From the Wellesley Trails Committee:
All it now takes to find out information about the aqueducts that traverse Wellesley is to walk on the aqueduct trails. Two interpretative signs about the Sudbury Aqueduct and one about the Cochituate Aqueduct shed light on the important roles that water-carrying conduits played in the development of Boston and surrounding communities.
In 2012, the State announced a policy to make trails more accessible to the public along several Massachusetts Water Resources Authority (MWRA) aqueducts that are no longer in active service. The MWRA initiated partnerships with municipalities for the enjoyment of these natural resources. Wellesley was already using the aqueducts for trail activities as a result of older verbal agreements but this policy change allowed the Town to enter into formal agreements that detail the specifics on exact location of the trails, permitted uses, maintenance responsibilities and other factors. These agreements preserved the MWRA’s primary water supply interest, while allowing host communities to become better stewards of MWRA land. As part of this program, the MWRA provided the interpretative signs to Wellesley.
Before 1795, Bostonians relied on local wells, rain barrels and a spring on the Boston Common for their water. In 1795, private water suppliers developed a delivery system, using wooden pipes made from tree trunks, to carry water from Jamaica Pond to Boston proper. By the 1840’s, the City of Boston had a population of 50,000 and faced water quality and capacity problems. Jamaica Pond lacked capacity and became increasingly polluted, which caused several epidemics. Several disastrous fires could not be contained due to lack of delivery capacity. A pure water source had to be found elsewhere.
The Cochituate System: 1948-1951
In 1845, the Cochituate Water Board began construction of a transmission system. A tributary of the Sudbury River was impounded, which created Lake Cochituate. With its 17 square miles of watershed, 2 billion gallons of storage and yield of 10 millions of gallons per day, it became the cornerstone of the Boston water system. The Cochituate Aqueduct was completed to transport water to the Brookline Reservoir from which pipelines were constructed to small distribution reservoirs in all parts of the city. The first water from Lake Cochituate flowed into the Frog Pond on Boston Common in 1848 at a dedication ceremony that drew 100,000 people.
In 1951, the Cochituate Reservoir and Aqueduct were abandoned. At that time, there were four aqueducts delivering water to the hub of the system and the Cochituate system was proved unnecessary. The water had also declined in quality and would have required treatment. With no need for the aqueduct, the State sold the land in Wellesley to the Town. The Cochituate Aqueduct interpretative sign can be visited by the Whole Foods parking lot where it was installed by Wellesley’s Department of Public Works.
The Sudbury Aqueduct and Chestnut Hill Reservoir: 1878
After the Irish Potato Famine of 1843-45, Boston grew rapidly and by 1870, its population exceeded 200,000. The water supply was not sufficient, requiring the Boston Water Works to construct the Sudbury Aqueduct between 1875 and 1878. It remained in use for almost 100 years, designed to carry water from the watershed of the Sudbury River to Boston and its surrounding communities. The mainstream of the Sudbury River was diverted via the Sudbury Aqueduct to the Chestnut Hill Reservoir. Both the Sudbury and Cochituate Aqueducts were designed to operate by gravity to fill the Chestnut Hill and Brookline Reservoirs. They were interconnected at Chestnut Hill.
The interpretative signs in Wellesley are located along the Aqueduct next to Dover Rd. and at the crossing on Brookside Rd.
The Sudbury Aqueduct consists primarily of a horseshoe-shaped brick lining that is 8.5 feet in diameter and 7.6 feet high. A number of construction methods were used along the route. These included two arched bridges — Echo Bridge at Hemlock Gorge in Newton and the Waban Arches in Wellesley — as well as cast iron pipes to cross a low-lying section in Wellesley, and a tunnel section in Newton and Natick.
The Sudbury Aqueduct carried 90 million gallons of drinking water per day 17.4 miles by gravity to feed the Chestnut Hill Reservoir, and from there to large pipelines and distribution reservoirs for use by Boston and the surrounding communities. The aqueduct was taken out of regular service in 1978 and now forms part of the MWRA’s emergency backup system. During the water main break of May 2010, the state resurrected the Sudbury Aqueduct to maintain the area’s water supply.
Sources: MWRA, Wikipedia, Wellesley Trails Committee