A developer who has been fighting for five years to build housing in a Berkeley parking lot that American Indians say is part of a sacred shellmound accused the city Thursday of trying to eviscerate a new state law that allows affordable housing projects to be fast-tracked.

In March, the developer, Blake Griggs Properties of Danville, became the first in the state to invoke SB35, authored by state Sen. Scott Wiener, D-San Francisco, that allows residential developers to bypass local environmental review processes in exchange for providing more affordable units. The developer expects the city to approve the project within 180 days — by Sept. 4, it said, as required by SB35.

The 260-unit project, planned for a parking lot across the street from Spenger’s Fresh Fish Grotto in West Berkeley, would dedicate half its units to low-income residents, defined as those earning 80 percent of the median income for the area, or $80,400 for a family of four.

But in a June 5 opinion, Berkeley city planners said the project did not meet the criteria for fast-tracking under the state law because it is within Berkeley’s shellmound historic site and would therefore require demolition of a historic structure.

It said the application conflicts with various city requirements and urban design codes in its general plan. Also, planners said, city code requires housing units to be affordable for life while SB35 requires the designation to last 55 years.

Blake Griggs informed the city Thursday that it still expects approvals by Sept. 4 or may consider legal options.

“The city’s approach now attempts to eviscerate SB35 — contending that the city will not approve the project even if the project satisfies all of SB35’s criteria, as well as creatively re-interpreting the law,” said the developer in a statement summarizing a 400-page submission to the city, including maps, addendums and other material, responding to Planning Commission concerns.

American Indian groups, as well as Berkeley antidevelopment forces, have long opposed building on the 2.2-acre parcel at 1900 Fourth St., contending it is the site of a sacred Ohlone burial ground.

The site is part of the West Berkeley Shellmound, a city landmark since 2000. Representatives of three autonomous Ohlone family bands — Confederated Villages of Lisjan, Himre-n-Ohlone and Medina Family — have been fighting the project.

“The parking lot is smack dab in the middle of the shellmound sacred historical site. It was documented that way by the city of Berkeley,” said Sherri Norris, the executive director of the California Indian Environmental Alliance, which is supporting the Ohlone people. “People who live around there are not supportive of building high-rises on that site and fast-tracking the desecration of a sacred site.”

Besides housing, the development would include a community center, a 7,000-square-foot park and 27,000 square feet of retail space.

The new state law streamlines the approval process for zoning-compliant projects that provide certain levels of affordable housing, unless they involve destruction of wetlands, historic sites or other important structures. In Berkeley — as well as in San Francisco and Oakland — a development must be at least 50 percent affordable to take advantage of the law.

Such projects are guaranteed approval within 180 days, a lightning-quick time frame in most of the Bay Area, especially Berkeley, where housing developments can take as long as four years to get permitted.

Jennifer Hernandez, the lawyer for Blake Griggs, said the 180 days will be up on Sept. 4, when the developer will be forced to consider filing a lawsuit.

“We have to assure that the law is enforced, so if the city doesn’t comply with the law we have to keep all those options open,” Hernandez said. “It would be a true shame for Berkeley to spend its taxpayer resources to defy state law.”

Berkeley Mayor Jesse Arreguin said he cannot comment because the issue is still under consideration and he will eventually have to vote on it.

Lauren Seaver, the vice president of Blake Griggs, dismissed all the city’s complaints. She said 40 borings down to bay mud, geotechnical testing and ground-penetrating radar showed no evidence of a shellmound on the site. She said an 1850s map showed two shellmounds in Berkeley, one to the east and the other to the west of the site.

Besides, she said, the site has already been designated by the city for multifamily housing.

“This is the ideal location for transit-oriented development,” Seaver said. “It is adjacent to the train platform for the Capital Corridor train and an AC Transit bus hub.”

Wiener this week backed off a previous statement that the West Berkeley development was exactly the sort of project he had in mind when he drafted SB35. He said Thursday he has recently met with both sides and cannot endorse either position.

“If it can’t be worked out through the process, the courts will make a decision,” he said.

Hernandez accused Berkeley of throwing up red tape, which she likened to putting the project in an endless washing machine spin cycle, saying the situation is exactly what the law was designed to prevent during a housing crisis.

“Unfortunately, we’re at a point where we’ve proven that this is not a shellmound site and the other side doesn’t want to develop anyway,” she said. “If Berkeley is allowed to flout SB35 and stop housing, then other cities will as well. I think this is your classic example of a very important first test of whether cities are really willing to approve low-income housing.”

Meanwhile, the Bay Area Council, a business-sponsored public policy advocacy organization, voted Wednesday to endorse the project.

Peter Fimrite is a San Francisco Chronicle staff writer. Email: pfimrite@sfchronicle.com Twitter: @pfimrite