydrograph Peak/Peak Time Table (Trial #1) Sub Area Peak Flow and Peak Time by Rainfall Return Period or Reach ANALYSIS: 100 Yr Identifier (cfs) (cfs) SUBAREAS s S S REACHES R Down R Down R Down

6 OUTLET us Lakes Lake Project Tuscaloosa County, Alabama Hydrograph Peak/Peak Time Table (Trial #2) Sub Area Peak Flow and Peak Time by Rainfall Return Period or Reach 25 Yr 100 Yr Identifier (cfs) (cfs) SUBAREAS s S S REACHES R Down R Down R Down OUTLET

7 us Lakes Lake Project Tuscaloosa County, Alabama Hydrograph Peak/Peak Time Table (Trial #3) Sub Area Peak Flow and Peak Time by Rainfall Return Period or Reach 25 Yr 100 Yr Identifier (cfs) (cfs) SUBAREAS s S S REACHES R Down R Down R Down OUTLET

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