We have a 3 acre ish farm pond that was built in the 70's. The pond has since filled in which is what it was designed to do, catching eroded soil. We need to dredge it out but haven't gotten around to it. Since it is only about 5 ft deep clear across, the pond vegetation has made it impossible to fish w/out getting hung up every 5 seconds but that's another story. We want to extend the drainage tube about 2 foot. The tube is constantly spilling out water and we thought this would be an easy way to add a couple feet of water to the pond.

How do you do this? So far we've come up with torching off a section of old culvert that use to run under a farm field entrance and then putting it around the existing tube and welding it together....Any other ideas?