Sierra Wildlife Coalition, PO Box 7763, Tahoe City, CA 96145,  530-320-9923  sierrawildlifecoalition@gmail.com 

Beaver Dams & Lodges

Beaver Dam and Pond near Truckee

Beaver Dam near Lake Tahoe

Rock and cobble dam on a creek near Tahoe

Beavers build dams and ponds for safety only if water is not deep enough.  Water needs to be deep enought to escape predators, to provide underwater entrances to their lodges, and to provide access to food.  If streams are more than 3' deep they may not need to build a dam.

Often they will build one large pond with their lodge, and several smaller ponds up and/or downstream for access to food.  They use any available materials, including rocks, logs, sticks and other vegetation, then always pack mud against the structure for reinforcement.

Two types of Beaver Lodges:

- The 'classic' island/mound in the middle of a pond, or

 

- Bank lodges, which are dug into the bank of a stream,

  more common on smaller streams in the Tahoe area. 

 

  Both types always have underwater entries for safety from predators,

  and have dry chambers above the water for eating and sleeping.  

 

  Lodges are built up of logs, sticks and mud, or if they are excavated into       the bank, sticks and mud are added on top, for insulation and protection.

 

  Beavers never build lodges in their dams, as some think - that open/void     would weaken the dam, and Beavers are Nature's (best) Engineers! 

Island Lodge,

Grand Teton

National Park

at left

 

 

 

      

 

                Bank Lodge,

               Truckee River

               at right

Beaver Channels for safe access

Beavers are very good at digging, and often dig channels to have safe access to food and building materials - sometimes the channels start as paths, as in the photo at left.

Above, the beavers made a 2nd channel parallel to the creek to access their lodge, upstream on the left.