LIHI Certificate #170 - Dwight Project, Massachusetts

The dam, which was built ca. 1860, and consists of a 306-foot-long spillway and abutments. The northern abutment is constructed of cut stone and measures approximately 12 feet by 25 feet. The stone masonry overflow spillway is 15 feet high by 306 feet long, with a permanent crest elevation of 77.0 feet. The southern abutment is also constructed of cut stone, measures approximately 9 feet by 23 feet, and also serves as the north abutment of the headgate house. The dam creates and impoundment extending approximately 1,500 feet upstream with a surface area is approximately 32 acres.The canal headgate house is a brick structure on a concrete foundation, housing the six intake gates that control the flow from the impoundment to the power canal. The southern abutment of the canal headgate house is constructed of cut granite. The six head gates are all of timber construction, 5.5 feet-high by 8-feet wide. Each gate is equipped with a motor-driven rack and pinion operator.

The 80-foot-wide power canal extends 1,500 feet from the headgates to the penstock intake structure. The power canal extends another 1,500 feet further downstream where historically other industrial water users on the canal diverted the water from the downstream end of the canal. The south wall of the canal is of concrete and masonry construction while the north wall is formed from masonry and rock ledge. The canal is about 6 to 8-feet deep during normal operation.

The intake structure is constructed of concrete and measures approximately 69 feet by 22 feet. Steel trashracks span 54 feet of the north wall of the canal, across the three operable penstocks. A rail-mounted trash rake traverses the intake. Three float-activated, wooden, 8-feet-diameter gates are operated by rack-and-pinion operators. Three operable penstocks lead through a manufacturing complex to the existing units at the Project. The steel penstocks are 7 feet in diameter and 168 feet long.

The powerhouse was built in 1920 to contain three turbines-generator units that replaced the existing hydromechanical units at the site. The present generating capacity is 1.464 MW. The powerhouse was shut down in 1973, pending extensive repairs and was rehabilitated in 1980. The powerhouse was again shutdown in September 2013 and was not returned to full-time service until December 2016. The powerhouse contains three S. Morgan Smith turbines each with a nameplate capacity of 488 kW for a total capacity of 1.464 MW, averaging 3,493 MWh per year.

Project Name Dwight
LIHI Certificate No. 170
LIHI Certificate Term April 3, 2020 - April 2, 2025
Owner Central Rivers Power, MA, LLC
State Massachusetts
Location River mile 1.2, Chicopee River
Installed Capacity 1.464 MW
Average Annual Generation 3,493 MWh
Facility Type Run of river
FERC No. 10675, exempt 1992

Certification History

September 29, 2020: The decision to certify the Dwight Project became final after the close of the appeals period on September 20, 2020 with no appeals filed. The Certification term is from April 3, 2020 – April 2, 2025. There are three conditions on the Certificate.

  • Condition 1:The Owner shall consult with resource agencies on the need for interim and/or permanent upstream passage and, if warranted, downstream passage for American eel. The initial consultation request shall be made within 60 days of LIHI certification with completion of consultation activities within six months or as soon as possible after LIHI Certification, pending agency staff availability. If determined to be necessary, any agreed upon passage designs, implementation schedules, and plans for post-installation monitoring, maintenance and operations must be approved by USFWS and MDFW, as mandated in the Project’s Exemption, with SHPO consultation if needed. The Owner shall report on the status of these activities at six-month intervals from the date of certification until either: a) it is agreed that either upstream and/or downstream eel passage is not required during the LIHI Certificate term; or b) there is an agreed upon design and schedule in place. The Owner shall continue to report on the status of implementation activities in annual compliance submittals to LIHI until facilities are constructed and approved by agencies, or until such facilities are determined not to be needed.
  • Condition 2:The Owner shall consult with the SHPO before undertaking any ground disturbance, construction, repair, or modification to any site features listed in the documents describing the site features considered eligible for or listed on the National Registry of Historic Places. Should any such activities be conducted during the term of this LIHI Certification, such as the currently planned Project upgrades, a copy of the required notification/consultation with the SHPO and, if required, with FERC, shall be submitted to LIHI when such agency filings are made. The status of any work conducted following such review shall be filed as part of the annual compliance reports to LIHI.
  • Condition 3:The Owner shall consult with the City of Chicopee to see if there are opportunities to support the City’s currently planned expansion of the nature trail / Riverwalk along the Project area. Within six months of LIHI Certification, the Owner shall provide LIHI with evidence of consultation and any related agreements with the City. Any agreements should include a description of any proposed measures which the Owner will implement, and a timeline for completion. The status of activities implemented under such agreements shall be included in annual compliance reports to LIHI until completed.

August 21, 2020: The Low Impact Hydropower Institute (LIHI) has preliminarily approved the Dwight Project (pending LIHI #170) for a 5-year term of Low Impact Certification.

This decision is preliminary pending the 30-day appeal window. Only those who commented on the initial application during the 60-day comment period are eligible to file an appeal. Such appeal needs to include an explanation as to how the Project does not meet the LIHI criteria. Appeal requests can be submitted by email to with "Dwight Project” in the subject line, or by mail addressed to the Low Impact Hydropower Institute, 329 Massachusetts Ave, Suite 6, Lexington, MA 02420. All requests will be posted to the website. The applicant will have an opportunity to respond and any response will also be posted. Requests must be received by 5 pm Eastern time on September 20, 2020. The full application and reviewer's report are available below.

If no appeal requests are received and the decision becomes final, the Certification term for the Project will be April 3,2020 through April 2, 2025.

April 13, 2020: The Low Impact Hydropower Institute has received a complete application for Low Impact Certification of the Dwight Hydroelectric Project.  LIHI is seeking public comment on this application.  Specifically, we are interested in knowing whether you think the Project meets the LIHI Low Impact Certification Criteria, as revised in the 2nd Edition Handbook.  The Project’s application materials can be found below.

Comments that are directly tied to specific LIHI criteria (flows, water quality, fish passage, etc.) will be most helpful, but all comments will be considered.  Comments may be submitted to the Institute by e-mail at with “Dwight Project Comments” in the subject line, or by mail addressed to the Low Impact Hydropower Institute, 329 Massachusetts Avenue, Suite 6, Lexington, MA 02420.  Comments must be received on or before 5 pm Eastern time on June 12, 2020 to be considered.  All comments will be posted to the web site and the applicant will have an opportunity to respond.  Any response will also be posted.