PYTHON COROPORATION EMPLOYEE David Simpson, right, climbs from a manhole at South and Washington streets Thursday while fellow worker Juan LaSalle steadies the ladder. The northbound section of Washington Street between South and Veto streets has been closed to traffic since Tuesday while Python and Riverside Construction employees restore an old drainage tunnel beneath the street.(The Vicksburg Post/C. TODD SHERMAN)

[05/03/02]Restoration of a drainage tunnel under Washington Street that has lasted without known major repairs since about 1880 has caused minimal traffic rerouting downtown.

The northbound lane of Washington Street between Veto and South streets was blocked Tuesday through Thursday, said foreman Tim Burrough of Riverside Construction, the project’s primary contractor. The lane in that block was to be open today but closed again Monday through Thursday while workers from Python Corporation of Slidell, La., spray concrete inside the last 417 feet of the 2,652-foot brick tunnel they have been working to restore since the second week in March, Python superintendent Boone Moody said.

The arched tunnel runs three to four feet underground from Veto Street to just south of Main Street and empties storm water into the Mississippi River, Burrough said. It is 11 feet high in most places but shortens to 4-foot-6 in some, Moody said.

“The mortar on the old bricks got loose,” Burrough said. “We’re trying to preserve it and keep the city from spending a lot of money to put a new drain in.”

The project, which city strategic planner Paul Rogers said will cost about $737,000, began around the second week in March, Moody said.

The concrete, a special blend called Gunite, is being mixed with sand above ground, pumped through one of eight manholes to the spraying point using compressed air and mixed with a separate, adjustable, flow of water there, said Moody, a 30-year veteran of the process.

The process is a quick and relatively unobtrusive way to make repairs in hard-to-reach places, Moody said. “You don’t have to disrupt the road,” Moody said of the process. “We can put (Gunite) upside down, overhead, whatever you need.”

Traffic on the street was blocked off for the first time during the project this week, Burrough said.

Three to four inches of Gunite, reinforced throughout with a layer of galvanized wire mesh, is being added to the tunnel to stop leaks that have developed in it, he said. Moody said the next step is to pressure-grout whatever ground washout the leaks may have caused that have led to sinkholes in that stretch of street, Moody said. Parts of the surface of that part of Washington Street are brick and have developed sinkholes, Burrough said.

The Gunite, also used in swimming pools, generally doesn’t begin to deteriorate for about 25 years, Moody said.

City public works director James T. “Bubba” Rainer said there had been only minor repairs to the arched tunnel since it was built.

“Whoever built this sewer … did a good job,” Moody said. “They knew what they were doing.”

Meanwhile Thursday, in a city residential neighborhood, county workers were pouring concrete to improve the area around the grate of a drain near MacArthur and Skipland drives. The concrete was to lessen the grass and debris that was being trapped in the grate, a worker said.

County employees also performed maintenance work with dirt around a separate drain about 15 yards away.

District 3 Supervisor Charles Selmon, the only Warren County supervisor whose entire district is within the city limits, said the work was an example of city-county cooperation. The city and county have cooperated since 1983 to obtain

$6.6 million in funding from a federal environmental program for projects within the other’s jurisdiction, Selmon said. The $11,000 funding the county government has obtained for the MacArthur repair project was first approved in 1991.