18 Sep Building Beaver Dam Analogs
So much dam work
My main project this month was to work with the Montana Conservation Corps (MCC) to build Beaver Dam Analogs (BDAs) to reinforce already existing dams that have been built on a stretch of creek.
Why are beaver dams important? Well, they store water, decrease the speed of runoff going through the system and create a great habitat for wildlife-especially our native species.
How do we preserve the dams? Building BDAs is one of the most effective ways to reinforce the dams. The concept that we applied to this project area included taking wooden posts and driving them into the downstream side of the dam using a hydraulic post pounder. The idea is that the beaver will be enticed to add onto the damns with the added support and if not, the posts will collect debris that will naturally build up the dam. Either way the damns should be secure enough to take on the next large runoff event.
With the large amount of runoff that this region had, the dams were unable to withstand the large flows and resulted in numerous blowouts. However, the busy beaver got to work and rebuilt/maintained over 60 dams in just the 2 mile stretch of creek that we were looking at. It is quite incredible to see how resourceful the beaver are. Some dams were built of mostly large rock, some sagebrush, some reinforced with mud, and some were a few feet tall.
Results: 7 days with the MCC, a crew of 6, completed 50 BDAs using 750 posts along 2 miles of stream.