SWAMPSCOTT – A project to repair the water main along Humphrey Street, Salem Street, Roy Street and Melvin Avenue has been delayed a week due to cold weather forecasts and scheduling conflicts, Public Works Director Gino Cresta Jr. said Monday.Water service for up to 200 homes will be “minimally disrupted” as the public works department switches the homes to a temporary water main.Unfortunately, he said, this temporary main is above ground rather than buried.”Before we dig, we have to hook up the temporary main,” Cresta said. “But it’s not insulated by four feet of soil, it’s above ground.”With the National Weather Service predicting nighttime temperatures dipping to the mid 30s, Cresta said that they decided to postpone the project a week. He added that unexpected scheduling conflicts on the part of contractors made the decision easier.The work is part of a 10-year, $5.6 million effort to upgrade the town’s main water lines. This phase of the project will complete the upgrade of the transmission pipe running beneath Humphrey Street from the Lynn to Marblehead town lines and the pipe underneath Salem Street.The project is funded by a no-interest loan from the Massachusetts Water Resources Authority, which has been divided among 10 years beginning in 2003, according to Town Treasurer Denise Dembkoski.