Ely Creek Backflow Prevention Project

Ely Creek, a human-altered stream in the northern section of the City of Lambertville, backfloods from the Delaware River when the river is high. Twenty-nine dwellings and five commercial structures were impacted by Delaware River floods in 2005 (75-year return event) and 2006 (60-year return event). The combined claims to the Federal Emergency Management Agency’s (FEMA) National Flood Insurance Program were $365,500 in this low lying area of the City. Residents were unable to reoccupy homes until utilities were repaired and replaced, and businesses were closed until carpeting, drywall, electric outlets and equipment were replaced. The Ely Creek basin has the worst commercial flooding in the City.

Working for the City, Princeton Hydro assembled data, modeled the watershed, performed a benefit-cost analysis, selected the components, performed preliminary and final engineering, submitted for permits, developed bid specifications, provided contractor oversight and administration of a FEMA $150,000 Flood Mitigation Assistance grant overseen by New Jersey Office of Emergency Management.

The project includes the installation of a flood gate (slide gate) to block creek backflow, and the utilization of portable pump to bypass the flow of Ely Creek to the Delaware River. The project required little infrastructure modification and takes advantage of the Delaware and Raritan Canal embankment in protecting the low land surrounding the creek.

For a fraction of the claims paid by FEMA, residential dwellings and commercial properties are now protected from Delaware River backflooding via Ely Creek for storms similar to those of 2005 and 2006.