LIHI Certificate #3 - Putnam Project, Connecticut

Project Name Putnam
LIHI Certificate No. 3
LIHI Certificate Term April 10, 2017 – April 10, 2027
Owner Putnam Hydropower Inc.
State Connecticut
Location Located at river mile 38. 4 on the Quinepaug River in the northeastern corner of Connecticut.
Installed Capacity 0.6 MW
Average Annual Generation 2,750 MWh
Facility Type Run-of-river
FERC No. P-5645 exempt 1982

The Putnam Project is located in the northeastern corner of Connecticut, in the town of Putnam, on the Quinebaug River. The dam dates to the pre-Civil War era circa 1830, and the powerhouse was constructed in 1919. Operation of the hydroelectric project commenced in October of 1987 after a lengthy outage and refurbishment. The project lies between the upstream MSC hydroelectric project and the downstream Cargill Falls project. Other nearby projects include the Mechanicsville Project (LIHI #74) upstream on the French River and the Quinebaug development (part of LIHI #166) downstream on the Quinebaug River The project includes a dam, powerhouse, spillway, and two Francis turbines.

The dam is 14.5 feet high and 145 feet long, made of stone block. The powerhouse is located on the western dam abutment with an open flume that conveys water to two identical vertical axis Francis Turbines. No bypassed reach exists in the project area as the powerhouse is adjacent to the dam. The project operates in a run-of-river mode and impounds a 2-acre reservoir. The project provides a minimum flow 144 cfs into the downstream reach of the river. This flow regime was developed based on consultation with US Fish and Wildlife Service. Run-of-river operations are maintained utilizing a programmable logic controller system which also ensures a stable impoundment level. The upstream Army Corps of Engineers’ flood control operations at West Thompson Dam on the French River regulate flows to this section of the Quinebaug River.

Waters within the project reach are impaired for non-attainment of primary recreation designated uses. This non-attainment of water quality standards is likely due to upstream industrial/municipal discharges, urban runoff, and flow regulation via the other hydropower facilities, flood control dams, and consumptive water withdrawals. Issues of nutrient loading and water withdrawal are not caused by the project as concluded by the Connecticut Department of Energy and Environmental Protection (CTDEEP).

Historically, Atlantic salmon were present in the project watershed. However, the construction of downstream dams extirpated the species. Additionally, no anadromous fish species were able to migrate up the river to the project reach due to the downstream Cargill Falls, a natural falls that preclude access to the project area. However, the catadromous American eel is present in the project area. The project owner has installed a Delaware style eel passage to promote upstream eel passage. This type of eelway consists of a hole through a structure near the crest of the dam. By passing trawl netting or similar rope-like material though the hole, a roughened route for eels to ascend over the dam is created. The project owner has also implemented a voluntary operational regime that includes shutting down generation during rainy nights between September 1 and November 15 to promote effective eel downstream passage. Resident fish species include bluegill, largemouth bass, smallmouth bass, carp, chain pickerel, brook trout, brown trout, rainbow trout, golden shiner, pumpkinseed, white sucker, and brown bullhead.

The project lands consist of less than one acre. The area surrounding the project is urban-developed and the reservoir shoreline is steep and rocky with walled sides. No lands of significant ecological value exist in the project area due to urban location and very small footprint.

No threatened or endangered species are potentially present in the project vicinity. Consultation with CTDEEP has confirmed that no listed species are present, and it is unlikely that any transient species may be found in the project area due to its urban location.

Via consultation with the State Historic Preservation Office, it was determined that the project does not have any impact on any cultural or historic resources.

Recreational resources at the project include informal fishing access. The project area is very small and surrounded by development. Public access is provided free of charge.

Compliance Status

There are no facility-specific conditions in the current Certificate

2024: No material changes or compliance issues were identified. The project remains in compliance based on the annual review.

2023: No material changes or compliance issues were identified. The project remains in compliance based on the annual review.

2022: No material changes or compliance issues were identified. The project remains in compliance based on the annual review.

2021: There were no reported changes or compliance issues. The project remains in compliance based on the annual review.

2020: There were no reported changes or compliance issues. The project remains in compliance based on the annual review.

2019: There were no reported changes or compliance issues. The project remains in compliance based on the annual review.

2018: There were no reported changes or compliance issues. The project remains in compliance based on the annual review.

2017: Annual reporting for the current Certificate has not yet taken effect.

Certification History

January 1, 2022: The LIHI Certificate term has been extended in accordance with Revision 2.05 of the LIHI 2nd Edition Certification Handbook issued January 1, 2022. Refer to the facility table above for the new term.

June 21, 2017: Having received no requests to appeal the preliminary certification decision for the Putnam Hydroelectric Project, the project received final certification as of June 17th, 2017.

May 17, 2017: The Low Impact Hydropower Institute has issued a Preliminary Certification Decision that the Putnam Hydroelectric Project (FERC No. P-5645) continues to satisfy the LIHI Certification Criteria. As provided for in Section 4.2.5 of the LIHI 2nd Edition Handbook, the Preliminary Certification Decision, along with the Application Reviewer’s report and (if prepared) report of the Executive Director, will be posted on the Institute’s Web page for 30 days.  Notice of the posting will be provided to all individuals or organizations that commented on the initial Application Package. Any Commenter may submit a letter to the Executive Director requesting an appeal within the 30-day period.  The appeal request must state specific reasons why the hydropower facility should have failed one or more criteria.  Only individuals or organizations that commented on the initial Application Package may file an appeal.  Further information about the LIHI appeal process is available in the LIHI Handbook, available at If no appeal is requested within the 30-day period, the Executive Director will issue LIHI Certification for the facility and post a notification of certification on the Institute’s website.  Once final, the effective certification date for the Putnam Project is April 10, 2017 for a five (5) year term, which will expire on April 10, 2022.

March 13, 2017: The Low Impact Hydropower Institute has received a complete application for a new term of Low Impact Certification for the Putnam Hydroelectric project. The application materials can be found in the Files section below. LIHI is seeking public comment on this application.  Specifically, we are interested in knowing whether you think the Putnam project meets the LIHI Low Impact Certification Criteria, as revised in the 2nd Edition Handbook released in March 2016.  Please review the program and criteria in LIHI’s revised Handbook and then review the Project’s 2016 application materials posted on the project page. 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 “Putnam Project Comments” in the subject line, or by mail addressed to the Low Impact Hydropower Institute, PO Box 194, Harrington Park, New Jersey 07640.  Comments must be received at the Institute on or before 5 pm Eastern time on May 12, 2017 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.

March 1, 2017: The Putnam Hydroelectric Project has been granted an extension of the current certificate term. The new expiration date is June 30, 2017. See the extension letter for explanation below.

August 9, 2012: The Putnam Hydropower Project has been certified for a third five year term, effective April 10, 2012 and expiring April 10, 2017.

April 10, 2007: The Putnam Hydropower Project continues to meet LIHI’s certification criteria, and has been certified for a second five year term, effective April 10, 2007 and expiring April 10, 2012.

April 10, 2002: The Putnam Hydropower Project is the first hydropower dam in New England to earn Low Impact Certification, meeting all of LIHI’s environmentally rigorous criteria. The certification is effective April 10, 2002 for five years, expiring April 10, 2007.

Certification Files

2017 Recertification

2012 Recertification

2007 Recertification

2002 Certification

Key documents