Westwood Hydrology and Hydraulic Floodplain Modeling
Greeley and Hansen, A TYLin Company, partnered with the County of Henrico in developing a study and hydrology and hydraulic model to site a pump station outside the 100-year floodplain.
This project determined the feasibility of locating the Sanitary Pump Station (SPS) on the Porter Property located between the two highways and the interstate. The goal is to see if the site is feasible for the pump station to be located outside the 100-year and provide an updated analysis approvable by DPW. This property is affected by the Unnamed Tributary to Jordan’s Branch Tributary 1 and is within the Henrico County 100-year floodplain. This property is FEMA Zone X – Area of Minimum Flood Risk and Non-Special Flood Hazard Area, therefore, no FEMA review and permitting is required.
To assess feasibility of locating the SPS outside the 100-year floodplain on this property and plan for resiliency against the 500-year event, floodplain modeling and analysis will be required to confirm the 100-year and 500-year floodplain elevations and extents. The project team’s approach included reviewing available hydraulic analyses and recreating the HEC-RAS model to provide an updated floodplain modeling and analysis. This project also included Resilience Plan for the SPS with a recommendation to establish the electrical floor elevation above grade to protect the station from the 500-year flood.
Project Highlights:
- Floodplain management
- Hydrology and hydraulic study and analysis
- Proactive local agency coordination
- HEC-RAS modeling