Opponents of Warriors’ Mission Bay arena appeal court ruling

Rendering released on Dec. 10, 2014 show the east aerial view of the Golden State Warriors' proposed new arena in San Francisco's Mission Bay area. The arena would seat 18,000 people, have a view deck, and include a 24,000 square foot public plaza on the southeast side and a 35,000 square foot public plaza on the Third Street side. Completion is slated for the start of the 2018-19 NBA season. less Rendering released on Dec. 10, 2014 show the east aerial view of the Golden State Warriors' proposed new arena in San Francisco's Mission Bay area. The arena would seat 18,000 people, have a view deck, and ... more Photo: Images Rendered By Steelblue., Courtesy Of MANICA Architecture. Photo: Images Rendered By Steelblue., Courtesy Of MANICA Architecture. Image 1 of / 9 Caption Close Opponents of Warriors’ Mission Bay arena appeal court ruling 1 / 9 Back to Gallery

The Mission Bay Alliance, the well-funded opponent of the proposed Golden State Warriors arena in Mission Bay, isn’t ready to give up its fight.

A week after a state Supreme Court judge shot down the group’s environmental challenge to the $1 billion basketball and entertainment venue, the alliance said Monday that it will take the case to the California Court of Appeal.

“Such an important environmental matter will be ultimately decided in the Court of Appeal,” said Osha Meserve, an environmental attorney for appellants. “The violations of environmental laws are blatant.”

The Mission Bay Alliance claims San Francisco city officials violated the California Environmental Quality Act, along with other state laws, when they signed off on the 2,300-page environmental report analyzing how the 18,000-seat area would impact everything from traffic to public transit to wind and shadows.

The opposition is largely funded by donors to UCSF, who argue that cars from the arena will create gridlock around the UCSF Medical Center at Mission Bay, which is across the street from the proposed arena. UCSF’s administration supports the arena.

P.J. Johnston, spokesman for the Warriors, said “whoever is funding the opposition must have money to burn, because they continue to lose badly.”

“The Warriors engaged in an extensive public planning process over several years. Our plan has been upheld by every regulatory agency and received unanimous approval at the Planning Commission and Board of Supervisors. Now our plan has been upheld by the Superior Court,” Johnston said.

Meserve said that the city’s environmental review “inexplicably” used “outdated analyses” to evaluate the project’s impact on “land use, biological resources, geology and hazardous materials impacts.”

“By relying on environmental review documents from 18 years ago, the city failed to analyze critical environmental issues that will impact city residents and visitors in the years to come if the arena is built,” Meserve said.

In addition to the Mission Bay Alliance, the appellant group includes the parent of a UCSF patient, Jennifer Wade, and SaveMuni, a public transit reform group. Gerald Cauthen, a transportation engineer and co-founder of SaveMuni, said “the deeply flawed arena EIR failed to assess and mitigate the project’s significant traffic, public transit and other adverse environmental impacts.”

But City Attorney Dennis Herrera said: “This event center is an important civic priority, which has been thoroughly scrutinized and has won overwhelming support every step of the way. I’m not surprised that the project foes are continuing to fight it, but I’m confident that our approval and review process will again easily pass muster in the Court of Appeal.”

The lawsuit was one of two legal challenges the Mission Bay Alliance has filed. The other, filed in Alameda County, seeks to invalidate an agreement between UCSF and the Warriors. That deal called for a $10 million Mission Bay Transportation Improvement Fund, which will be dedicated to directing the flow of traffic in the neighborhood, particularly during evening arena events.

J.K. Dineen is a San Francisco Chronicle staff writer. Email: jdineen@sfchronicle.com Twitter: @sfjkdineen