Vicksburg officials were confident this morning about tonight’s shift of water service to the city’s reserve tanks while crews move the main water pipe.

Flow from the primary line is expected to be halted at 10 p.m. and remain off for about four hours, during which pressure isn’t expected to drop enough to trigger a precautionary boil notice, City of Vicksburg Public Works Director Bubba Rainer said.

“We don’t anticipate anyone noticing,” Rainer said. “We’re trying to keep people from panicking.”

Hemphill Construction was hired by the city in May to move the 36-inch main-supply pipe on Washington Street between Jackson and Grove streets following a land shift reported March 26 near the proposed museum and interpretive center at the MV Mississippi IV. Flow from the Water Treatment Plant via the pipe feeds the city’s 10,000 water customers.

As crews move the line, water coming through customers’ faucets will come from a 1.5 million-gallon reserve supply held in the city’s four water towers.

Customers shouldn’t lose pressure while a valve is inserted in the line, a move that contractors expect to be completed in five to six hours, Rainer said. If the job takes longer than four hours, boil notices would be issued by the city and would affect the city’s highest elevations first. A boil notice advises water customers to boil all drinking and cooking water vigorously for two minutes. If necessary, boil water notices will be announced via The Vicksburg Post, www.vicksburgpost.com, local cable Channel 23 and Vicksburg radio stations.

The U.S. Army Corps of Engineers has agreed to pay for the $1.36 million reroute, which involves a new, 30-inch pipe going around the shift site via Main, Walnut and Jackson streets. Connections there should occur in a week to 10 days without any interruption of water service from the plant, Rainer said.

Corps contractors have worked to finish the $16 million museum by 2011. Soil borings involved in the design of a retaining wall along Washington Street included in the project have been delayed until after the main water pipe is rerouted.

Stabilization and repaving parts of Washington Street near the museum are likely to follow the water emergency, Mayor Paul Winfield said, calling tonight’s work “the best alternative” to avoiding a “potentially disastrous situation.”

“Something needs to be put in place to ensure nothing like this will happen again,” Winfield said, adding a federal appropriation is the lone and likely avenue. “Those projects aren’t easy.”

A land shift was blamed for a two-day water outage in September 2006 when the main water pipe blew out near the Port of Vicksburg.