The ongoing deluge of sewage from Mexico has polluted the waters off Coronado, rendering them unsafe for swimmers. TC2412 - stock.adobe.com

They’re up s–t creek without a plunger.

Just when you thought it was safe to get back in the water: A picturesque California beach is at risk of being shuttered amid a deluge of sewage from Mexico that’s befouled the coastline.

“It was heaven on Earth, and now I call it paradise lost,” Whitney David, 63, a retired surgeon and surfer, told the WSJ of the odiferous scourge.

Posted signs at Coronado Beach warn the public of the pollution.…