Had turtle block a drain from one of our wetlands. Got it out with a PVC pipe from the outlet side (it was dead). I added a closed cylinder of 2x4" wire fencing to the upper end and it seems to have worked to prevent more clogs. Did the same thing on a 12" culvert in a ditch crossing and captured a large carp coming upstream during a flood (headed towards my neighbor's pond). Unfortunately, his pond has already been invaded by carp.