The Exeter photograph in the header at the top of this blog shows water flowing on both sides of the small Kimball Island linked to the mainland on each side by the String Bridge. The rocky river beds form the Great Falls where the freshwater Exeter River meets the tidal saltwater Squamscott. Beyond that we have the Great Dam. Not Great in a Niagara Falls sense but Great for early citizens who saw the potential for industry using the water power. There were once paper mills, powder mills, fulling mill (cloth), oil mills, a sawmill, a grist mill, a starch mill (from potatoes), pottery works, sailcloth factory, tanneries, a saddlery works, hat factory, a woolen mill and more that depended on the power of water.
This section of map by Phineas Merrill (below) in 1802 shows some mills. It also shows the Great Dam (Mill Dam), believed to be built in the first half of the 1600s. On the map are dams on either side of Kimball Island as well that were removed in the early part of the 20th century.
The Exeter Manufacturing Company (textile manufacturer) eventually bought out the mills in the early 1800’s, gained water rights, maintaining and eventually replacing the wooden dam with concrete in 1914. Water was fed through a penstock that snaked underground to the company for supplemental power production until the company was sold in the 1960s to the Miliken Manufacturing Company (synthetics for automobiles), who in turn sold the factory to no other than Nike for their first U.S. plant. Now those buildings are handsome brick condominiums.
With the stability of the dam in question and serving no purpose except as a reminder of the industrial history of the city, the townspeople voted in 2014, after a decade of planning and work, to remove the landmark dam. This will restore the Exeter River to its natural state, thus protecting the town from future flooding. The fish ladder installed in the 1950s was no longer needed as the free-flowing river will facilitate normal fish migration to their upstream habitat during spawning.
And so the earthmovers, excavators, surveyors, engineers, and a multitude of workers arrived this summer.
The dam is gone. The fish ladder is gone. The penstock (pictured unsealed in first photo) has been sealed but remain as a reminder of Exeter’s history. A temporary cofferdam allowed the water to flow on one side while rock clusters and boulders were strategically installed on the dry side.
Click on photo to enlarge…
That work finished, the riverbed side was reversed last week. Water is being lowered on the left, the cofferdam moved, and the river diverted to the right. Large rocks and boulders are delivered daily and precisely placed by excavator. The sealed penstock can be seen in the 3rd photo.
Finished with the the closest river bed, they’re continuing the work downstream. They will begin to stregthen the existing foundations and add riprap as was done upstream. Our extreme drought has slowed water flow to a mere trickle which makes work easier on this project but tragic for the whole seacoast area.
The removal and work below the Great Bridge on the dam and river has been one of Exeter’s well-attended spectator events. Along with other residents, we are among the regulars watching the action. Click photos:
Some struggle to watch and others never see a thing! But they still come…
In addition, the String Bridge is being repaired. There’s always a lot to bring folks downtown these days. Whether shopping, dining, running errands, many pause to see what’s going on around the Great Dam project. It’s a popular pastime in Exeter and will continue to be until mid-October.
The New Hampshire Dept. of Environmental Services printed on their website that there are more than 4,800 active and inactive dams in the state. Many were built in the 19th and 20th century for industry. To view a list of dams that have been removed and those that are planned, click HERE. I’m very happy that we’ll make the “Completed” list soon.