Wachusett Dam

Wachusett Dam
Wachusett Dam at Clinton
Official name	Wachusett Reservoir Dam
Location	Clinton, Massachusetts, USA
Coordinates	42°24′13″N 71°41′16″W
Construction began	1897
Opening date	1905
Operator(s)	MWRA
Dam and spillways
Impounds	Nashua River
Height	205 ft
Length	965 ft
Reservoir
Creates	Wachusett Reservoir
Wachusett Dam Historic District
U.S. National Register of Historic Places
U.S. Historic district
Location	Clinton, Massachusetts
Architect	Shepley, Rutan and Coolidge; Olmsted Brothers
MPS	Water Supply System of Metropolitan Boston MPS
NRHP reference No.	89002269
Added to NRHP	January 18, 1990

The Wachusett Dam in Clinton, Massachusetts impounds the Nashua River creating the Wachusett Reservoir. Construction started in 1897 and was completed in 1905. It is part of the Nashua River Watershed.

This dam is part of greater Boston's water system, maintained and controlled by the Massachusetts Water Resources Authority (MWRA). Its discharge is into the Nashua River. When it was completed in 1905, the Wachusett Reservoir was the largest public water supply reservoir in the world. At that time, the Wachusett Reservoir Dam was the largest gravity dam in the world as well.

Construction

The Metropolitan Water Board selected the south branch of the Nashua River in Clinton as the best site for Boston's new water supply over New Hampshire's Lake Winnipesaukee, Maine's Sebago Lake, and the Merrimack River.

Churches, factories, homes, and schools within the valley had to be knocked down or moved. Roads and rail lines had to be relocated; a railroad tunnel and trestle had to be built in order to relocate the Central Massachusetts Railroad, and over four thousand bodies had to be dug up and moved in the local Catholic cemetery. The project brought thousands of immigrants to the area for work.

The dam created the world's largest water supply reservoir at the time. It is still considered the largest "hand dug" dam in the world today.

Early problems

A static liquefaction flow failure occurred in the upstream slope of the North Dike of Wachusett Dam near Clinton, Massachusetts on April 11, 1907 during the first reservoir filling. The fine sands of the upstream dike shell liquefied and flowed approximately 100 meters horizontally into the reservoir. This caused many Clinton residents considerable concern. However, the project’s Chief Engineer, Frank E. Winsor, assured the townsfolk that everything was okay. This event remains controversial. At least one engineering study claims that the initial failure is a precursor to the dam’s future failure. However, it has now stood for over one hundred years.

Gallery

• 
  Wachusett Dam outlet
• 
  The reservoir side of the dam
• 
  The plaque on the dam
• 
  Rough-hewn rocks lining the reservoir
• 
  The reservoir itself
• 
  The dam from downstream

See also

• Wachusett Aqueduct
• National Register of Historic Places listings in Worcester County, Massachusetts

External links

• Wachusett Dam at Structurae
• USGS