Drainage project may clog up traffic

The Sheppard Street off-ramp from U.S. Highway 17 was closed Monday and will remain closed while construction crews install a 125-foot-deep shaft. Charleston has begun construction on phase two of the Septima P. Clark Parkway drainage project.

The Septima P. Clark Parkway’s notorious flooding stops traffic crossing the peninsula, and an ambitious plan to fix it will cause some new, albeit temporary, frustrations for commuters.

The city of Charleston on Monday began work on the second of five phases of the $154 million project, which will require detours and closures over the next two years, said Steve Kirk, the city’s senior engineering project manager.

The parkway regularly floods during heavy rain and high tides, with water sometime rising higher than the bumpers of cars.

The first of those closures for the parkway, which also is known as the Crosstown, began Monday.

They will last about two months and will affect drivers coming onto the peninsula from East Cooper, across the Arthur Ravenel Jr. Bridge or from Interstate 26 East. Drivers coming from U.S. Highway 17 North in West Ashley will be spared in this round of closures, in which the city will close the Sheppard Street off-ramp from the expressway to Rutledge Avenue, as well as that section of Sheppard Street.

Also, the intersection of President and Fishburne streets will be closed for utility work associated with the project.

Kirk said drivers who usually drive on Sheppard Street should use King Street or Rutledge Avenue to travel north and south on the peninsula. For other alternative routes, drivers should refer to a map on the project’s website, www.septimaclarkproject.com.

Kirk also said he doesn’t think the detours will cause severe traffic disruptions. “It’s going to take folks a few days to get used to the patterns, but once they do, I think everything will fall into place.”

The city did all it could to help alert drivers about the changes in advance, he said. It sent alerts and maps of alternative routes to many peninsula groups and employers, he said.

The Medical University of South Carolina on Friday emailed the information to all of its employees, spokesman Tony Ciuffo said.

Kirk said there will be traffic diversions throughout phase 2, which will last about two years and cost $23.5 million to build. The city will announce the closures in advance, he said.

Each set of closures likely will last about two months, he said, and disruption to traffic will be less than in the project’s first phase.

That phase included improvements to pedestrian and vehicular safety and some drainage work, as well as beautification work.

Phase 2 includes drilling eight shafts that range from 120 to 154 feet deep. Three of them will be 48 inches in diameter and five of them will be 54 inches. Six of those shafts will be dug along the Crosstown’s current route, between Coming Street and the Ashley River. The other two will be dug along President Street, between Harmon Field and Cannon Street.

The next phase involves digging the tunnel to which the shafts will connect, Kirk said. “Folks will feel very little effect from that,” he said.

Phases 4 and 5 involve constructing a “wet well” for large stormwater pumps and then building a pump station at the Ashley River, Kirk said.

The project should be complete in 2020.

Reach Diane Knich at 937-5491 or on Twitter at @dianeknich.