A federal judge ruled this week against environmental groups who had sought an injunction to stop pumping and mowing activities at the Sharp Park Golf Course in Pacifica.

The golf course is part of the 417-acre Sharp Park, which is owned by the city of San Francisco and has served as an 18-hole public golf course since it opened in 1932.

Environmental groups including the Wild Equity Institute, the Sierra Club and the National Parks Conservation Association had argued that maintenance activities at the golf course harm the San Francisco garter snake, which is listed as an endangered species, and the California red-legged frog, a threatened species.

The groups said pumping at Horse Stable Pond in the park causes frog egg masses and tadpoles to be stranded and dried, and that grass mowing and the use of motorized golf carts kills the garter snakes.

But U.S. District Judge Susan Illston denied an injunction sought by the groups in a ruling issued Tuesday, pointing out that experts on both sides of the case agree that the frog population in the area has actually increased in the past 20 years, and that there has only been one confirmed case of a snake killed on the course six years ago.

Illston said in the ruling that “the circumstances do not warrant the exceptional act of prohibiting activity that has gone on for decades before the case can be decided on its merits.”

She noted that the city has pledged to continue carefully monitoring water levels and collaborating with U.S. Fish and Wildlife Services officials to move any vulnerable egg masses.

The city has also established a compliance plan in 2009 that includes “no mow zone” areas on the course and calls for the suspension of play if either a frog or snake is spotted on a green scheduled for maintenance, Illston said.

She added that no garter snakes have even been spotted on the green in the past three years, raising the question on if the species even exists in the area.

Supporters of the golf course lauded the judge’s decision.

“The court came to the right conclusion,” Richard Harris, co-founder of the San Francisco Public Golf Alliance, said in a statement. “The evidence clearly showed that the species are doing quite well at Sharp Park.”

The environmental groups said they were not deterred by Illston’s decision and are still pursuing the case, which is scheduled to go to trial in July 2012.

“We are excited to go to trial and expect the judge to craft appropriate relief once she has heard the merits of the case,” said Brent Plater, executive director of the Wild Equity Institute and legal counsel in the case.

“Though we are saddened there will be another season where harm will fall on these fragile creatures, we are confident in our ability to make a strong case for protection of both species in trial,” Michelle Myers of the Sierra Club said in a statement.

The case is scheduled to return to court on Jan. 27 for a status conference.

Meanwhile, the golf course also faces potential closure in a proposal by one San Francisco Supervisor to negotiate to hand over jurisdiction of the park from the city to the National Park Service, which would transition it to a new open space area.

The proposal, introduced by Supervisor John Avalos in September, is set to be heard in the board’s City Operations and Neighborhood Services committee at City Hall on Monday morning.

Dan McMenamin, Bay City News

Want more news, sent to your inbox every day? Then how about subscribing to our email newsletter? Here’s why we think you should. Come on, give it a try.

Please make sure your comment adheres to our comment policy. If it doesn't, it may be deleted. Repeat violations may cause us to revoke your commenting privileges. No one wants that!