LIHI Certificate #142 – Lowell Project, Massachusetts

March 24, 2020 – COVID-19 update: Central Rivers Power has notified LIHI that the Lowell Project visitors center will remain closed until further notice.  The facility is only open by appointment, and the company will not accept any requests until it is safe to allow group access.

The Lowell Hydroelectric Project (FERC Project No. 2790) is located on the Merrimack River in the City of Lowell, Massachusetts. The Merrimack River watershed encompasses 5,010 square miles of land within the states of New Hampshire and Massachusetts and is the fourth largest watershed in New England. The Merrimack River originates at the confluence of two major rivers, the Pemigewasset and Winnipesaukee, in Franklin, N.H. From its origin, the river travels 115 miles to the Atlantic Ocean at Newburyport, Massachusetts. The Lowell Project is located at the second dam (Pawtucket Dam) on the mainstem at River Mile 41; Essex Dam is located ten miles downstream of the Lowell Project dam and is the site of another hydroelectric project (the Lawrence Hydroelectric Project, FERC Project No. 2800, LIHI #121.

Pawtucket Dam was originally constructed in 1847, with a second spillway section added in 1875 and is a 1,093 foot-long, 15 foot-high stone-masonry gravity dam that impounds a 720 acre reservoir. The expansion involved construction of a new powerhouse, the E.L. Field Powerhouse, on the Northern Canal; the new plant was brought on line in November 1985. Construction of the new plant included excavation of a 1,000-foot-long tailrace channel in ledge; the tailrace is separated from the river by a five-foot-high training wall. The license also authorized continued operation of four smaller power plants located in existing mill buildings on the canal system.  Combined, the five powerhouses have a capacity of 24.8 MW.  The canal system consists of two tiers, the Northern Canal, controlled by the gatehouse at the dam, and the Pawtucket Canal, controlled by the Francis Gate and Guard Locks.

The four power stations housed in historic mills are the Hamilton Station, 5 units drawing from the Hamilton Canal and discharging into the Lower Pawtucket Canal (1,180 kW); the Assets Station, 3 units drawing from the Merrimack Canal and discharging into the Lower Pawtucket Canal (795 kW); the Bridge Street Station, 3 units (a.k.a. Section 8) drawing water from the Eastern Canal and discharging into the Concord River (1,080 kW); and the John Street Station, 4 units drawing water from the Eastern Canal and discharging into the Merrimack River (2,100 kW).

Upstream and downstream fish passage facilities include a fish elevator and downstream fish bypass at the E.L. Field powerhouse, and a vertical-slot fish ladder at the Pawtucket Dam. The project maintains a minimum flow of 1,990 cfs downstream of the E.L. Field powerhouse by operating the project in run-of-river mode. Flows are provided seasonally in the bypassed reach below Pawtucket Dam for migratory fish passage. Flow control and habitat enhancement are being provided by a pneumatic crest gate which is due to be completed in 2018.

The Pawtucket gatehouse was constructed to control flow from behind the Pawtucket Dam into the Northern Canal. Notably, it was the site of the first Francis turbine which operated the ten wooden gates that controlled the flow of the Merrimack into the canal. Now the gates are electronically controlled.

Project Name Lowell
LIHI Certificate No. 142
LIHI Certificate Term August 23, 2017 - August 22, 2022
Owner Boott Hydropower, LLC, a subsidiary of Central Rivers Power USA
State Massachusetts
Location Merrimack River River mile 40.8
Installed Capacity 22.463 MW
Average Annual Generation 88,530 MWh
Facility Type diversion, run-of-river
FERC No. P-2790 issued 1983, expires 2023

Certification History

April 17, 2018 The 30-day appeal window closed for the preliminary certification decision of the Lowell Hydroelectric Project closed on April 11th, 2018 with no appeals to the decision received. The decision is therefore final and the Lowell Hydroelectric Project is LIHI Certificate #142. The Certificate term will be August 23, 2017 – August 22, 2022. The certificate includes the following conditions:

