SAN FRANCISCO — Golden Gate Park’s Hippie Hill is famous for the wafting aroma of marijuana just about any day of the week. But Sunday is 4/20, and to those in the know that’s code for “light up the ganja.”

It also happens to be Easter Sunday, and officials fear a repeat of last year’s massive daylong party that culminated in a crowd-sourced haze at 4:20 p.m. and then sent brain-fogged crowds flocking out of the park into the Haight district and as far as Hayes Valley.

There were only a few arrests but property was damaged and streets so clogged that buses came to a near standstill. Furthermore, Recreation and Parks Department staff and volunteers the following day gathered up more than 10,000 pounds of litter. (4/22 is Earth Day. So, not cool.)

Since the party does not have a permit or designated sponsor, there was no one to be held accountable.

But San Francisco Supervisor London Breed, whose district includes the eastern edge of the park and the affected neighborhoods, has crafted a plan to keep the event in order. Or at least more so.

On Wednesday, she held a news conference with San Francisco Police Chief Greg Suhr and two of his captains, Juvenile Probation Chief Allen Nance and Recreation and Parks General Manager Phil Ginsburg, to lay it out.

Uniformed and plainclothes officers along with juvenile probation officers will be in higher supply, Breed warned. Traffic officers will be towing anyone blocking a driveway or parking on someone’s lawn. Booths and concessions without permits will be cited and removed. And buses will be re-routed.

“San Francisco, as always, welcomes celebrants with open arms,” Breed said, “but this Sunday there will be boundaries to keep the com unity safe.”