The Williamsburg Reservoir Dam Failure of 1874

The Mill River valley in 1874 reflected the pattern of development during the early industrial era in Massachusetts, with numerous factories powered by Mill River water as it dropped 1100 feet in elevation to the Connecticut River. The villages of Williamsburg, Skinnerville, Haydenville, Leeds, and Florence, had grown around the sixty four mill factories of the valley. These factories produced buttons, silk, wool, cotton, brass fittings, iron tools, and tobacco products. The Mill River provided a primary ingredient needed by these factories – power from the volume and height of fall of the water. Control of the water for consistent and predictable power gave rise to numerous dams along the valley, the most important being the upstream Williamsburg Reservoir Dam, which captured the spring runoff for power during the drier summer months.
The industrialists who built the factories and the dams were a remarkable group – inventive, hard-working, adaptive, political, and compassionate, and they were, by necessity, cooperative in their shared use of the Mill River. However, their human characteristic of Yankee frugality and the physical features of the valley proved to be the major factors in America’s first major dam disaster. On Saturday morning, May 16, 1874, the persistent seepage pressure through the Williamsburg Reservoir Dam and foundation finally caused the steep downstream slope of the dam to slide away, releasing the 2000 acre-feet of stored water down the narrow valley, wiping out the valley villages and factories and killing 139 people.
The story of the Mill River flood tragedy paints a fascinating picture of industrial age society, starting with the physical setting and people, the construction of the dam, the remarkable individual actions during the flood, and ending with the post-flood responses. The story also provides a cautionary tale of the potential for poor dam design and construction by industrialists with resources, a story which would be repeated in 15 years, with loss of life consequences 16 times as great, in the Johnstown flood of 1889.