Montana Department of Environmental Quality (DEQ)

Beaver Ponds

Description:

Beaver ponds can be found through out Montana. These habitats are rich mosaics of diversity that are beneficial hydrologically, biologically and socially. Beaver (Castor canadensis) create beaver ponds through their woodcutting and dam building activities. Beaver dams create lentic (lake) habitat in an otherwise lotic (stream) system. These ponds retain sediment and organic matter in the channel, create and maintain wetlands, modify nutrient cycling and vegetation decomposition, modify the structure and dynamics of the riparian zone, alter hydrologic regimes and influence the character of water and materials transported down stream. ¹

Function and Values:

Beaver ponds provide a variety of functions and values. The creation and senescence of beaver ponds is extremely important in the creation of new wetland and riparian areas. These new environments are vital to the continued persistence of a variety of plant and animal species. Beaver ponds are also very important in maintaining the water quality and quantity with in our streams. They have the ability to trap and store large amounts of sediment, increase the retention time of water, thus reducing pollutant loads and hold and release water thus allowing intermittent and ephemeral stream to flow longer and at a more constant rate.

Photos of Beaver Ponds:

Photo by: Anna Breninger
"A wet Meadow/beaver ponds complex on Wheat
Ranch, South of Dillon, Beaverhead County"

Photo by Tom Hinz
"Beaver pond complex on Hughes Creek, a tributary
of the West Fork of the Bitterroot River"

Photo by Erin Farris
"Beaver pond along Jeff Davis Creek, in Southwest Montana"

Photo by Erin Farris
"Multiple beaver ponds along Carver Creek in Southwest Montana"

Photo by Lynda Saul
"A series of beaver ponds along the North Fork of
the Flathead River."

Distribution Map of Beaver Ponds:

Potential Stressors:

Trapping: In the state of Montana beavers are legally trapped during furbearer season. Except where designated there is no limit on the number of beavers that can be trapped and killed during the furbearer season. From 1996 - 2003 92,552 beavers were trapped and killed in the State of Montana.² This does not mean, since this is a state sanctioned action, that trapping and removal of beavers has no negative impacts on the ecosystem functions provided by beaver ponds. Through removing beavers, in general, all functions and values associated with beaver ponds are lost over time.

Dam Removal:

Photo by: Unknown
"Removing a beaver dam from stream."

Reference:

¹ Mckinstry, M. C. and S. H. Anderson. 2002. Survival, fates and success of transplanted Beaver, Castor canadensis, in Wyoming. Canadian Field-Naturalist. 116(1): 60-68.

²Montana Fish, Wildlife & Parks Furbearer Trapping Reports 2003-1996.