I don’t see much said about them here. Do any of you offer them as part of your services?
Do they work in drainages, or will debris foul them?
I've installed several with a very high success rate. The problem with them is most people don't want to pay for them. Also most don't believe it will work.
I began experimenting with them just in back woods beaver ponds built out of only PVC pipe.
I've also built some using 12" HDPE culvert pipe that was installed through existing road culverts.
and yes they can foul with debris. This usually happens if you build them wrong. but could happen with a flood event or extreme erosion.
There are about 10 steps to building my version correctly. If you leave out one step it will fail or the beavers will figure it out and bury it making it a waste of time.
I sold/installed one to a local county road dept about 10 years ago ( I asked for the worst beaver spot they had )
This road flooded every time it rained. The county had dug the inlet to the two plugged 24 inch metal culverts out daily for several winters.
My leveler has kept this pond drained with zero maintenance ever since. ( also, zero beavers trapped , this area joins a very large swamp of several hundred acres )
Now for the Kicker- after watching mine perform so well for a few months they decided to save money and build their own. You guessed it... the one they built failed, after that they just went back to the old way, digging them out when they get stopped up.
One more thing, as you probably know every drainage is different, so every leveler may need some modification to make it work. There is no magic bullet