A century-old pipe that supplies water to a block of downtown businesses burst last Wednesday evening, forcing some restaurants and shops to shut their doors early.

Central Market chef/owner Tony Najiola reported the water main break as soon as he saw the water burst through the asphalt on Petaluma Boulevard, at about 5 p.m. on June 11. The pipe ruptured directly across from Central Market's front door, but the restaurant did not sustain any water damage.

"We had to shut out almost 60 customers that we would have served," said a disheartened Najiola. "It was a big deal."

Leonard Olive, operations manager for the city's public works and utilities department, said after the 4-inch cast iron pipe erupted between Western Avenue and B Street, traffic was diverted, streets were closed off and public works and utility crews both responded to the scene.

Unlike pipes that connect to an aqueduct, this channel delivered water to local tenants along Petaluma Boulevard. In order for work crews to fix the water main, water service was shut down for businesses surrounding that strip of the Boulevard.

Crews immediately began excavating to locate the leak, which required drilling multiple holes through the pavement before finding the source of the seepage. A temporary clamp was applied to the broken channel, and workers returned to the scene the next day to permanently fix the leak by removing 3- or 4-feet of the antiquated pipe and replacing it with a modern, plastic pipe.

Olive estimated the pipe was more than 100 years old, most likely built at the turn of the last century like the buildings above it. He speculated that the pipe could date back as far as the 1890s.

Central Market and neighboring businesses are back to business this week, as the city continues its efforts to replace sections of old pipe, especially on the west side of town.

Each year, Olive said significant sections of Petaluma's pipes are replaced as part of the city's Capital Improvement Plan, which includes work on sewer pipes, streets and sidewalks. According to the plan, the pipe that burst last week was scheduled for renovation in 2016.

"Every year we replace a little bit of the old pipe, so eventually everything has the modern materials that we utilize for pipes these days," Olive said.

Due to a lack of pipe erosion, Olive said it's likely the water main was only leaking as of Wednesday. Based on an analysis of the scene, he estimated hundreds or thousands of gallons of water was lost — not reaching into the millions thanks to the agility of the crews who responded.

"They caught it and got it isolated really quickly," Olive said. "Everyone knew exactly what to do."

(Contact Allison Jarrell at Allison.jarrell@arguscourier.com)