Vermont has more than 1,200 dams within its borders. While many have been breached and no longer impound any water, and others form ponds in low-lying areas, most are either on rivers or regulate the water level of natural lakes.

Principal uses for Vermont’s dams include power generation, flood control, water supply, and recreation. Many dams provide opportunities for quiet-water canoeing, boating, and fishing. They can also be used to raise the water level in lakes for the benefit of lakeshore property owners and other recreational users.

A river that has been dammed is no longer continuous, at least from an ecological standpoint. Dams prevent the movement of fish upstream, and frequently downstream as well. Sediment carried by a river is deposited in the still water impounded behind a dam, gradually filling in the impoundment. The energy of the moving water must be in balance with the amount of sediment it carries, and this often results in erosion below large reservoirs as the river picks up additional material to compensate for that deposited in the reservoir. Water impounded by a dam is more likely to warm up in the summer months, often beyond the threshold for the survival of cold-water fish species such as trout. Water that settles into the deeper portions of an impoundment may have so little dissolved oxygen that it cannot support fish and other aquatic species.

Dams also impose societal costs. They change the recreational value of a river and can also increase the likelihood or severity of floods by constricting the flow of the river or causing ice jams.

Finally, the financial and legal liability associated with dams is a significant issue. Dams are expensive to build and maintain. The Agency of Natural Resources owns and maintains more than 100 dams. These dams cost Vermont taxpayers $450,000 to $500,000 per year for operation and capital improvements. Dams abandoned by their owners eventually fall into disrepair, resulting in hazardous conditions downstream in the event of dam failure.

In 2000, the Agency and other groups and individuals interested in restoring the state’s rivers formed the Vermont Dam Task Force. Task force members are working with dam owners and local watershed groups to identify dams that are good candidates for removal or modification. The Agency’s recent assessment of dams in the White River Basin indicates that many impoundments are no longer serving a useful purpose and are falling into disrepair. Dam owners recognize their financial and legal liability, and often welcome assistance in removing such dams. In other cases, dams can be modified to mitigate their environmental impacts, such as through the construction of fish ladders.

There are numerous opportunities around the state to restore rivers by removing or modifying dams. The Agency of Natural Resources will continue to identify those opportunities and work with dam owners, watershed groups, and other partners to see these projects through completion.