Crosstown Drainage: What's been done, what's still to come

By Valencia

CHARLESTON, S.C. (WCIV) - Wading through flood waters has been a problem for the Holy City since its founding. For the first time in Charleston's history, city officials are one step closer to blocking the stream of storm water.

"Really what we are doing for the first time in the city's history is coming up with a new engineering and construction method to permanently handle the storm water," said Charleston Mayor Joe Riley.

From the beginning, Charleston's drainage problem was a unique one to tackle.

"About 60-80 feet below ground we have what is a Cooper Marl, which is a very stiff clay, which is very good for tunneling," said Steve Kirk, senior engineering project manager. "On top of that we have surficial deposits, sands, pluff mud that you see, [which is] not very good for tunneling at all."

A year ago, the first phase of the Crosstown drainage project dug through the layers and found a solution.

"We put over a mile of big pipes underground, replacing tiny pipes that were put years ago that weren't working and weren't designed well," said Riley.

One of the most recognizable changes in the Crosstown was traffic flow.

"Phase one of this project had the installation of an intelligent transportation system," said Kirk. "Cameras, other sensors that would keep an eye on traffic and help keep it flowing smoothly."

Now, construction workers are wrapping up phase 1 and phase 2 is set begin sometime in June or July.

For phase 2, Kirk says the work will flow off the Septima Clark parkway and onto President, Fishburne and Ashley streets putting in pipes and drainage structures.

Kirk says the project will cover about one-fifth of the peninsula.

"It's a lot of area that needs to be drained and therefore it's a lot of storm water that needs to collected and then conveyed quickly and efficiently in the streets through a tunnel system," said Kirk.

Phase 2 of the Crosstown project will install underground diesel engines that would pump 120,000 gallons of water per minute. The technology is much like that used in cities like New Orleans.

"We actually took a few field trips down there to look at their pump stations to see what they do, to see how they overcome their challenges," said Kirk.

While officials say the project won't be complete for another eight years or so, Riley says he hopes people can be patient throughout the progress.

"I think if we look in the fullness of time and understand that it's going to dramatically change the way the city operates," said Riley. "Things can't happen over night."

The overall project will cost $154 million. Phase 2 alone will cost about $17 million. The city of Charleston will begin making bids for contractors in mid-March.