The Oakland City Council will vote this evening on whether to grant 8 more acres to the East Bay Zoological Society, which runs the Oakland Zoo, for the Society’s highly controversial development in what opponents call “the heart of Knowland Park.”

The project, which the Council has already approved, will develop about 56 acres of publicly-owned land, located between the MacArthur Freeway and Anthony Chabot Regional Park, that was given to the City of Oakland by the State of California in 1975 on the condition if it ceases to be a park, it would “revert to the State of California.”

The project could begin next year, and has a budget of $61.4 million. Proponents say the approved development will leave 319 acres of Knowland Park untouched, and that the site is ideal for the Zoo, its animals, and visitors.

“Without this plan there would not be a plan for habitat preservation, species protection or long-term management of Knowland Park,” said Dana Riggs, a wildlife biologist and consultant working with the Oakland Zoo, at a special Community and Economic Development Committee meeting at City Hall last week.

But opponents of the Zoo’s proposal, who have been ardent about their objections for years and continue to challenge it, also spoke up at that meeting.

“We want to talk about saving wildlife, about habitat preservation, and here we are being told that the best way to do that is to put 40 buildings on top of extremely rare habitat and a home of a threatened species,” said scientist and Oakland resident Beth Wurzburg. She said that in the approved exhibit, children will look through elevated glass walkways at the open grassland, but will not be able to set foot in it. “Don’t sacrifice it for an ill-planned exhibit planned on top of the best part of the park,” Wurzburg said.

Zoo officials are asking the City Council to grant 8 additional acres, in addition to the previously approved 45, for the “conservation easement” needed to secure permits from state and federal agencies. This is because the proposed development would be built atop habitat for the Alameda Whipsnake, which the U.S. Environmental Protection Agency has designated a threatened species.

If the Zoo is able to manage those 8 additional acres, officials argue, the snake could be assured of more shrub habitat. The 8 acres would not be fenced off, like the 30 acres of the approved development. Instead, “No Trespass” signs would be posted in this steep, densely vegetated area, which is rarely frequented by hikers.

Proponents of the project have said the whole expansion project will allow for greater public access to the park, while providing jobs and boosting the local economy. The Zoo’s financial director, Nik Dehejia, said the project was a win for Oakland, a win for the environment, and a win for children and families.

“The zoo has a vested right to proceed with the approved 2011 project,” he said at the meeting last week. “We respectfully request that council finish what it started.”

Opponents are still fighting the expansion as a whole, as well as approval of the conservation easement. The public, they say, would have never approved the loss of so much land if the full details of the easement had been included in proposal. Last month the Oakland Parks and Recreation Advisory Commission failed to recommend the easement to the city council, with five commissioners voting to approve the project, two voting against, and three absent. Six votes are required by the commission to approve a project.

Expansion opponent Sandra Marburg, who lives near the Oakland Zoo and has been following the development plans for more than 20 years, said the project has dramatically changed over that time. The Zoo originally planned to transport visitors to their expansion site via quiet electric motor cars, she said, and to build a 5,000-square-foot visitor center. Now the plans call for an aerial gondola, as well as a visitor center, gift shop, restaurant and administrative offices, totaling 34,305 square feet. Not a single environmental group in the East Bay approves of the project, she said, except those working with the Zoo. “It’s been challenging for us,” she said.

Three-quarters of the existing maritime chaparral—a woody shrub that provides a warm humid micro-climate and shelter for Gray fox, skunk, bush rabbit, California Quail as well as passageways for mountain lion—would have to be removed or trimmed due to construction and regulations, said Laura Baker of the California Native Plant Society, which opposes the project. The chaparral can also withstand fires, Baker said, and only grows in select places where the tectonic plates have provided the right soil conditions.

The maritime chaparral at Knowland Park is one of six stands in the East Bay. San Francisco State University researcher Michael C. Vasey has praised them for their ecological diversity and complexity. In Transect, a publication of the University of California, Vasey called the six stands of chaparral, the “Galapagos of the coast. Each little archipelago has its own set of endemic species. They are all islands of diversity within the broader system.”

Over the years, as the plans have been refined, Zoo officials have made such concessions as redesigning the fence around the 30 acres of development and 22 acres of proposed conservation easement, to allow for the passage of small creatures and hikers—though, opponents argue, large animals like mule deer and mountain lions, the only top predators that can co-exist with humans in the East Bay, would lose direct access to the Arroyo Viejo Creek.

Zoo officials say that they have also scaled down the size of their project, which had once called for an amphitheater and roads through the park. They have also promised to pull out non-native plants in some areas of Knowland Park, which is officially under the stewardship of the Zoo; and to follow the best practices to prevent during construction the spread of the tree disease called Sudden Oak Death Syndrome.

Opponents, on the other hand, say the Zoo should conduct a full Environmental Impact Report before building begins, even though Alameda Superior Court ruled in 2011 that such a report from the Zoo is not necessary. Baker, from the California Native Plant Society, which sued the Zoo, said that it could have further challenged the Zoo in court but lacked the tens of thousands of dollars they needed to hire a lawyer pro-bono.

At the end of last week’s meeting, District 4 council member and incoming Mayor Libby Schaaf, who promised to tour Knowland Park with opponents before the upcoming vote, said the city had already approved the project and might face legal challenges if the council did not approve the 8 acres for the easement now.

“Many of us work very hard to try and find compromise and try and incorporate all the disparate feeling of all the people we are elected to represent,” Schaaf said. She asked whether the Zoo could move the project closer to its current facilities. A representative from the city’s planning department said that was not feasible, due to visitor access, slopes and waterways.

“I am satisfied that this is appropriate to approve at this point,” Schaaf said.

Councilmember Lynette Gibson McElhaney, District 3, said she toured the Zoo with opponents and proponents the day before, and believes the development will not harm Knowland Park.

“We as a council have already approved this project,” Councilmember Patricia Kernighan, District 2, said. “The question is, are we are just going to do the formality of approving the conservation easement that has been recommended by state and federal wildlife agencies?”

Kernighan said that she was aware of the competing values. “I totally know the passion and love that many of you have for the space untouched as it is,” she said. But Kernighan said she thinks the rest of the park will be in better shape with Zoo’s habitat management plan included in the expansion.

“You can just walk for days and days and days and days and enjoy open space in my council district,” said District 7 Councilmember Larry Reid. He said a lot of time and resources have gone into negotiations over the years. “We just need to get past this issue,” he said.