Brooker Engineering, PLLC has worked with Dewberry as a subconsultant to perform hydraulic and hydrologic analysis for 18 miles of watercourse in Schoharie County, New York. Dewberry is acting as the Study Contractor for the Federal Emergency Management Agency. The work is being performed on an indefinite delivery, indefinite quantity basis. Brooker receives task orders from Dewberry on funding is available from the Federal Emergency Management Agency.
Brooker uses ArcView GIS software to use LIDAR based survey data to compile floodplain workmaps. Cross sections are located on these maps and sent to the field crew for survey. The survey data is then incorporated into the terrain model to reflect underwater elevation model and bridge data. HEC-HMS for GIS is used to develop the hydraulic modeling. Flood profiles are generated for the 10-, 50-, 100-, and 500-year recurrence interval storm events. A floodway run based on one foot of equal conveyance encroachment for the 100-year flood event is determined. Coordination with local municipalities is performed to calibrate the hydraulic and hydrologic models to match observed high water marks. Peak discharges are calculated at specific locations based on FEMA guidelines and experience. The information is compiled into an updated county wide Flood Insurance Study.
Dewberry; Federal Emergency Management Agency