In San Francisco, about 50 yards due east of the Stow Lake boathouse, where Golden Gate Park visitors rent rowboats by the hour or have lunch by the water’s edge, stands a hulking electrical generator roaring behind a ramshackle fence.

The generator, mustard-yellow and more than 6 feet tall, has been whirring away all day, every day for more than a year, sending diesel fumes into the surrounding trees and obliging groups of passersby to huddle closely together to hear one another over the raw noise.

It was supposed to be a temporary fix after an aged underground electrical line supplying power to the boathouse and other nearby park facilities failed in late 2016. But a protracted squabble between the city and Pacific Gas & Electric Co. over who owns the power line — and who’s responsible for fixing it — means the generator will be running uninterrupted for the foreseeable future.

“There is a dispute between PG&E and the city ... regarding ownership of the lines,” said Connie Chan, a spokeswoman for the San Francisco Recreation and Park Department. That dispute will have to be resolved, she said, “before we can move forward repairing the power lines.” Last year, running the generator cost the park department about $77,000 in fuel and maintenance, Chan said.

“To resolve this dispute and find the best solution moving forward, we defer to the San Francisco Public Utilities Commission, our city’s leading agency on power-related regulatory issues,” she added.

Answering the central question in the dispute — who bears responsibility for fixing the broken electrical line — is difficult because of how old the cable is, according to Tyler Gamble, a spokesman for the SFPUC. Neither the city nor PG&E have definitive records to show who owns it.

“There is no paperwork that definitively states that,” Gamble said.

The deadlock between the city and PG&E has a familiar ring to it. In April, city and state officials sharply criticized the utility for extensive delays in supplying power to three city-owned locations, including a children’s museum in Corona Heights, a homeless shelter in Dogpatch, and the Noe Valley Town Square.

The lights were eventually turned on at the museum and shelter after then-Mayor Ed Lee brokered a deal between the city and PG&E. Noe Valley Town Square also ended up being powered, without the need for the mayor’s office to intervene, though former Supervisor Scott Wiener insisted to PG&E that it power that site.

Some accused PG&E of purposely procrastinating as it competes with CleanPowerSF — the green energy initiative being rolled out by the SFPUC that’s siphoning customers from the utility. CleanPowerSF’s energy comes primarily from renewable sources, but it still relies on transmission lines and other infrastructure owned by PG&E. The Stow Lake boathouse had been running on power generated by the SFPUC, but sent through PG&E’s transmission lines.

“PG&E doesn’t feel any sense of urgency in resolving these issues, especially when they involve hooking up power to some city facilities,” said Supervisor Jeff Sheehy. “It’s happened before.”

PG&E denied employing delay tactics last year, instead blaming the SFPUC for failing to provide information and submit certain payments in a timely manner.

When it comes to the Stow Lake generator, PG&E is adamant that the underground power line is owned by the city. The utility is willing to lay an entirely new cable, and run PG&E electricity through it, but that project would probably take months. Chan from the park department said PG&E estimated the job would cost around $1.5 million.

“After an electric cable failed, which is owned by San Francisco Recreation and Park, they requested PG&E install a new stretch of cable owned, operated and maintained by PG&E,” said Andrea Menniti, a spokeswoman for the utility.

“We’ve spent the past several months working together with San Francisco Recreation and Parks to ensure the Stow Lake boathouse project is moving forward safely and as quickly as possible,” Menniti said.

“We learned PG&E believes that the worn-out cable serving the Rec and Park facilities belongs to the city,” said Gamble from SFPUC. “We’re asking PG&E to provide its view on the ownership of the equipment in writing.” In the meantime, the agency has already begun drafting plans for diagnosing and repairing the broken power line, should PG&E confirm that the cable isn’t theirs.

Peter Akraboff rides his bike past the generator about three times a week. What’s frustrating for him isn’t the loud piece of machinery itself.

“It bothers me the way the piles of broken glass in the park and along the bike lane bother me. It’s a bit of noise and a bit of diesel smoke blowing through the trees, but it isn’t like any major disruption,” he said.

Rather, the generator to him is a frustrating symbol of the underlying dysfunction between the city and PG&E that’s kept the power lines from being fixed in the first place.

“It’s the idea that no one can seem to get it together to get this fixed,” Akraboff said. “Someone should pick up the ball and run with it.”

Dominic Fracassa is a San Francisco Chronicle staff writer. Email: dfracassa@sfchronicle.com Twitter: @dominicfracassa