Water Distribution System
Needham's water system is a single service pressure zone system supplied by the Charles River Wellfield and supplemented by a connection to the Massachusetts Water Resources Authority (MWRA). The transmission piping consists of a large diameter piping network between the two water sources, water storage tanks and the major demand areas in the town. The Town of Needham has approximately 135 miles of water main ranging in size from four to 24 inches in diameter.
Needham's residential neighborhoods are supplied by a network of smaller diameter water mains. Within the water distribution system are approximately 2,000 gate valves used for isolation of areas during emergencies and system maintenance. Attached to the mains greater than six inches in diameter are approximately 1360 fire hydrants. The majority of the hydrants are owned and maintained by the Town while some are privately owned and maintained. Water is delivered to homes and businesses through privately owned service lines and metered for required billing purposes and consumption reporting to regulatory agencies.
System water pressure ranges between 25 and 115 pounds per square inch (psi). Water system pressure is maintained by pumping water from ether of the two sources up into the Birds Hill and Dunster Road storage tanks respectively, and then relying on gravity to maintain a constant pressure in the system. The higher in elevation that a particular home is built in relation to the water tanks, the lower the water pressure for that particular home or any home in that area. The inverse is also true for homes which are built in lower elevation areas of Town where they would have higher pressure. Massachusetts Department of Environmental Protection (MassDEP), Drinking Water Regulations requires that all public water suppliers maintain a minimum residual water pressure at street level of at least 20 psi under all design conditions of flow for all service connections onto the public water supply .
Water from the Charles River Wellfield and MWRA is transmitted through large diameter mains to two water storage tanks. The two storage facilities are located in the central and southeastern sections of Town. The tanks are designed to maintain pressure in the distribution system and provide water for firefighting needs.
The Dunster Road storage tank is a standpipe that is 55 feet in diameter and approximately 85 feet high with a total capacity of 1.5 million gallons. The standpipe is located at a high elevation area bounded by Hoover Road, Dunster Road and Dartmouth Avenue. The tank was built by the Chicago Bridge and Iron Company in 1950.
The Birds Hill Tank is also located at a high elevation area bounded by Hillcrest Road and Morningside Road. The tank was constructed in 1972 by the Fisher Tank Company and has a diameter of 100 feet and a height of 45 feet. The Birds Hill Tank has a capacity of 2.5 million gallons of water.