Charleston installs ‘pocket wetlands’ in Church Creek to stem flooding | News

An area of ​​West Ashley plagued by flooding could see some relief after the City of Charleston installed a series of “pocket wetlands” to help with stormwater management.

The Charleston City Council approved a $246,000 construction contract on May 10 that will create ponds and a three-lot walking path on Mowler Court where a cluster of homes once stood. This is part of a larger $5.2 million effort to integrate these types of flood mitigation projects into Outer West Ashley.

The city has strategically purchased properties in the Shadowmoss neighborhood over the past few years. The neighborhood is part of the larger Church Creek Basin, a 5,000-acre expanse that is almost fully developed.

Councilor Stephen Bowden, who represents Outer West Ashley and lives in Shadowmoss, said the project was a long overdue addition to the area.

“These are sort of small plots of land, but I think we can use them to see what we can do in the future,” Bowden said. “I’m excited as someone who hopefully won’t have to rowboat every time we have a hurricane.”

Two other lots purchased by the City in the neighborhood will see drainage improvements in the coming months. On the surface, these lots will appear as rain gardens or low-lying green spaces preserved to absorb water. Below the surface, the city plans to extend and improve the existing drainage pipes.

“Every drop counts. If you have a drop of water somewhere in the basin that you hold on to for a while…it makes a difference to the whole basin,” said Charleston Mayor John Tecklenburg, at the Post and Courier.

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An intersection in Shadowmoss is flooded in the aftermath of Tropical Storm Irma in September 2017. The City of Charleston used federal grants to buy out properties in the area. File/Brad Nettles/Personal

Church Creek Troubles

Church Creek is the only stream connecting the drainage basin to the Ashley River, and it is only 10 feet wide. It always overflows easily in heavy rain, even before the first bulldozers arrive to change the landscape. But when the Federal Emergency Management Agency developed the first flood maps for this area of ​​West Ashley in the early 1980s, it didn’t take into account how the narrow creek behaves as it fills with rain. Like most maps of the region, FEMA only looked at storm surge flooding during a hurricane.

The agency also assumed that a railway running parallel to Bees Ferry Road would act as a barrier. In effect, it acted as a dam for water flowing in the other direction during heavy rain.

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Today, the Church Creek basin is about 80% developed, and residents believe the Bees Ferry Road expansion completed in 2014 has only worsened the flooding. Major storms in 2015, 2016 and 2017 caused widespread flooding.

The city has spent years researching the problems and potential solutions for the Church Creek watershed. A city consultant once even suggested buying up to 350 houses in the basin. According to the consultant, one of the major contributors to the flooding was fill soil used to build new homes.

The city updated the stormwater standards for the basin in response to this study, and in late 2021 commissioned a comprehensive new plan for the city that discourages development in low-lying areas while encouraging greater density in neighborhoods less prone to flooding. The plan asks the city to rewrite its zoning code accordingly.

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Homes along Cabrill Drive in West Ashley wind up to a pond near Church Creek. The City of Charleston purchased a cluster of homes near Mowler Court to use for stormwater retention sites and park space. File/Personal

Find solutions

The plan to create ‘pocket wetlands’ on the Mowler Court buyout properties is part of a wider strategy to return some of the developed land in the Church Creek basin to greenspace. The goal is to reduce the amount of developed land in the area to help absorb flood waters and provide recreational opportunities.

In West Ashley alone, at least three similar projects are underway.

Charleston first received a grant from FEMA to buy back a total of 48 homes in West Ashley in October 2017. Local governments are required to cover 25% of the cost of purchasing and demolishing frequently flooded homes.

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The site of now empty lots on Wolk Drive and Mowler Court in the Shadowmoss neighborhood will now become ‘pocket wetlands’ to help with stormwater management, pictured May 11, 2022 in Charleston. Grace Beahm Alford/Staff

The city bought out the Mowler Court properties and also bought 32 townhouses in a frequently flooded development called Bridgepointe. Authorities are finalizing plans for a park with stormwater management devices as well as a playground and picnic areas. The city council is expected to vote on this proposal by the end of the year.

The city is also considering vacant properties in the area and is in talks to purchase property next to the frequently flooded Crosstowne Church for a similar purpose.

For the two projects on Mowler Court, the Bridgepointe project and the crosstown church project, Charleston is contributing $3.6 million from the city’s drainage fund and just over $125,000 from the small water projects fund. storms. A remaining $1.5 million is funded by two grants from the National Fish and Wildlife Foundation.

Going forward, Tecklenburg said he wants the city to be able to direct more of its own funding to buyouts and similar projects rather than waiting for federal funds to become available.

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One source will be the Church Creek Tax Increment Financing District. The special tax district funnels tax money from the area to Church Creek. Unlike other TIF districts, funds raised within Church Creek TIF can only be used for flood mitigation. Now four years old, the TIF is almost at the point where it can issue bonds with its income, multiplying its purchasing power.

“The overall vision for the city is to protect against flooding but also provide recreational benefits at the same time,” Tecklenburg said.

Editor’s Note: This article has been updated to reflect the correct allocation of funding for each project in the Church Creek Basin.

Reach Emma Whalen at 843-708-5837. Follow her on Twitter @_emma_whalen.

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