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.
uses for Vermonts 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.
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.
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.
2000, the Agency and other groups and individuals interested in restoring
the states 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 Agencys 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.
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.