  • Condition 1:The Owner shall continue to maintain the current voluntary seasonal attraction flows in the bypass reach and full season fish ladder operation (See LIHI Reviewer Report, Appendix – Agency Letters) and proactively consult with the resource agencies regarding possible interim opportunities to enhance flows in the bypass reach and in the canal system (if needed) while the upcoming FERC relicensing activities are underway. Such opportunities may involve study of habitat quantity/quality, alternative flow regimes, and/or water quality monitoring so that modifications can be implemented more quickly once a new license is issued, or even prior to a new license if agreed to by all parties. During the term of this LIHI Certification, should a resource agency request implementation of enhanced bypass and/or canal flow measures as part of their recommendations or jurisdictional mandates under the relicensing proceedings, the Owner shall provide to LIHI in the annual compliance report a copy of the request, and describe the Owner’s plans to address these requests along with a schedule and progress toward implementation.
  • Condition 2. The Owner shall provide to LIHI as part of the annual compliance report, a status report of the FERC licensing progress listing significant agency interactions that have occurred in the past year that are relevant to any of LIHI’s Certification criteria, and highlighting major topics of agreement or disagreement. LIHI reserves the right to request additional details if necessary, if highlighted topics are relevant to LIHI Certification criteria and their associated goals. LIHI also reserves the right to modify the Certificate conditions again if needed.
  • Condition 3. The Owner shall work toward removing the state’s water quality impairment listing for hydromodification in the combined bypass and downstream reach of the Project. This may be accomplished by working proactively with Massachusetts DEP and: a) ensuring that any water quality studies conducted as part of relicensing adhere to state quality control/quality assurance (QA/QC) protocols and that results are submitted to the state timely and in the proper format for use by the state in its biennial review(s) of the State’s Clean Water Act Integrated List of Waters; b) providing results of other relicensing studies (e.g., instream flow studies) to the state for inclusion in upcoming biennial reviews of the state’s impairment listings; and c) by submitting public comments relative to results from flow and water quality studies in that reach during the public comment process when the state’s draft lists are made available. Activities and any changes in the impairment listing for the reach shall be summarized and reported to LIHI in the annual compliance reports.
  • Condition 4. The Merrimack River basin is highly developed for water resources and the operation of multiple hydropower facilities and other water uses in the basin are interconnected to a degree that requires a systematic approach for future management. Solutions for individual facilities are insufficient to achieve the environmental protection and restoration needed for long-term, sustainable water uses. Therefore, the Owner of the Lowell facility shall continue to play a constructive, supportive role in promoting integrative water management in the basin, both in the Project’s upcoming FERC relicensing and in other regulatory proceedings and voluntary activities that may develop in the basin. The Owner shall report to LIHI on its activities relative to this condition each year in its annual compliance report. LIHI reserves the right to modify the Certificate conditions again if needed.

March 12, 2018– On March 9, 2018, the Low Impact Hydropower Institute (LIHI) preliminarily approved Low Impact Certification for the Lowell project. The reviewer’s report and the report of the Executive Director are attached at the bottom of this page. This decision is preliminary pending the 30-day appeal window. Only those who commented in the initial application 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 to Requests must be received by 5:00 pm Eastern time April 11, 2018.

September 22, 2017 – On August 25, 2017, the Low Impact Hydropower Institute (LIHI) received a complete application from Enel Green Power North America, Inc. for the Low Impact Certification of the Lowell Hydroelectric Project, FERC No. 2790, located on the Merrimack River in Massachusetts.

LIHI is seeking comment on the Lowell application for certification. 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 “Lowell Project Comments” in the subject line, or by mail addressed to the Low Impact Hydropower Institute, 329 Massachusetts Avenue, Suite 2, Lexington, MA 02420.  Comments must be received at the Institute on or before 5 pm Eastern time on November 22, 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.