Groundhog and muskrat burrows weaken the embankment and can serve as pathways for seepage. Beavers may plug the spillway and raise the pool level.
Rodent control is essential in preserving a well-maintained dam.
The groundhog is the largest member of the squirrel family. Its coarse fur is grizzled grayish brown with a reddish cast. Typical foods include grasses, clover, alfalfa sprouts, peas, lettuce, and apples. The average life expectancy is two or three years with a maximum of six years. Occupied groundhog burrows are easily recognized in the spring due to the groundhog's habit of keeping them cleaned out.