The lead engineer that studied the Church Creek drainage basin this year will tell Charleston City Council on Monday there's no singular solution to the area's flooding problems.
Instead, Bob Horner of Weston & Sampson Engineering will lay out a variety of options the city can pursue based on how much it can spend and the outcomes it wants to achieve.
"What you’re not going to see is, 'Here’s your magic bullet, go and do this, and everything will be fine,'" said Josh Martin, adviser to Mayor John Tecklenburg. "We have a lot of good choices on how to move forward, we just have to stick with one we think we can execute."
Council will also be asked to consider extending the building moratorium in the area for another six months. It was originally set for nine months in February after area residents demanded answers on why their homes had been repeatedly flooded over the past few years during major storms.
Martin said the extra break from development will give council and the public time to consider Weston & Sampson's recommendations. Another public presentation will be held at 6:30 p.m. Thursday at West Ashley High School.
For about five months, Weston & Sampson Engineering has studied the area and used modeling technology to understand how water moves through the basin during different types of weather events.
The basin spans about 5,000 acres in the northwestern corner of West Ashley, and includes neighborhoods such as Shadowmoss, Hickory Hill and Bridge Pointe.
The diagnosis showed the drainage system's main flaw is that it's designed to rely on Church Creek, a 10-foot-wide channel, to drain most of the area's runoff to the Ashley River.
"Church Creek just does not have that kind of capacity," Horner said. "The issue is the basin is very, very large. It’s much larger than we anticipated. It extends farther into the undeveloped areas than I think anybody thought. And it’s very, very flat."
More land there has been developed and paved, and changing weather patterns have sent more frequent storms to Charleston's coast — making a bad drainage system worse, Horner said.
Weston & Sampson will recommend some policy changes, such as higher elevation standards for new structures. It also will encourage council to consider capital projects, such as a large pump station on Church Creek near Bees Ferry Road.
Horner said tests showed that would be particularly effective at reducing flooding from storm surge.
Another strategy already in the works is to remove repeatedly flooded properties from flood-prone areas altogether. The federal government is awarding the city of Charleston more than $10 million in grants to help buy 48 flood-prone properties in West Ashley. Many are in the Church Creek area, including all 32 town homes in Bridge Pointe.
"A possible expansion of that strategy might be a long-range recommendation to pursue," Horner said.