Tallest Beaver Dam?

Beaver dams are amazing constructions of wood, rocks, and mud that dwarf their makers. Apart from termite mounds they may be the tallest structures made by animals other than humans. Unfortunately there aren't many measured records of dam-building champs to rely on. I've heard reports of and found dams that were about 12 feet (about 3.7 meters) tall but I've never seen a study describing dam dimensions and the folks at the Guiness Book of World Records don't seem to be too interested in beaver dams.

The photo with this post shows a tall beaver dam from Algonquin Park in Ontario. Using Norma as a guide (she's 64" tall) and considering she's not standing at the lowest base of the dam I estimate this dam is pretty close to 10 feet tall.