The river was named for early fish weirs. In 1928 the building of a aqueduct connecting the Ware River to the Wachusett Reservoir commenced a major public works undertaking. The massive horseshoe-shaped conduit, known as the Wachusett-Coldbrook Tunnel, had to be blasted through solid rock at a depth of. The arrival in 1931 of the first water from the Ware River by way of this tunnel probably saved the Wachusett Reservoir from drying up, for a prolonged drought had reduced Wachusett’s water supply to less than 20 percent of capacity. In 1933 the Quabbin Aqueduct was completed, ready to transport water from the Quabbin Reservoir under construction. The Swift River Diversion tunnel is in full use, bypassing water around the dam area.
Topography
The Ware River starts at an elevation of about above sea level, fed from the numerous small streams within its watershed, before ending at the village of Three Rivers at an elevation of about. The river flows through many historic mill towns where its fall towards the sea provided power. One of the largest such towns is Ware, Massachusetts, which shares its name. This river is part of the Connecticut River Watershed.
The Barre Falls Dam is located on the Ware River in Hubbardston, Massachusetts, about below the junction of the river's east and west branches and northwest of Worcester. Designed and constructed by the United States Army Corps of Engineers, this dam substantially reduces flooding along the Ware, Chicopee, and Connecticut rivers. Construction of the project began in May 1956 with completion in July 1958 at a cost of $2 million. The project consists of an earth fill dam with stone slope protection long and high. There are three dikes totaling in length, with a maximum elevation of. Cut in rock, the spillway comprises a concrete weir in length. The weir's crest elevation is lower than the top of the dam. There is no lake at the Barre Falls Dam. The flood storage area for the project, which is normally empty, stores floodwaters and covers about in the towns of Barre, Hubbardston, Rutland, and Oakham. The entire project, including all associated lands, covers. The Barre Falls Dam can store up to of water for flood control purposes. This is equivalent to of water covering its drainage area of. The Barre Falls reservoir is located within the Upper Ware River Watershed. The MassachusettsDepartment of Conservation and Recreation manages and preserves the land for water quality protection. The Massachusetts Water Resources Authority manages these water resources, which are part of the public water supply for the metropolitan Boston area.
The Ware River Diversion facility feeds Ware River water into the Quabbin Aqueduct. This is used to start a natural siphon so water can flow from the Quabbin to the Wachusett Reservoir, or from Wachusett Reservoir to the Quabbin Reservoir.