One of downtown Charleston's worst flooding problems will get some attention soon, as the U.S. Department of Transportation gave the city $10 million to begin work on the Crosstown Expressway.

Improvements to the six-lane highway, also known as U.S. Highway 17 and the Septima Clark Parkway, could begin later this year.

Mayor Joe Riley visited Washington on Wednesday to seal the deal, calling it an important step toward a comprehensive drainage solution. He said he hopes to present a construction contract to City Council by Thanksgiving.

The work will include new curbs and gutters and improving the roadbed, which was built partly atop filled-in creeks and has settled unevenly.

Riley said those steps will ensure that the road drains better during normal rains, but the road will continue to flood occasionally until the city finishes its planned $146 million West Side drainage project.

The upcoming $12 million project, which includes $2 million in city money, also will give the six-lane highway a new look.

Riley said the lanes will be narrowed enough to create a median landscaped with narrow trees and other plantings.

"It will be a tremendous transformation of the road visually," he said. The job also includes sidewalk upgrades and better street lighting.

The $10 million federal grant comes from the $787 billion stimulus bill that President Barack Obama and Congress passed last year.

The city had sought the full $146.3 million to complete its West Side drainage upgrade. While that bid fell short, the city received one of only 51 grant awards, beating out more than 1,300 competing projects.

Riley said the city hopes to secure a $25 million grant next year to make similar road improvements on western Spring Street and President Street, the second phase of the three-phase construction schedule.

And the city is continuing to look for funding sources to pay for the final and costliest phase, which involves building a network of 130-foot-deep tunnels and huge pumps to drain the 500 acres around the Crosstown.