Drew Valley Detention Pond

Working With FEMA to Mitigate Future Flood Damage

DeKalb County, Georgia

New detention pond provides safer environment for residents of a DeKalb County subdivision, while keeping the area aesthetically pleasing.

A watershed assessment led to the development of a flood mitigation plan after a 2003 flood swept through the Drew Valley subdivision.

The detention pond saved the community nearly $1.5 million just months after it was completed.

After serious flooding in 2003 damaged a local DeKalb County, Georgia, neighborhood, the Drew Valley Subdivision was in need of a permanent flood mitigation solution. We partnered with Golder to conduct a watershed assessment of the flood and developed a plan that would ultimately lead to flood mitigation.

7

day approval process from Georgia Emergency Mangaement Agency and FEMA Region IV

$1.5 million

in losses avoided

1.6

acres of restored floodplain wetland

This resulted in capital improvement plans for upgrades to six culverts and the design of a regional stormwater management facility. Subsequently, DeKalb County applied for and received Federal Emergency Management Agency (FEMA) Pre-Disaster Mitigation (PDM) grants covering nearly 75 percent of necessary home buy-outs, as well as the final design and construction of the detention facility and culvert improvements.

The team designed, permitted, and provided construction oversight for the regional stormwater management facility, which reduces flooding and provides channel protection benefits in the Drew Valley Subdivision. The facility contains 1.6 acres of restored floodplain wetland, 325 linear feet of daylighted stream, and a concrete retaining wall dam and spillway. Construction was completed just five months before another severe flood in September of 2009, which saved the community $1.5 million in avoided flood losses.

Cost

$168,000

Services

Engineering
Environmental
Planning, Consulting and Advisory

Markets

Water

Regions

Southeast

703.849.0100