A city plan to temporarily destroy a beloved Manhattan park in a bid to prevent future flooding is so hated, hundreds of activists “buried” the proposal in a mock funeral Saturday.

“Bury the plan, not the park!” was the battle cry from the more than 300 protesters who turned out to save East River Park — which the city intends to cover in up to 10 feet of fill to create a barrier against rising waters.

The highlight of the noontime march, which kicked off in Tompkins Square Park, was the “internment” of the city’s proposal, which activists covered in compost in front of a cardboard gravestone as a bagpiper sounded a mournful tune.

A “Reverend Billy” gave the last rites, then declared, “Let’s go dance!”

“We tried to convey to city officials our opposition, our disappointment,” trumpeted protester Howard Brandstein, executive director of the Sixth Street Community Center. “We thought maybe with the death of the plan, we can connect with them emotionally.”

A year ago, the city did an about face on a flood protection plan for lower Manhattan, infuriating residents with the hated proposal to cover up East River Park.

The proposal by the city’s Department of Design and Construction would, if approved, take 3.5 years to complete and begin in the spring of 2020.

Construction would close the park — which runs from East 12th Street to Montgomery Street — during the work, remove nearly 1,000 trees and trash recently upgraded park features, including a refurbished track and new soccer field.

The park, which opened in 1939, also has baseball fields, basketball and tennis courts and a historic amphitheater.

“This flood control project is going to completely destroy a 57-acre living park that people use all the time,” said Pat Arnow, a founder of the East River Park Action group.

The plan faces two key votes — the first on Monday as it goes before City Planning Commission. The City Council is expected to vote on the $1.4 billion project this fall.

Marchers stopped outside the East 4th Street office of City Councilwoman Carlina Rivera, whose district includes the park, where protesters sang, “Carlina, you’re breaking our hearts, don’t bury the park (baby),” to the strains of the Simon & Garfunkel classic, “Cecilia.”

The city contends this plan will be finished sooner than an earlier flood mitigation proposal, and that it will rebuild the park’s recreation fields and buildings and plant 2,800 new trees in the park and surrounding neighborhood.

“The 110,000 people living directly in the flood path cannot afford to wait,” said Jainey Bavishi, director of the Mayor’s Office of Resiliency.