Tensions over unanswered questions on how California’s largest water district might help pay for two proposed giant water tunnels boiled over into cursing at a meeting of the water district’s board members.

Gov. Jerry Brown’s administration is pushing to get financing and regulatory approval squared away for the $15.7 billion water tunnels. The 35-mile-long tunnels would divert water from Northern California’s Sacramento River before it reaches the San Francisco Bay, delivering the water to Central and Southern California cities and farms.

Current state proposals call for local water districts to pay for the tunnels, likely through customer rate hikes or other increased fees.

Metropolitan Water District, a wholesaler providing water to Los Angeles and 25 other cities, counties and water districts, stands to bear one of the larger shares of the cost if its board ultimately commits to the tunnels.

At meetings of Metropolitan’s board of member agencies on Monday and Tuesday, other board members twice blocked efforts by San Diego County’s representatives to schedule board discussions on how much cities and towns getting water from Metropolitan might be expected to pay for the tunnels.

“That’s bulls—-, Mr. Chairman,” San Diego County board member Keith Lewinger said Monday, after board member David DeJesus ruled that talk of scheduling a discussion on tunnel financing by DeJesus’s Metropolitan subcommittee would have to wait for some future meeting.

“I’ll quote you on that,” DeJesus replied.

Interviewed by phone Tuesday, Metropolitan general manager Jeffrey Kightlinger told The Associated Press he hoped to put the tunnels project before board members for consideration around March 2017, when the project should be further along in federal and state review.

Until then, talk of how the costs might be divvied up was premature, Kightlinger said.

So far, Metropolitan is the only large water district to say the tunnels could make financial sense for its customers, although its board has yet to vote. Metropolitan is one of at least four urban and rural water districts negotiating how to divvy up the project’s overall costs in talks convened by the state with the U.S. Bureau of Reclamation represented, according to state documents obtained by a tunnels opponent, Restore the Delta, through open-records laws.

San Diego County is one of Metropolitan’s largest water purchasers. Water officials there are turning to desalination, wastewater recycling and other means to try to more than halve water purchases from Metropolitan by 2020. They fear they would be asked to bear a large share of the tunnels’ costs regardless.

San Diego County water representatives complain Metropolitan has rebuffed their requests for any financial proposals on the tunnels.

“We haven’t been provided virtually any information from the project proponents,” Dennis Cushman, assistant general manager at the San Diego County water district, said by phone. “Fundamentally, who’s in? Who’s going to pay what? Questions we’ve been asking literally for five years that go unanswered.”