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.  Please review the program and criteria in LIHI’s revised Handbookand then review the Project’s application materials 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 comments@lowimpacthydro.org 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.

Project Description:

The Dwight Project (FERC No. 10675, exempt) is located in the City of Chicopee in Hampden County, Massachusetts, at approximate river mile 1.2 on the Chicopee River.

The project works include a stone masonry dam with a crest elevation of 77.0 feet (NGVD), an impoundment, a canal headgate house, a power canal, an intake structure for three operable penstocks, a powerhouse with three operable turbine/generating units, a tailrace channel (44.5 feet NGVD) and appurtenant facilities.

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.

Files

• 01A_Dwight Certification Application – REVISED
• Attachments 02-21
• Attachments 22-31
• Attachments 32-38
• Attachments 39-43
• Attachments 43A-63
• Attachments 64-84
• MDFW Dwight LIHI comments
• CRC comments Dwight LIHI 06-12-20