excavator built a ramp below the dam to chisel the dam and apron apart. The 14-mile restored stretch of the Souh- egan River had Atlantic salmon parr nestled in the newly exposed rock and cobble by the following summer.
The head-of-tide dam on the Bellamy River in Dover, one of the projects funded by CCANH, is a great example
of innovation among project partners.
Currently, CCANH is funding anoth- Kevin Lucey, NHDES, Restoration Coordinator
are scheduled in 2010, and about 20 are under consideration. CCANew Hamp- shire has contributed to three of the 12 dam removal projects so far. Many times, federal funds are the primary source of revenue for dam removals, but non-federal match monies are needed to leverage the projects to completion.
RESTORING RIVERS In New Hampshire, the river restor-
ation process generally begins with a feasibility study to determine condi- tions both before and after a dam removal and to determine the final cost. There are “show-stoppers” to dam removal projects, including pro- hibitive sediment load or pollutants, the impoundment’s role as a public water supply, or the potential im- pact on other structures upstream. Sometimes dams are only partially removed because of historic or cost considerations. No two removals are the same, and site access can be an issue. The head-of- tide dam on the Bellamy River in Dover, one of the projects funded by CCANH, is a great example of innova- tion among project
partners. This
breached timber crib dam was built behind a mill between steep river banks. To minimize the destruction of
14
prime spawning habitat by heavy equipment running up and down the river to the dam site, the excavator and roll-off containers for the debris were lowered by crane directly on the dam site in November 2004. The excavator made short work of the dam remnants, piled the debris riverside, armored the river banks, and then loaded the debris into the roll-off containers suspended from the crane.
The work was finished within three days, and the crane then raised the roll- offs and excavator out of the restored riverbed. While only about a quarter of a mile of river was restored to diadro- mous species, the importance of open- ing the river’s tidal interface was real- ized by rainbow smelt the following spring. Monitoring showed spawning activity in the freshwater reach of the Bellamy River. Another dam removal made possi- ble with matching funds by CCA NH was on the Souhegan River, a tributary of the mainstem Merrimack River. The Souhegan River had an inordinate amount of sediment that had been col- lecting within the impoundment over the years. Prime Atlantic salmon rear- ing habitat had been compromised, and the downstream reaches of the Merrimack had been starved of sedi- ment and nutrients. In August 2008, an
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er project in the Winnicut River water- shed of Great Bay. The Winnicut Dam in Greenland, N.H., is another head-of- tide dam. Its removal in 2009 opened the entire mainstem of the river to diadromous and resident fish move- ment. While a fish ladder was built adjacent to the dam in 1957, it was of a design that would not effectively pass river herring. The N.H. Fish and Game Department spent many years at- tempting to retrofit the fish ladder, with only marginal success. When funds became available, Fish and Game decided to remove the dam and restore the river system. The project ultimately installed a 135-foot, in-river fish passage system, and the undammed Winnicut River is now the first significant free-flowing river in the Great Bay watershed. The diadromous species are celebrating. Obsolete dams plaguing streams, impacting the health and quality of rivers, and creating financial hardships for owners and communities are con- tinuing to be removed across the coun- try. Apart from the fish-eye view, dam removals can reduce an owner’s liabil- ity, eliminate or reduce localized flood- ing, improve water quality, attract new business, and improve recreational opportunities. Dam removals generally need many project partners to be com- pleted. It is often the owners, state and federal agencies, towns and communi- ties, and nongovernmental organiza- tions such as CCANH that make dam removals happen and river restoration a reality.
TIDE
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