As soon as Beverly Hills developer Palisades Capital Partners announced plans in July to demolish a chunk of the former Metropolitan Water District building just outside of downtown, historic architecture buffs sent up the alarm.

A petition being circulated by Yuval Bar-Zemer of Linear City Development has garnered 300 signatures advocating for the city to designate the 53-year-old building a historic cultural monument.

“The majority of the people that responded are in a state of disbelief that a developer would even consider throwing the wrecking ball on the building,” Bar-Zemer said via email.

He bought a ’70s-era portion of the long-neglected site in 2011 for $6.8 million and transformed the office – designed by acclaimed modernist architect William Pereira – into luxury apartments called the Elysian.

Bar-Zemer had been in the running to buy the rest of the site but was outbid last year by Palisades, which paid $30 million for the 5.25-acre site then occupied by a church.

The Cultural Heritage Commission will vote on the matter Sept. 15. If it approves the application, the Los Angeles City Council has the final say. But monument status will not necessarily save it – only require extra reviews and approvals.

Palisades appears poised to press ahead with its original plan to construct a mixed-use project, no matter the outcome.

“Leading experts have determined that our property lacks any historical integrity,” the company said in a statement.