I have a 2 acre pond in Georgia near a stream and I have historically had beaver problems for the past 20 years. They have had a lodge in multiple places on my pond. I have trapped and shot over 20 of them over a long period of time. It's a constant nuisance. They currently continue to dam up the drain. The drain is a 6 inch galvanized (I presume) pipe that goes straight down at the edge of the dam about 12 ft and turns 90 degrees to empty below the pond. The drain is in decent shape but the pond was built in the early 60s. I've used a go pro taped to a pole to evaluate the drain. I am concerned with the age of the drain and the constant attempts of the beaver to clog and dam this drain. I am considering putting in a 4" or 6" syphon drain that the beavers wouldn't be able to plug. I would assume I would fill the old drain with concrete or something else?? Any thoughts on making this modification? I've used a 2" temporary syphon to draw down the pond which made me think a permanent syphon would be better than the aging drain loved by the beavers! Thanks in advance and Merry Christmas.