PORT TOWNSEND — A mandatory water conservation notice has been issued by the City of Port Townsend to all city water customers after a leak was discovered in the main transmission line.

Steve King, the city’s public works director, said Thursday the leak appears to be fixed, but the conservation notice will remain in place for the next few days.

“The City Lake reservoir is about a 140 million-gallon reservoir, and we estimate we used about 40 million gallons to supply water while the pipe was being fixed,” King said.

Conservation measures will allow for the reservoir to be refilled at a pace of about 3 million to 4 million gallons per day, King said. The city plans to monitor the system for the next three to four days, he added.

The city shut down its transmission line from the Olympic Gravity Water System on Tuesday, King said.

It shifted to the City Lake reservoir, which can provide water for a minimum of five days under normal operations, the city said in a press release.

During the summer, the city uses about 2 million gallons per day, King said. The Port Townsend Paper Corporation uses about 11 million gallons per day.

The city and the mill worked under the terms of the water use agreement to repair the leak, the press release said.

The leak, in a steep and difficult-to-access location, came from a cracked fitting, which was discharging more than 500,000 gallons of water per day, King said.

“It was one of the air valves,” he said. “It turned out to be a pretty easy repair, but you never know until you get up there and shut the water off.”

The leak eroded soil near the transmission line on the hillside near Snow Creek. Property owners along the affected area of the pipeline are being notified, and city staff are coordinating with regional and state agencies, the press release said.

“It was in a very remote area,” King said. “We don’t know how long the leak was going. We’re digging into that, trying to figure it out.”

Once the transmission line is functional, additional assessment for soil and pipeline stability near the leak will be addressed for long-term stability of the system, according to the press release.

The conservation notice includes several steps that water customers can take, including reducing outdoor water use for irrigation, taking shorter showers, operating dish and clothes washers only when full, and fixing leaky faucets and/or toilets.

Water customers will be notified when the repairs are complete and the mandatory conservation measures are canceled, the press release said.

Port Townsend’s water is supplied by the Big Quilcene and Little Quilcene rivers via a 30-mile pipeline. The system has been in place since 1928, making it one of the oldest water systems in the state.