Flush him down the drain!

Furious Queens residents dumped on Mayor Bill de Blasio on Sunday as they blasted the city’s crappy response to a clogged sewer main that flooded more than 80 basements with foul-smelling wastewater a day earlier.

“De Blasio should be here,” Nydia Cardoza Alvarez, 36, seethed while helping her parents clean out their home in South Ozone Park.

“It was disgusting. You could see the poop and toilet paper. There is still water in our basement up to your ankles.”

Neighbor Janice Harmon agreed that “de Blasio needs to see this mess” himself.

“The city is doing nothing for us,’’ she said. “The [Department of Environmental Protection] told me I had to leave my doors and windows open, but they couldn’t be responsible for any theft. I slept in my car to watch my house.”

“They said they couldn’t put my family in a hotel because I’m a homeowner. If I rented, they’d put me up.”

On Sunday afternoon, as rain fell and the temperature hovered in the 30s, de Blasio was a no-show at an emergency community meeting at Jamaica’s PS 223.

City Councilwoman Adrienne Adams (D-Queens) told the crowd the mayor “is aware of what happened and all these [city representatives] are up here because the mayor wants them here.”

A man in a Health Department windbreaker offered advice to the residents on how to deal with the foul stench in their homes.

“While you’re ventilating [your property], you can send your family to stay with friends or other family,” the man said. “We don’t believe [the smell] is harmful.”

The more than 100 residents in the room erupted in anger.

DEP Commissioner Vincent Sapienza eventually calmed the crowd by saying, “The city is taking responsibility for this,” and he instructed residents to “make sure you tell your insurance company that the flooding was due to the municipal infrastructure.”

Workers from the Comptroller’s Office distributed claims forms and helped people fill them out.

Sapienza said 82 of about 300 homes in the affected area were officially registered as flooded but noted that “there may be more, as it is a holiday weekend.”

The DEP said the blockage was believed to be located in a 48-inch main located south of the Belt Parkway and that workers were installing a by-pass pump to route sewage past it.

The composition of the clog was unclear, but the DEP noted that “grease, fat and oil” — common by-products of last week’s Thanksgiving feasts — were the “No. 1 cause of sewer backups.”