They’re up s-ts creek, but they still have paddles.

Staten Island parkgoers have been fishing and boating in a lake polluted with human feces from a restaurant’s broken sewer line for over 20 years, and the eatery’s owner and park officials have done nothing about it, a whistleblower told The Post.

A sewer leading from The Stone House, a luxe wedding venue and steakhouse at Clove Lake Park, is badly damaged at multiple points and has been contaminating Clove Lake, a dye test performed by the city Department of Environmental Protection Tuesday revealed.

A spokesperson for the state Department of Environmental Conservation confirmed to The Post the agency is investigating “a potential sewage discharge into Clove Lakes Park.” The agency doesn’t comment on pending investigations, the spokesperson added.

The DEP said that the lake’s management falls under the jurisdiction of the city Parks Department and the pollution problem is now a state issue.

The test Tuesday involved pouring glowing green chemical dye down the restaurant’s toilets, and red dye in the sewer main across the lake that connects to the restaurant’s sewer line.

Both the red and green dye emerged inside the lake, indicating that the sewer was likely collapsed at multiple points, said the well-placed whistleblower.

The DEC nor the DEP provided test results for fecal coliform in the lake, and it is unclear if the lake has even been tested for bacteria related to human waste. The DEC water quality portal provides no data.

“I don’t know how the bosses can sleep at night, knowing that kids are fishing and families are rowing boats through sewage,” the source said.

The restaurant has allegedly long known about the busted sewer line, but did nothing to fix the putrid problem — and instead continued to rent paddle boats to unsuspecting parkgoers who went on to row in sewage, the well-placed source said.

The restaurant building is owned by the city but is operated by a vendor.

The Stone House’s 2022 licensing agreement with the city to operate the eatery and boat rentals included a stipulation that $200,000 be allocated for repairs, including on “drainage structures, plumbing and utilities,” according to documents reviewed by The Post.

The restaurant was on the hook to repair “two failing manholes” within the first year of the agreement, per the documents.

An amendment to the licensing agreement signed by the vendor and a Parks Department official in July said that both the vendor — who began operating the restaurant in 2014 — and the Parks Department were aware that “a sewer line collapsed.”

The well-placed source said that the busted sewer line was an “open secret” for years, and that the vendor pays “dramatically reduced” rent with the understanding he would cover the repair work.

The same source alleged that former Staten Island Parks Department Borough Chief Lynda Ricciardone and her deputy-cum-successor Joseph Homsey long knew about the toxic lake, but did nothing.

“The people at Parks should be embarrassed that the sewage spill is happening a stone’s throw away from their borough headquarters,” the same source said.

This is not the first crappy calamity to befall the 198-acre park.

Parks Department toilets were previously found to have polluted a creek at the park in a previous dye test, leaving the creek glowing a radioactive green, The New York Times reported in March.

The source claimed that in order to repair the lake, it would likely have to be completely drained unless some kind of dam could be built.

A plumber who worked at the restaurant 20 years ago, before the current operators took over, said that the restaurant’s pipes were always problematic.

“They had lots and lots of stoppages, every time you turned around they were calling, their dishwasher was always stopping up, our snakes would pull up mud, we didn’t know where it came from,” the plumber said.

The vendor, Homsey and the Parks Department did not respond to The Post’s requests for comment. Ricciardone could not be reached.