Save the Sound and the Town of Wilton are gearing up to remove Dana Dam, also known as Strong Pond Dam, this spring to restore fish passage in the Norwalk River. The dam, originally installed by Charles Dana to create an ice-skating and swimming pond for his children in 1940, is the first barrier upstream of Long Island Sound and blocks passage for migrating fish such as alewife, blueback herring, lamprey, and eel in their search for suitable habitat to reproduce. Removing Dana Dam will restore 10 miles of habitat along the main stem and tributaries to the Norwalk River for migratory and resident fish, in addition to restoring the riverine ecosystem habitat for native plants and animals.
“The main purpose of removing a dam is environmental restoration,” says Alex Krofta, ecological restoration project manager at Save the Sound. “Dams trap sediment that would normally flow downstream to create riverbed habitat. Dams block the passage of fish and other aquatic organisms. Dams impair water quality by creating large, stagnant impoundments holding water with low oxygen levels and high temperatures, which are harmful to fish and other aquatic life. Most dams do not prevent or reduce flooding as people may think. Rather, they increase flood risk due to possible dam failure and reduction of natural floodplains that store and slow water flow. In addition to the habitat restored for migratory fish species—whose return will support populations of dozens of species of fish, birds, and other wildlife—this project will improve water quality and create new vegetated buffers, further supporting clean water and wildlife habitat.”
The first phase of construction, tree clearing, will begin the week of Monday, March 20, to allow access for work crews to demolish the dam and recreate a section of the stream channel.
To protect those who use Merwin Meadows Park, some trail sections may be temporarily closed during construction activities. Those sections include (1) the Norwalk River Valley Trail (NRVT) from the School Road spur trail to the wooden footbridge and (2) the access trail from the Wilton Railroad Station parking lot to the Merwin Meadows Park overflow parking area. These trails will be closed during active construction work hours only and will remain open during evenings and weekends. Safety precautions, such as road flaggers, will be used to ensure the safety of the public when equipment is actively moving around the site. We ask that park-goers obey safety personnel and signage at all times.
“Trees need to be removed for construction access,” says Krofta. “Work crews, excavators, and material need to be moved onto the site and concrete from the demolished dam will need to be moved offsite. We started with an estimate of 183 trees to be removed and have revised that down to about 80 trees, and we expect this number to be further refined. Save the Sound, Wilton, and the contractor are committed to cutting as few trees as possible.”
Trees provide habitat for many species of local wildlife at Merwin Meadows Park, which may include the endangered northern long-eared bat. To avoid disrupting habit where they might roost, nest, and raise their young, marked trees will be cleared before the beginning of their roosting season in April.
To bring tree diversity and abundance back to the site, staff and volunteers from partner organization Trout Unlimited have already committed to replanting two native saplings for every tree cut. The project’s long-term effect will support an ecosystem with improved habitat for bats and other native wildlife species.
The project’s multiple phases of dam removal and river channel restoration have been thoughtfully designed and planned to avoid as much negative environmental impact as possible, and the completed project will result in multiple unique habitats for all kinds of life.
“The site will go from an artificial concrete waterfall and unnatural impoundment back to a flowing stream,” says Krofta. “The new stream channel will consist of pools and shallow rocky riffles, as well as banks and floodplains with native vegetation. Part of the existing channel will be rerouted away from a railroad embankment to mitigate potentially polluted runoff and to stabilize the railroad. Construction will progress in phases. The dam itself will be taken down last and very carefully, using a jackhammer mounted on an excavator. This sequence is established for the safety of work crews, infrastructure, and the environment.”
After tree clearing, site work is expected to pick back up in May and the majority of the construction and demolition will happen in the summer when water levels are lowest in the Norwalk River. The removal is expected to be completed this fall.
“Connecticut has more than 5,000 structures disrupting the flow of our rivers and streams and segmenting habitat for fish and wildlife—the most per river mile in the country,” says Anthony Allen, Save the Sound’s restoration strategy director. “Most no longer serve a purpose and their lack of maintenance results in an increased risk of flooding due to dam breach or failure.”
Save the Sound is one of several nonprofits working hard to remove those dams as part of the regional Long Island Sound River Restoration Network. Fellow members include the Housatonic Valley Association, Farmington River Watershed Association, Trout Unlimited, Connecticut River Conservancy, American Rivers, and The Nature Conservancy in Connecticut. The Connecticut Department of Energy and Environmental Protection (CT DEEP) often leads on the removal of state-owned dams and is a critical partner on the removal of Dana Dam.
The removal of Dana Dam to restore the Norwalk River at Merwin Meadows Park has been in the making for over 15 years, and many local partners and funders have come together to provide essential support (in many forms) for this work. Primary project funding has been provided by the U.S. Environmental Protection Agency Long Island Sound Study (LISS), administered by the CT DEEP. , Additional project funding has been provided by Congressionally Directed Spending sponsored by Representative Jim Himes (CT-4), the Jeniam Foundation, the Anne S. Richardson Fund, the U.S. Fish & Wildlife Service’s Atlantic Coastal Fish Habitat Partnership and National Fish Passage Program, the New Canaan Community Foundation, and the generosity of many individual donors.
We encourage those interested in this project and for any dam owner interested in removal to reach out to Save the Sound at firstname.lastname@example.org for more information about freeing our region’s rivers.