WACHUSETT WATER: Dam-Reservoir-Aqueduct: Construction Photographs 1895-1906

Following the connection in 1849 of Boston’s first municipal water supply to every household in the city, and continuing into the early 1890s, Boston regularly increased its water supply capacity. But it barely kept pace with increasing demand due to annexations, population growth, and greater per capita consumption. The system also had to increase reservoir capacity for dry years. By the early 1890s its various sources’ maximum outputs had been nearly reached and the quality from some was deteriorating. Boston needed a much larger, more secure and further distant source. And it was just the largest of several metropolitan area municipalities needing additional water. This was a metropolitan problem, needing a metropolitan solution — and in 1895 a new Metropolitan Water Board came into existence.Drawing from a unique archive of photographs, together with introductory texts, maps, diagrams, and captions, this 208 page volume visually presents the construction of the Metropolitan Water Board’s’ Wachusett Reservoir, then the world’s largest for drinking water, together with its granite dam and aqueduct. Included are includes some 180 images selected from an archive of 7,672 large format, glass plate photographic images made to record the new Metropolitan Water Works and its operations. Photography began with commencement of the Wachusett project and approximately 6,100 negatives were made by its 1906 completion. That archive has been recognized an “absolutely unique” detailed day to day record of such a massive construction project at that time. Aside from engineering drawings, no comparable set of images records the construction Boston’s many other early reservoirs and aqueducts.The 63-billion gallon, 129 foot deep, Wachusett Reservoir submerged some six square miles of land, including two riverside towns. Everything had to be cleared, including grubbing out and burning all tree roots and removing up to a foot of organic top soil. And much of the reservoir’s 35 miles of shoreline, had to be armored by a broad band of hand laid, stone rip-rap.These photographs of this monumentally scaled, highly organized engineering project show an undertaking largely accomplished with manual labor — including Italian immigrants, living in sod hut camps, doing the tough soil clearance, and crews of black concrete workers brought up from “the southland.” There are also hundreds of horses, and ingenious, if often primitive seeming construction technology, including rail mounted steam shovels; narrow gage steam trains for hauling soil (whose tracks had to be constantly repositioned manually as the work progressed); and a pair of steam powered cable “aerial tramways” spanning between track mounted timber towers.Other images show an 1897 experiment “to determine the distribution of the stresses in masonry dams resulting from the external loads [by measuring] the movements of various points vertically and horizontally [in models] . . . under different conditions of loading, [and] inferring the stresses by direct proportion from these movements.” The project also included construction of earthen dikes that had to be built on both side of the reservoir where the natural land surface was below the reservoir’s maximum height and the sandy glacial soil was too permeable. These dikes are in effect separate earthen dams with impervious cores. The longer North Dike’s two sections, totaling more than two miles in length, required huge “cut-off” trenches up to 60 feet deep by 30 feet wide at their base with 1:1 sloped sides. For much of their length these trenches reached the water table before encountering impervious material, requiring six-inch thick timber core-wall extensions of sheet-piling driven up to an additional 60 feet below the trench bottoms. The trenches were then filled with denser soil dug from the bottom of the reservoir and made compact and water-tight, to provide sufficiently dense dike cores. Read more