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Flood Studies - Northeast
Pennsylvania, Maryland, and West Virginia
Preparation of flood studies in the Northeast, including flood sources in Virginia, West Virginia, Maryland, Delaware, Pennsylvania, and Washington, D.C. The scope of these flood studies was to perform hydrologic and hydraulic analyses to revise existing (effective) Flood Insurance Rate Maps (FIRM), in part as a result of implementation of mitigation projects such as improved channels, levees, floodwalls, and other flood control projects. Examples of projects are briefly described.
Flood Study, Mineral County, West Virginia The flooding source was Cabin Run. The study reach length was 7.0 miles downstream of a 40 feet high earth dam designed and built by the NRCS. The scope of the study was to perform hydrologic and hydraulic analyses and to map the Special Flood Hazard Area (SFHA). Regression models of the USGS were used in the hydrologic analysis and HEC-RAS model was used in the hydraulic analysis. Digital mapping of the 100- and 500- year floodplain was completed in accordance with FEMA's Flood Insurance Studies Guidelines and specifications for Study Contractors
Flood Study, Carroll Township, Pennsylvania. The purpose of this project was to revise the existing flood inundation boundary by incorporating new data for the Route 34 Bridge.
The flooding source was Sherman Creek. Because the existing WSPRO hydraulic model of Sherman Creek was not available, hydraulic analysis and the flood inundation boundary were made for the entire reach using current information obtained from the field. HEC-2 was developed. Cross-sections were obtained from the field and from the topo map, scale 1"=400 ft. An historical flood measured at the bridge was used to calibrate the hydraulic model.
Log Person Type III statiscal frequency analysis was performed using the gage data to come up with the Qn-year for this flood study. The gage is located at the bridge shown above.
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