In all, 3.5 million gallons of San Francisco water leaked into the bay from broken pipes on Pier 15, home of the Baydelta tugboats.
"In some cases, there was close to 1 million gallons in a month's time that was lost," Public Utilities Commission spokesperson Tyrone Jue said.
The massive leak, which started in September, finally stopped last week when the Port of San Francisco shut off the water lines to the pier.
The city PUC discovered the leak at the end of September during a routine meter read.
The port, which is responsible for maintaining the pipes on the wharf, tried unsuccessfully twice -- once in October and again in December -- to close the leak.
Last week, ABC7 told the PUC, based on information from a source, that water was still leaking.
A surprised port spokesperson said they do not know who turned the water back on.
"It's an unknown third party at this point and we're looking into it," Renee Dunn Martin said.
Crews have now placed locks on the water valves.
Jue says the wharf's aging pipes, like the ones under Pier 15, are starting to crumble.
"You can apply the Band-Aid so many times to fix pipes but eventually, you're going to have to invest major money to replace them," he said.
The port has a 10 year capital plan to upgrade its infrastructure, which includes replacing the old pipes.
But most of that work and maintenance have been delayed.
"It takes a lot of money to repair them and it takes a lot of staff that we just don't have," Martin said.
The PUC says it will start installing automated water meters on the wharf this spring, which should detect leaks the moment they happen.
The port says its crews are still waiting to make emergency repairs on Pier 15's rotting pipes that caused the leaks.
"You don't get many of those days when the tide and the weather cooperate but we're crossing our fingers we can get it done in the next week or so," Martin said.
The PUC is still trying to figure out how much money was lost from the multi-million gallon leak.