The long-stalled overhaul of Balboa Park’s central mesa won’t kick off until at least this fall — if at all.

The Plaza de Panama project is again snarled in court. Supporters and organized opponents expect two appellate court cases to keep shovels out of the ground until at least October.

Save Our Heritage Organisation, or SOHO, and San Diegans for Open Government both challenged Superior Court decisions in suits they filed after the City Council approved a new financing plan for the project in 2016. The San Diegans for Open Government lawsuit attacks the city’s plan to borrow money to pay for its share of the project. SOHO argues it should have conducted more environmental reviews.

Yet philanthropist Irwin Jacobs and Mayor Kevin Faulconer, who revived the project nearly two years ago, aren’t giving up.

The city and the Plaza de Panama Committee, led by Jacobs, have finalized construction designs and plans for the project, which aims to clear cars from the center of the park. Jacobs said he’s also looking at ways to cut costs in light of the significant spike in the project’s sticker price since its initial approval in 2012.

Jacobs says he’s optimistic about the prospects for the estimated $80 million project. The Qualcomm co-founder plans to lead efforts to raise at least $30 million from private donors once court cases are resolved.

“I remain confident that we’ll be able to proceed,” Jacobs said.

But Jacobs is not certain.

The San Diegans for Open Government case filed by attorney Cory Briggs has hit hardest. The city can’t seek bonds – the source it counted on for up to $50 million – until Briggs’ lawsuit is off the table.

Briggs alleges the city should have gotten voter approval before the City Council signed off on a plan to borrow money to cover its share of the Plaza de Panama project, and raises questions about the city’s agreement with the Plaza de Panama Committee.

Last year, Briggs challenged a judge’s ruling in his trial court case, moving the fight to the state Court of Appeal. In an unusual circumstance, Briggs’ appeal will need to be addressed and then Superior Court Judge Gregory Pollack will revisit Briggs’ original case and arguments.

Briggs’ lawsuit, on the other hand, isn’t unusual. The city prevailed in a past Briggs suit challenging a similar bond financing plan for infrastructure repairs.

Both sides say the Court of Appeal case should end by this summer.

Attorney Scott Williams, who is representing the Plaza de Panama Committee, is hoping is hoping for a good outcome there and that the Superior Court judge will quickly wrap up that case once that appeal is handled. He believes the court will ultimately bless the Plaza de Panama project.

“In our review, Briggs has a weak case and has instead tried to achieve success through delay,” Williams said. “We are hopeful that the courts will recognize this strategy and will expedite the case accordingly.”

Briggs, on the other hand, said he expects to win and San Diegans for Open Government may consider further appeals if not.

Whatever happens, a top deputy to City Attorney Mara Elliott acknowledged the court cases have set back the project, perhaps mortally.

In a Dec. 27 court filing, Chief Deputy City Attorney Meghan Wharton wrote that Briggs’ suit had imperiled the project and, at the very least, would likely cost the city hundreds of thousands of dollars.

“As the Plaza de Panama bond issuance and the project continue to be delayed, the city and the (Plaza de Panama Committee) may face the decision of whether to abandon the project due to the delay or the increased costs of construction caused by the delay. Further, the delay of the Plaza de Panama bond issuance is increasing (the city’s) borrowing costs given the current trend of rising interest rates.Finally, the delay in issuing the Plaza de Panama bonds has created uncertainty as to the future of the project that could hamper the ability of respondents and the Committee to raise philanthropic funds to pay for the portion of the Project not funded by the Plaza de Panama bond proceeds.”

And the Briggs case is just one of the legal roadblocks facing the project.

SOHO, whose 2012 suit put the Plaza de Panama project on hold for years, is now battling an August Superior Court ruling in the city’s favor in appellate court too.

SOHO has argued the city should have conducted more environmental reviews after it resurrected the Plaza de Panama project in 2016. Pollack, the Superior Court judge, ruled that wasn’t necessary.

SOHO filed an appeal in October and both expect the case to play out for 12 to 18 months.

Williams and Christina Di Leva Chadwick, a spokeswoman for Mayor Kevin Faulconer, said the city could seek bonds and start construction once the Briggs case is resolved – even with the SOHO appeal pending – given the favorable Superior Court ruling in that case last year.

A spokeswoman for City Attorney Mara Elliott did not respond to Voice of San Diego’s questions about the Plaza de Panama court cases.

Bruce Coons of SOHO said his group would seek a formal court stay to halt the project if the city tries to move forward with it without finality in the SOHO case. He said SOHO’s also prepared to take its case to state Supreme Court.

“There’s not a path forward without resolving these court issues,” Coons said.

Williams, Jacobs and Chadwick expect all those efforts to fail.

“The Plaza de Panama project has consistently withstood legal challenges and we fully expect that to continue despite the efforts of a small group of opponents to derail this important project,” Chadwick wrote in a statement.

Disclosure: Irwin Jacobs is a major supporter of Voice of San Diego.