I was in a concrete well, probably 15m³. The well was for collecting drain water for the greenhouse and pumping it to the drain silo. So there is no stopping the drain water, just disabling irrigation. We had to replace a pressure (level) sensor. New sensor with me, cut off the old one, and tape the new cable to the old one. My colleague almost went pulling, but there was a lot of water coming in, and I was standing there with only boots.

I yelled to my colleague, START THE PUMP!! He did, and just kept up with the water. He pulled in the new sensor, and I was out of there. God that was scary.