City working to eliminate flood-prone areas

By Cindy Landrum  

SEPTEMBER 20, 2010 11:05 a.m. (0)

When a big rain is forecast in Greenville, the owners of a home on Wembley Road erect three big metal “cattle gates” across their driveway.

If they don’t, Gower Creek overpowers a culvert, rushes over the street and down the Chastains’ driveway toward their house like a mini waterfall.

A neighbor across the street had to remove the doors and windows on one side of their house because floodwater would come in after a heavy rain.

The Henderson basin, of which Wembley and Henderson roads are a part, is one of two areas in Greenville which the Federal Emergency Management Agency has said has homes with multiple flood loss claims, said Jessica Chapman, the city’s assistant engineer. The other is on Richland Creek over Bennett Street, Mohawk Drive and Chick Springs Road.

The problem is when the culverts were installed in those areas, they were undersized, said Mike Murphy, the city’s public works director.

Now, the city is in the middle of a project to fix that.

Culverts have been replaced on Bennett, Mohawk and Chick Springs and projects to do the same on Henderson, Wembley and Cleveland Street Extension are planned for the next year.

“This is not a 100 percent fix,” Murphy said. “There’s just not enough money to make a city flood-proof. If we get a 50- or 100-year event, we’re still going to have some flooding.”

But the city is trying to eliminate as much of the problem as it can in the Henderson basin, which is between Laurens Road and Pleasantburg Drive, and Richland Creek.

All but one of the seven culverts which have been or will be replaced are designed to handle 100-year storm events, Chapman said. Greenville has not had a 100-year flood since FEMA started keeping flood records.

A 100-year flood would occur if 9 inches of rain fell in a 24-hour period.

The Reedy River and downtown Greenville flooded in 2004 during a 50-year flood.

The other culvert could only be built to handle a 25-year flood because of the elevation of the land, she said.

Design work is underway for the projects, each of which will take three months to complete, said Dwayne Cooper, interim city engineer.

Construction is expected to start on the first crossing by the end of the year. The crossings downstream will be done first and then workers will progress up the river.

“We’re seeing the same ones flooding. When we go in to replace a crossing, homeowners tell us about a storm 10 years ago or 20 years ago,” Cooper said.

Part of the problem is older developments were not under the same storm water storage regulations as developments are today, Cooper said.

Much of the water comes from upstream and outside the city limits.

“Storm water knows no boundary,” said Greenville City Manager John Castile.

The city is working with FEMA to update flood maps, most of which are based on 1977 studies, Chapman said.

“The city has changed a lot since then,” she said.