Project Summary

The City of Westfield, Massachusetts with a population of about 40,000 lies in the foothills of the Berkshire Mountains. In 1898, a water supply consisting of a small reservoir and pipeline was built where water would flow by gravity to the City. In the 1930’s, a larger reservoir, the Granville Reservoir (photo at right), was built upstream to increase the supply. In the 1930s, a larger reservoir, the Granville Reservoir, was built upstream to increase the supply.  At that time, the original transmission pipeline was replaced except for about of mile that runs through a scenic gorge mostly inaccessible to modern construction equipment. 

With Hoyle Tanner’s assistance, the City replaced this older portion of the raw water transmission pipeline running through the gorge. A combination of trenchless technology methods and open-cut construction was utilized. The pipeline diameter was increased to restore the original flow capacity and provide excess hydraulic head to power a new hydroturbine located in the basement of the filter plant. It can produce about 37 kW roughly equaling the power consumption of the plant. The projected payback was 15 years and net economic benefit to the City over the next 40 years estimated at $7 million.