Consulting

GCE provided engineering services for preparing the Sub-Regional Detention Drainage Plan for the City of Pearland (the City). The project was to conduct a Sub-Regional Detention drainage plan to provide recommendations for the improvements necessary to meet the City’s growth and future needs.

GCE conducted the drainage study for the Clear Creek and Hickory Slough Watersheds which comprised of approx. 197 square miles in area. GCE’s work included;

• 1. Identifying areas that needed to be updated in the existing hydraulic models for the Clear Creek and Hickory Slough Watersheds,
  
  
• 2. Incorporating the new developments or other information in the existing hydrologic/hydraulic models,
  
  
• 3. Identifying areas that have been annexed by the City and any areas that are planned for annexation in the near term and incorporating in the hydrologic and hydraulic models,
  
  
• 4. Determination of flooding and drainage problem areas from the initial data collection for the Clear Creek and Hickory Slough Watershed,
  
  
• 5. Assisting the City staff to identify tracts of land that are located in strategic locations within the watersheds to possibly serve as sub-regional detention sites, and,
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  6. Developing, analyzing, and costing of alternative conveyance improvements as well as sub-regional detention facilities.

GCE utilized ESRI's ArcMap 9.3 to identify watershed and sub watershed boundaries, to determine flow characteristics, to create a TIN and then coupling the TIN to perform HEC-RAS analysis. The results from HEC-RAS analyses were imported to ArcMap to delineate floodplain and floodway of Clear Creek and Hickory Slough. ArcMap was then used to prepare inundation maps for the watershed and to determine the distribution of flood depths for various flood frequencies. ArcMap was also utilized for identifying different type of land uses, and developed and undeveloped areas to estimate sub regional detention volume requirements. Finally, it was utilized to prepare exhibits for visual interpretation.

Work also included preparation of construction cost estimates and implementation plan for the feasible alternatives, evaluating benefits and costs and develop a recommendation on the CIP, preparing a full report for the Sub Regional Drainage Plan that identified the goals of the plan, the recommended sub regional program, recommended improvements and schedule, implementation schedule, funding options, timing of improvements based on the projected growth and recommended Capital Improvement Plan (CIP) for (COP). his report also served as an update to the previously prepared Master Drainage Plan.