November 10, 2010 - dam removal on Martha's Vineyard

This summer I was fortunate to spend a week on the island of Martha's Vineyard in Massachusetts.  I learned about the island's energy resources, including solar and wind on Martha's Vineyard.

Photo: wind power near the islands: Falmouth, Massachusetts.

Following up on my recent looks at dam removal, today I'm looking at some possible dam removal activity on Martha's Vineyard.  It's what you might term a large-sized island: 87.48 square miles (231.75 km²), making it the third-largest island on the east coast of the US, and the largest island on the east coast not tied to land by a bridge or tunnel.  Population-wise, the year-round population of about 15,000 residents is augmented by tourists and seasonal residents, peaking at up to 75,000 people in summer.  Still, it's a manageable size, with all points of the island relatively accessible to visitors.

It's the relatively moderate size of Martha's Vineyard that made me surprised to learn that the island is home to at least 3,000 dams.  That's about 13 dams per square kilometer, or 34 dams per square mile.  The vast majority of these dams were built in the last 200 years to provide power, water, or both to mills -- almost all of which are no longer in operation.  With no maintenance, and no ongoing operations like hydropower production, many of these dams have become overgrown, forgotten, and in poor condition.

In response to a near-disaster in 2005 when rain-induced flooding nearly broke an old dam in a densely-populated area, the Commonwealth of Massachusetts enacted new dam safety and liability laws.  These changes made it more clear that whoever owns a dam is responsible for its safety -- and for the consequences of its failure.  Many property owners did not even realize that they owned aging dams when they purchased former industrial sites, like the Briggsville Dam in Clarksburg whose owner was surprised to find itself responsible for costly repairs or removal.

When costly repairs are required to maintain state and federal licenses and certifications, dam removal is one option.  Some dams on the Vineyard still provide valuable services, like flood control or providing water supply to residents and businesses.  Others, like the Mill Pond dam in West Tisbury, impound water for scenic and recreational purposes.  Still others remain in streams, holding back small ponds, in unknown condition.  Some may be candidates for removal, while others may be candidates for powering up as small hydro-electric sites.  As an island interested in sustainability, as well as reliability, it will be interesting to see which Martha's Vineyard dams are removed, and which will be restored.