Mills and Dams

The Merrimack River was extensively used not only for its resources, but also for its hydro power for the grit mills and saw mills that sprung up along its banks. The abundant waters of this river as well as the contours of the land make the Merrimack a very good source for hydro power. The great water power of the river was developed primarily due to the power looms that were introduced along its banks in the late 1700s (Meader, 1869). The power loom, though very rudimentary, was introduced in MA as early as 1787.

Prior to that, in 1708, the town of Billerica on the Concord River authorized construction of a dam (Meader, 1869). It was constructed for the saw and grain mills. In 1793, construction on the Middlesex Canal connecting the Merrimack river with Boston was commenced. In 1822, it was enlarged for manufacturing purposes. Construction on the Merrimack Canal commenced the same year. The system of canals that linked Boston with Concord was completed by 1817. These involved the construction of various dams across the Merrimack which made the passage of fish almost impossible.

In the mid 1800s the area around the river started getting transformed from a predominantly rural setting to one of mills and industries. Cotton mills were common place especially in the cities of Lowell and Lawrence. With the city of Boston becoming an important commercial center, the Merrimack River was considered for its transportation potential as a corridor between Boston and other manufacturing areas. The waters of thus Merrimack were redesigned to accommodate the large scale textile manufacturing needs. In 1822, a dam was built across the Merrimack above the Pawtucket Falls in order to divert enough water to the Pawtucket Canal. In 1830, a permanent dam was built across the river and in 1833, two more feet of granite were added bringing the total height of the Pawtucket Dam to 15 feet (Steinberg, 1991).

It was during the 1820s that textile mills began to move closer to the watershed regions mainly in search for more power to run the mills (Steinberg, 1991). The first dam that succeeded in completely blocking the passage of migratory fish was the dam at Lowell. It was completed in 1847. This dam limited the salmon run in the main stream to about one-fifth of what it had previously been. After this a series of dams followed suit ending with the Amoskeag Dam in 1871 which had a system of waterpower generation operating on two levels (Jerome et. al., 1965). A dam at Lawrence was built in 1848. It was the largest one on the Merrimack averaging 32 feet in height and spanning a distance of 1600 feet. This dam was the first among a series of dams that the Atlantic Salmon had now to jump over in order to reach its spawning grounds.

The Merrimack valley and other areas of New England soon became the largest manufacturing hub in the Western World (Meader, 1869). By the later half of the nineteenth century the valley was producing a large number of goods: timber, paper, textiles, leather, hats, wagons, mattresses, cigars, railway cars etc. The vast amounts of water that the Merrimack offered were ideal for this magnitude of economic development. The running waters were perfect avenues for washing off their waste products to the sea far beyond! The river was used to generate power, carry factory and human waste, and to supply water to the large population surrounding it. Organic pollution accounted for most of the waste that was produced in the textile industry; inorganic components like acids were also discharged. As the number of industries grew, so did the population in cities like Lowell, Manchester and Lawrence. In 1880, the population of Lowell increased, by over 45%, in just ten years to sixty thousand (Steinberg, 1991). Several new cities also sprung all across the valley. Population densities were also high. By the 1880s, the Merrimack River became one of the most controlled rivers in the world!

As the number of industries grew in the Merrimack River valley, it started becoming a dumping ground for all their wastes. This was a significant source of pollution by the 1860s. The Pacific Mills, which began operation in 1856, caused severe pollution downstream of the Lawrence dam due to their dyes and chemicals. A report published by two zoologists, Theodore Lyman and Alfred Reed in 1865, examined the obstruction to fish in the Merrimack and Connecticut rivers. They concluded that constructing fishways on the dams and preventing pollution in the rivers were important steps that would need to be taken in order to restore the rivers with salmon and shad.

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