LIHI Certificate #121 – Lawrence Project, Massachusetts

March 24, 2020 – COVID-19 update: Central Rivers Power has notified LIHI that the Lawrence 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 Lawrence Project is located on the Merrimack River in the city of Lawrence, Essex County, Massachusetts. The Project works consist of: (1) a 33-foot high, 900-foot-long dam of rubble masonry construction with five-foot-high inflatable flashboard system; (2) a 9.8-mile-long reservoir having a surface area of 655 acres at normal high water elevation 44.17 feet mean sea level (msl) and a maximum storage capacity of approximately 19,900 acre-feet; (3) the existing South Canal approximately 35 feet wide and 10 feet deep, originating at the south abutment of the Essex Dam and generally paralleling the Merrimack River bed, below the Essex Dam, for a distance of approximately 2,750 feet; (4) the existing North Canal, approximately 95 feet wide and 15 feet deep, originating at the north abutment of the dam and paralleling the Merrimack River below the dam for a distance of approximately 5,300 feet; (5) fish passage facilities including a fish elevator installed at the dam, a downstream fish bypass and an eel ladder; (6) a powerhouse containing two 8.4 MW hydroelectric generating units and a tailrace channel extending into the Merrimack River Channel; and (7) appurtenant facilities.

The Lawrence Project is operated in a run-of-river mode through use of an automatic pond level control (PLC). The upstream fish passage operation typically begins annually in late April and continues through mid-July and from mid-September through October, with final operation schedule determined in consultation with resource agencies. Upstream fish passage lifts generally occur between 8:00am to 4:00pm daily during the operational periods and maintains operations up to river flows of 25,000 cfs with a 120 cfs attraction flow provided for the fish elevator system. The downstream fish passage bypass operation typically begins annually on April 1 and continues through mid-July and from September 1 through November 15, with final operation schedule determined in consultation with resource agencies. The South Canal is closed annually during the spring and fall outmigration seasons.

The Lawrence Project’s dam is equipped with a pneumatic inflatable flashboard system. The system varies air pressure to adjust the flashboard height to maintain normal headpond elevation at the Project based on the river user needs, flow and weather conditions. The installation of the system eliminated the need for impoundment drawdowns required for flashboard replacement, enhanced river debris management with reduced debris build up near the dam, enhanced high flow condition management and reduced false fish attraction away from the fish passage facilities often caused by board leakage and partial board loss.

Project Name Lawrence
LIHI Certificate No. 121
LIHI Certificate Term March 13, 2015 - March 13, 2020, extended to July 31, 2021
Owner Essex Company, LLC a subsidiary of Central Rivers Power USA
State Massachusetts
Location Located at river mile 31 on the Merrimack River in the city of Lawrence, Essex County, MA.
Installed Capacity 16.8 MW
Average Annual Generation 64,600 MWh
Facility Type Run-of-river
FERC No. P-2800 issued 1978, expires 2028

Certification History

December 18, 2020: The Low Impact Hydropower Institute has received a complete application for Low Impact recertification of the Lawrence Hydroelectric Project. The complete application can be found below.

LIHI is seeking public comment on this application. 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 “Lawrence Project Comments” in the subject line, or by mail addressed to the Low Impact Hydropower Institute, 1167 Massachusetts Avenue, Arlington MA 02476. Comments must be received on or before 5 pm Eastern time on February 16, 2021 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.

July 1, 2015: Executive Director Michael J. Sale, using authority delegated from the LIHI Governing Board and a full review of the Application Reviewer’s report and all public comments and additional materials provided by the Applicant, has determined that the Lawrence Hydroelectric Project (FERC No. P-2800) satisfies the LIHI Certification Criteria. The effective certification date for the Lawrence Project is March 13, 2015 for a five (5) year term, which will expire on March 13, 2020, with the following project specific conditions:

  • Condition satisfied in 2016. Applicant will obtain a final letter from Massachusetts Department of Fish and Wildlife (or other agency recommended by MDFW) that confirms the facility and facility operations have no negative impact on the existence of Bald Eagle in the area, by August 1, 2015.
  • Condition satisfied in 2016. Applicant will work with MDFW to improve effectiveness of eel passage at the site by July 15, 2016. This includes keeping elvers off dam by eliminating or rerouting leakage. Applicant will obtain letter from MDFW by July 15, 2016 that confirms passage measures are adequate.