Neighbor messed around with that tannerite, might as well have just let out a big fart, all it did was make noise. Maybe he didn't do it right, dunno I wasn't there, I showed up after the nosie, sounds just like dynamite that I do know lol.
If you can rig up something like a lifting jib or gin pole onto a loader bucket, that allows you to more easily reach far enough from the banks to open the dams up if thats all you are trying to do. I've seen them rigged on backhoe hoe buckets similarly for reaching in and cleaning culverts as well.
Best is to get someone to trap them or shoot them. Even as a land owner I believe here in Alberta you need a permit or such for trapping, but nothing to shoot them. Back when I lived in Parkland county, they paid a 20 buck bounty per tail you dropped off at ag services as it saved them having to send out their own trapper and control personnel, now here with Athabasca, can't even get the bastards to look after the dams on road allowances anymore, never mind trap and eradicate the animals.
If you want to save them, shoot them from behind in the back of the head, otherwise the buggers will dive before they die and you can't always get hold of them lol. I had a shepherds style hook I used to use to fish them out. Also they are smart like magpies, I found setting up a blind I could sit comfortably behind was best and had a stick to replace the gun barrel for when I wasn't there. Trouble is, never really had the time to do it, good job for kids thou if they into that kind of stuff. Have my coyote trapper after some on my land right now, he's doing it more as a favor for me as I guess they aren't worth it anymore, cheaper than a coyote, can thank all the doo gooders in the world for that he says.
Contracts are made to be broken, a handshake is the law of God.