HG&E is the current owner of the Holyoke Dam, Canal System, and associated hydroelectric facilities, which it purchased from Northeast Utilities (Holyoke Water Power) in 2001. Electrical output from this hydro system provides approximately two thirds of Holyoke’s annual electricity use. HG&E received Low Impact Hydropower Institute (LIHI) certification for its hydro system in 2012 and was recertified in 2017. Refer to the sections below to learn more about HG&E’s hydro facilities.
Holyoke Dam and Hadley Falls Facility
The Holyoke Dam is a granite dam that spans the Connecticut River between Holyoke and South Hadley and diverts water from the river into the Holyoke Canal System and HG&E’s Hadley Falls Facility. The 30 foot high granite dam that you see today was constructed between 1895 and 1900.
The Hadley Falls Facility is located on the Holyoke side of the Holyoke Dam and contains two hydroelectric generating wheels with a total installed capacity of approximately 33 megawatts. The first wheel was constructed in 1951 and is known as Hadley 1. The second wheel, known as Hadley 2, was constructed in 1983.
Holyoke Canal System
The Holyoke Canal System is a three-tiered, 4 ½ mile system that runs throughout downtown Holyoke and provides water to approximately 11 in-service generating stations which have a total combined capacity of approximately 17 megawatts. The three Canal System tiers are known as the First, Second and Third Level Canals, and the drop between canal tiers, as well as the drop from the Canal System back into the Connecticut River, allows HG&E to generate up to three separate times using the same water.
The Canal System was constructed over a 46 year period, and was completed in 1893. Hydro facilities on the Canal System were developed between 1893 and 1985 and, historically, were generally initially utilized by factories to drive mechanical equipment and were later converted to electrical wheels.
In addition to operating a source of carbon free electrical generation and conducting various environmental studies, HG&E has made the following environmental enhancements since its acquisition of the Holyoke Hydro System in 2001:
- The installation of a full-depth louver fish exclusion system and bypass at the entrance of the Canal System in order to enhance the safe downstream passage of migrating fish.
- The installation of a weir in the First Level Canal for the protection of an endangered mussel species during periods when the canal system is drained for maintenance purposes.
- The modification of the Fishway in order to increase its capacity to pass upstream migrating fish over the Holyoke Dam.
- The conversion of Hadley Falls operations from Peaking to Run-of-River, which protects upstream habitat by minimizing water level fluctuations.
Rubber Dam Crest
HG&E, in cooperation with Northeast Utilities, oversaw the installation of a new rubber crest on the Holyoke Dam during the summer of 2001. This inflatable crest replaced a flashboard system originally constructed in 1900 and allows for more precise control of water levels upstream of the dam. The crest is a unique low pressure rubber bladder manufactured by Bridgestone, and installation involved: nearly 23 tons of reinforcing steel; 600 cubic yards of concrete; over a mile of air piping; and, approximately 1,500 steel tie down bolts.