DUBLIN — An Alameda County Superior Court judge recently solidified a win for environmentalists who sued the city of Dublin over a ballot measure that paved the way for potential development of protected open space.

Seth Adams, a director of Save Mount Diablo, said Judge Michael Markman’s Nov. 19 decision was a “huge victory” and “one of great holiday cheer.”

“You’ve got to stand up to bullies,” said Adams, whose organization was one of two groups who sued the city, including another group called Friends of Livermore. “Dublin has been a bully in this situation.”

When over 53% of Dublin voters approved Measure II in November 2024, it allowed the city to decide on potential commercial development in the Doolan and Collier canyons, an area beyond an urban limit line established in 2014 to protect 3,282 acres of open space near the Dublin-Livermore border.

Dublin City Manager Colleen Tribby and Mayor Sherry Hu did not return requests for comment on the judge’s ruling.

Shari Jackman, a city spokeswoman, wrote in a statement Tuesday that the city “has the ability to appeal the decision. However, any decision on whether to appeal would need to be considered by the Dublin City Council.”

Judge Markman wrote that by putting the measure on the ballot, “there is an ‘eminently reasonable possibility’ that the city will use its new authority … for the eventual development of at least some portion” of the area. This warrants further environmental study of the area, Markman wrote, and the city was obligated to do that before City Council voted to put the measure on the ballot.

The ruling brings the city “back to the drawing board,” Adams said.

In court documents filed after an Oct. 1 tentative ruling against the city, the city’s attorneys argued that an environmental review “would require the City to speculate as to what types of land use decisions could be made by City decision makers in the future and their associated environmental impacts — even though no such decisions have been made, applied for, or even proposed.”

They also argue that the California Environmental Quality Act, or CEQA, “does not allow a court to force agencies to change their activities solely to allow for a meaningful review of the activities’ environmental impacts.”

Measure II, after approval, “indisputably did not change the existing physical conditions of the environment and … did not change the ‘planned future conditions’ discussed in any plan,” the city argued.

Judge Markman also acknowledged that this case “presents an unusual situation.”

But in his final decision, Markman jabbed back at the city, writing that if the city “determines that any specific impact is too speculative, the correct course of action is to document that determination in an EIR (environmental impact review) or other CEQA document — not to skip CEQA review altogether.”

Considering the year and a half of litigation this case took, Adams noted that the decision came “very quick, as far as courts are concerned,” and added that “an appeal would take considerably longer.”

But, he added, “we were confident from the beginning” that the courts would decide in their favor.

“A lot of time city officials and lawmakers assume they’ll get away with deceiving the public because it’s expensive and difficult to challenge them,” Adams said. “Rather than saying you can’t stand up to City Hall, what residents learned is that you really can stand up to big, well-funded development interests, and make them follow the law.”