To Infinity… Inlet Study and Beyond: How Thousands of Storm Drain Inlets were Analyzed to Support Stormwater Planning and Flood Mitigation within the City of Alexandria
Two of the City of Alexandria’s largest watersheds have almost 4,000 storm drain inlets. Undersized or inefficient inlets can lead to flooding issues in urban areas, even if connecting storm drain system has sufficient capacity. This presentation will share how field investigations and desktop analysis, coupled with an AECOM-developed calculation tool, were used to rapidly evaluate and analyze the City’s storm drain inlets. These existing inlets were evaluated based on three key metrics: inlet spread, gutter depth and bypass flows to recommend proposed new and upsized inlet locations to provide flood relief. AECOM developed and leveraged the power of coding to provide an efficient tool that drastically reduced the inlet calculation time for a storm drain network from days to seconds, allowing changes and iterations to be almost instant. The results from this project provided the City with a better understanding of potential inlet issues and locations that could be upgraded as the City continues to focus on flood mitigation as part of their Flood Action Alexandria initiative. The City can now use this data in grant applications and in their continued effort to support other infrastructure improvement projects. This type of analysis and evaluation could benefit municipalities looking to have a better understanding of their storm drain inlet performance, to provide flood relief and increase safety for their community.
Author Bio
Greg has more than 12 years' experience in civil/water resources engineering and is currently registered as a PE in MD & VA, a Certified Floodplain Manager with a BS in Civil Engineering from Virginia Tech. His has worked for federal, private and public clients on floodplain studies, flood mitigation, land development stormwater management and storm drain infrastructure designs. Brian has more than 20-years’ experience in both private and public arenas as a practicing Civil Engineer. Brian is currently a registered PE in VA, a Certified Floodplain Manager, with a BS in Civil/Environmental Engineering from Seattle University. For the last 12-years at the City of Alexandria, Brian has managed development in FEMA flood zones, stormwater infrastructure planning, contract management for professional services consulting and construction contracts, and remote sensing program for rain gauges and stream gauges. He is the City’s Floodplain Manager and FEMA CRS Coordinator.
