Great Works Dam, MHER Documentation

I’ve had the good fortune to carry out two projects for the Penobscot River Restoration Trust in Maine. The Trust is a non-profit organization that was created in order to carry out the Penobscot River Restoration Project in collaboration with a range of public and private partners. The goal of the Project is to restore the health of the river by removing several dams, and thus re-opening large stretches of the river to spawning fish, while maintaining the production of hydroelectric power. The two principal dams that were removed were built in the late 19th and early 20th centuries to produce hydroelectric power, and each replaced an earlier set of wing dams that were used for lumber mills. In both cases, the earlier dams remained intact within the impoundment of the modern dams. In part as a result of my research, both sets of wing dams were determined eligible for the National Register as historic engineering resources. Since the removal of the modern dams would have adverse effects on the older dams, the Maine Historic Preservation Commission recommended that each set of wing dams be documented for the Maine Historic Engineering Record (MHER), according to the standards of the Historic American Buildings Survey/Historic American Engineering Record. The Trust contracted with me to carry out both of these MHER documentation projects. Here is a record of one, the former wing dams that lay within in the Great Works Dam impoundment near Old Town.

Looking downstream

Picture 1 of 8

A view from the east bank of the river above the spillway, with the pulp mill in the background

The Penobscot is one of the mighty rivers in New England, second in scale only to the Connecticut River. It drains an enormous watershed of nearly 8,600 square miles, much of it in the northernmost reaches of the Appalachian chain in the vast wilderness of Aroostook County. The Penobscot Indians and their forebears relied on the fish in its waters, while European and American settlers added power to the bounties which the river provided. Enormous stands of timber of all sorts lie within the watershed, which hardy loggers felled and floated down the river. The stretch of river between Old Town and Bangor, meanwhile, has a fall in elevation that provided power to dozens of lumber mills. The dams that held back the water for the mills, however, also blocked the traditional runs of fish moving upstream for spawning.

The wing dams at Great Works were built originally by two separate companies, one on each side of the Penobscot River, in the 1830s. Each dam angled in toward the center of the river as it extended upstream. The two dams then met at a spillway in the center of the riverl historic dam at Great Works dates back to the 1830s. As a historic artifact, it is associated with several important contexts, including the gargantuan lumber industry on the Penobscot River throughout the 19th century, and the conversion of the forest products industry in Maine from timber to pulp for paper. Here’s how I summarized it in the MHER narrative:

The former Great Works Dam, located within the impoundment of the current Great Works Dam, was constructed as two structures in the early 19th century to provide water for two early sawmill complexes on the Penobscot River at Great Works: on the west, for the mills of Rufus Dwinel, and on the east, for the mills of the Great Works Milling and Manufacturing Company. These original dams, on each side of the river, were both built as wing dams that extended upriver and out from the river bank, and likely were built independently of each other. The two dams were then consolidated under a single ownership in the early 1880s by the Penobscot Chemical Fibre Company, who built an early mill for producing wood pulp for paper on the Penobscot River. These dams remained in use from the 1830s until the current dam was constructed in 1887, though the dam on the west side of the Penobscot may have been partially rebuilt in 1866, when a fire of the mills located on top of the western dam led to the sale of the complex. The remains of the dam are significant for their association with the early development of the timber milling industry on the Penobscot River, the transition from lumber production to wood pulp production, and as an example of early dam construction technology.

Originally constructed in the 1830s and possibly rehabilitated in the 1860s, the original Great Works dams were partially demolished in approximately 1887 when the current Great Works Dam was constructed. The remains of the original dam, which have lain within the impoundment since the modern Great Works Dam was constructed, have been revealed with the removal of the modern dam in the summer of 2012.

Because significant remnants of the original dam remain upstream of the current dam, fisheries experts have concluded it could become an impediment to fish passage once the Great Works Dam is removed, unless it is altered. Engineers and fisheries experts agree that only the upstream-most lateral section (perpendicular to flow) will need to be modified to allow for safe, timely, and effective fish passage. This means that the majority of the original Great Works dam structure – the sections parallel to river flow – will remain in their current state.


Here’s a plan of the dams in 1875, with the Penobscot Chemical Fibre Company on the left (west) bank and the Great Works Milling and Manufacturing Company on the right (east) bank:

1875 Great Works Map small

Unfortunately, relatively little of the original timber crib structure of the two wing dams remained above the waters of the Penobscot. Enough was visible, however, to glean important details about its construction and planning. Because of the rapid flow of the river, and the likelihood of debris just beneath the surface, I was not able to go out in a boat to get close-up photographs. I had to settle for views from the east and the west banks instead. The Penobscot River at Great Works is fairly wide, which meant that my photographs of both facets of the dam were taken from as much as 200 feet away. My aged Schneider 210 mm lens, although not as long a lens as I would like in that situation, was nevertheless up to the task and gave me some wonderfully detailed images. In addition, the entire modern Great Works Dam had been removed by the time that I did the photography, which meant that I was able to get relatively close views from the downstream ends of the dams looking upstream. These proved to be very valuable.

As a preservationist, I am always saddened to see good historic buildings and structures be removed. These artifacts are important reminders of our shared past and the efforts that our ancestors made, and provide the connections through time that are so vital to our identities. However, by incorporating the HABS/HAER documentation process into the removal process, we are able to learn about the methods that our forebears used that would otherwise be inaccessible.

While I could wish that I had closer access to the wing dams, I remain pleased with these images, and with the report that I produced. I had a great deal of help from the Trust, who were ideal clients, and from Leith Smith, the MHPC’s historical archaeologist who provided fantastic insights into the construction of the dam. It really was an honor and a pleasure to document this remarkable dam.

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