Pond Boss Forums POND CONSTRUCTION Renovating a Pond or Lake? How to drain a large pond to do a repair? Ideas?

If doing a siphon drain, thinwall might collapse, and the belled ends might not seal 110% allowing air into the system and breaking the siphon unless they were silicone sealed together.

I have a 3" Honda trash pump. I disconnected the gas tank that came with it and use an outboard motor gas tank sitting on a 5 gallon bucket next to the pump. Gravity feed from the outboard tank, not a suction feed. A 6 gallon tank will run the pump for close to 18 hours running wide open, and almost 30 hours at half throttle. I use semi rigid suction hose, 4" flex "roll flat" hose to get to the top of the pond basin, then 4" (Not 3") belled thinwall sewer pipe to get the water away from the pond. Some discharge runs are in excess of 150 feet, and by using 4" discharge on a 3" pump, and having the pump as close to the water level as possible to push water not suck it, I surpass the rated GPH discharge of the pump.