Thousands of gallons of raw sewage spilled into a popular College Point swimming hole last month — and locals are flushed with rage that they weren’t given enough warning about the hazardous event.

Roughly 7,100 gallons — enough to fill a backyard pool — poured into Flushing Bay on April 23 after a pipe routed to the nearby Tallman Island Wastewater Resource Recovery Facility burst, The Post has learned.

Rather than alert the media with a press conference or put up warning signs along the water, the Department of Environmental Protection did little more than send out a single notification via NYAlert, an obscure city text service that you have to sign up for in advance.

Residents say the news would have slipped through the cracks entirely if it weren’t for a lone neighbor who follows the relatively unknown information feed.

“We’re using these waters for recreation. We’re doing beach cleanups to dragon boating, kayaking, fishing and we should have a way of knowing what’s happening with our waterways other than some obscure messaging system that I guess you have to sign up for — if you are lucky enough to even know that the system exists,” fumed Kat Cervino, president of the Coastal Preservation Network.

“How many other times has this happened? I have no idea.”

The tainted water flowed into Flushing Bay, home to several yacht clubs and a tiny beach favored by swimmers and fishermen, after the sewage escaped from the busted 122nd Street Pump Station and into a stormwater catch basin.

The sewage gushed for five hours — at times reaching a velocity of 100 gallons per minute — before the DEP fixed the pipe, ultimately releasing a 7,084-gallon cocktail of human waste, food scraps and more into the bay.

“As for our communications with the authorities and community, an immediate notification was made to the New York State Department of Environmental Conservation, as required by law. A notification was also sent out via NY-Alert, as well as posted online,” a DEP spokesperson told The Post.

“Additionally, the DEP Queens Borough Commissioner spoke with staff from Council Member Vickie Paladino’s office since the pump station is located in her district.”

Paladino, however, says her office never heard from the DEP, but directly from Cervino instead. When the politician asked her DEP contacts for more information, they had no idea what she was talking about, she claims.

In a statement shared with The Post a day after publication, Paladino said: “This highlights serious breakdown in communication within DEP. My office should have received a personal notice about this, and the community should have been informed by DEP and by my office. My office has been in contact with the Borough President due to this breakdown, and we will work together to ensure the system of communication changes and this never happens again.”

Earlier this week, the DEC slapped the city with a violation for violating the City’s State Pollutant Discharge Elimination System (SPDES) permit by allowing the spill.

Residents of the quiet neighborhood said they were left completely in the dark — even after the DEC slapped the city with a violation relating to the incident on May 5.

“The fact that there’s no clear notification to the community is a huge, huge problem for us,” said Cervino, who was given the run-around when she tried to gain answers from the DEP.

“There needs to be a way that people are actually in the loop on this stuff so we can make smart decisions for our health.”

The Guardians of Flushing Bay, an advocacy group for the waterway, and the nearby Williamsburgh Yacht Club were also left in the dark.

The result: Swimmers, kayakers and fishermen continued to wade without any clue that the water had been tainted — including dozens who fearlessly dove in at Big Rock Beach when temperatures soared to 80 degrees just days after the reported spill.

“Yeah, ew!” said Stephanie Centeno, who lives next to the secret beach on 28th Avenue and witnessed crowds wading and picnicking.

“It’s normal, but they don’t know that it’s dirty. It’s green. It smells.”

The impacts of the incident are far beyond disgusting — and could be lethal, according to experts.

“These sewage-based pathogens cause infectious diseases in marine life. It also causes gastrointestinal infections and humans who are kayaking and who are coming in close contact with water,” explained Cervino’s husband, James Cervino, a visiting professor at the Woods Hole Oceanographic Institute and the environmental chairman of Queens Community Board 7.

“When these sewage outflows happen, all these fishermen that are catching fish legally and eating it — they’re going to get sick. Boaters come into contact with the water, they wipe their eyes, they wipe their mouth — they’re going to get sick. Whether it’s marine life or humans, this stuff is pathogenic.”

The bacteria caused by the sewage could also lead to a harmful algae bloom, which would release its own cocktail of toxins, which would further kill marine life and sicken humans, he continued.