I have a new favorite beaver-plugging-culvert article and its from the Okabena-Ocheda Watershed District in Minnesota. This is the money quote:
Dammed: Beavers return to block culverts, halt water flow
WORTHINGTON — Beavers and high school students were both on the docket for Tuesday’s meeting of the Okabena-Ocheda Watershed District Board of Managers, as its members continued focusing on improving water quality in the area.
Water leaving Lake Ocheda flows south into the Ocheyedan River to get to Lake Bella, and all winter water was flowing past the beaver lodges there, keeping the animals happy, explained Watershed Administrator Dan Livdahl.
Then stoplogs were put into the dam late last month, halting the water flow until it builds to a higher level.
“No water is coming out of Lake Ocheda yet, so the beaver downstream are going a little crazy,” Livdahl said. “And when they have a good dam building situation, they can build very significant dams in those culverts overnight.”
He’s been going out to the site daily to check, because if the beavers are allowed to build for any length of time, they can plug the culverts badly enough that it’s hard to clean them out.
Those darn beavers! Insisting on having enough water so they don’t freeze to death in their lodge. Just who do they think they are anyway?
Several people do trap beaver in that area, but it’s been a running battle for the watershed district.
“It seems as soon as we trap them, another group moves in, so you have a very short break,”
Our solution NEVER ever works but dammit, we keep trying over and over. You would think we’d learn something new or maybe read something new on our phones. But we are from public works, We only have these hammers in our toolbox but so we keep using them.
Somethings gonna work eventually right?
By building dams and lodges, beavers are considered ecosystem engineers. Their dams raise water levels, slow water speed and change water direction, which can increase wetland size, enhance wildlife and plant diversity, improve water quality and maintain stable water temperatures. Beaver ponds provide habitat for freshwater fish, migratory birds, amphibians and other wetland species.
April 7 is International Beaver Day! This amazing semi-aquatic rodent is native to our state. Throughout California, the North American beaver (Castor canadensis) serves an important role as a keystone species and “ecosystem engineer.” 
