Hultman Aqueduct Area

The Hultman Aqueduct Area was documented in 1985 by Louis Berger and Associates. The following information is taken from the Mass. Historical Commission Form (PDF).

About the Area

The Hultman Aqueduct is an 18-mile-long pressure conduit extending from near the Wachusett Aqueduct terminal chamber in Marlborough to a point in Weston near the Charles River. The aqueduct includes:

  • a 9,700-foot segment of cut-and-cover with 12-foot by 6-inch steel cylinder reinforced concrete pipe
  • a 3-mile rock tunnel beneath Sudbury Reservoir
  • 13 miles of 11-foot by 6-inch steel-cylinder reinforced concrete pipe 
  • a 170-foot twin-tube segment below Norumbega Reservoir in Weston

Structures associated with the Hultman are:

  • a semi-circular diversion dam on the Wachusett open channel
  • an intake structure
  • a head house at Shaft 4 (below Sudbury Dam)
  • a gatehouse and chlorine storage structure at Norumbega Reservoir. 

Contractors for the work included:

  • Weston Construction Co., Boston
  • B.A. Gardello, Boston
  • The American Concrete and Steel Pipe Co., Los Angeles
  • Carlo Biachi, Framingham

Consulting architects for the Shaft 4 head house and Norumbega Reservoir gatehouse was the Boston firm of Densmore, LeClear, and Robbins.

Historical Significance

The Hultman Aqueduct, built 1938-40, had its origins in the “Special Report of the Metropolitan District Water Supply Commission and the Department of Public Health Relative to Improvements in Distribution and to Adequate Protection of Pollution of Sources of Water Supply within the Metropolitan Water District,” published in 1937.

The Hultman was constructed to bypass Sudbury Reservoir, the watershed for which had become increasingly subject to pollution; and to bring clean water from Wachusett Reservoir directly to the Metropolitan Water District. The original plan for the “new pressure aqueduct” called for its extension all the way to Chestnut Hill Reservoir and for construction of a “tunnel loop” within the immediate Boston area.

The segment from Southborough to Weston was completed in 1940. With the nation’s entry in World War II, however, the “city tunnel” section to Chestnut Hill was delayed, Federal authorization having been denied on grounds that it was not essential to the war effort, despite intensive lobbying by the state legislature. Construction resumed in 1947, and the city tunnel extension was completed in 1950. Subsequently, the tunnel extension to Malden (1962) and Dorchester (1974) extended the pressure system into the heart of Metropolitan Boston. The Cosgrove Tunnel extended the system west to the Wachusett Reservoir upon its completion in 1965.


  1. Metropolitan District Water Supply Commission Annual Report 13 (1938) 15-16; and 14 (1939) 23, 25, 30, 31, 32.
  2. Dore, Stanley M., “Design and Construction of a Pressure Aqueduct for the Boston Metropolitan District.” Journal of the New England Water Works Association 55 No. (1941), pp. 315-354.