That is my experience, they rebuild it...the drainage worked well..i used 2 pieces 100' long, 4" diameter
surrounded with wire mesh so they cant just put mud over it...50' on each side of the dam...it keeps the water level from rising, they will just enlarge the dam every year...
Im all out of drone pics atm...lol... ill get on them in the Spring..The trapper would come by every year or two, but young ones would just move in ...