watershed map

Watershed map

The MWRA supplies wholesale water to local water departments in 50 communities, primarily in the Boston metropolitan area. On average, MWRA supplies approximately 200 million gallons per day to its water system customers. MWRA’s water comes from the Quabbin Reservoir, about 65 miles west of Boston, and the Wachusett Reservoir, about 35 miles west of Boston. Both Quabbin and Wachusett Reservoirs are man-made reservoirs, constructed for water supply purposes. More than 50% of the inflow into the Wachusett Reservoir is transferred from Quabbin Reservoir via the Quabbin Aqueduct/Tunnel. From Wachusett Reservoir, the Cosgrove Aqueduct conveys water to the John J. Carroll Treatment Plant (JJCWTP) in Marlborough. After treatment, water is sent eastward via the MetroWest Tunnel or Hultman Aqueduct (back-up).

Project Name Loring Road
LIHI Certificate Number 56
LIHI Effective and
Expiration Dates
April 14, 2015
April 14, 2023
Owner Massachusetts Water Resource Authority
State Massachusetts
Location Located in a valve chamber at the Loring Road Covered Storage Facility in Weston, Massachusetts.
Installed Capacity 200 kW
Average Annual Generation 1,200,000 kWH
Facility Type
FERC No. 13400

Downstream of JJCWTP and close to its centers of demand, MWRA has recently constructed a new network of tanks to protect and store treated drinking water in compliance with the Federal Safe Drinking Water Act. The network of new tanks includes the Norumbega and Loring Road Covered Storage Facilities. From the tanks, water is then distributed to member communities.

The MWRA transmission system consists of over 100 miles of tunnels and aqueducts that transports water largely by gravity to points of distribution within the MWRA service area. There are three locations within this water transmission system where hydroelectric facilities are located. These include: Oakdale at the end of the Quabbin Aqueduct; the Cosgrove Intake to the Cosgrove Aqueduct, and at the Loring Road Covered Storage Facility (this facility is under construction and will become operational in fall, 2010)

The Loring Road Small Conduit Hydroelectric Facility will be located in a valve chamber at the Loring Road Covered Storage Facility in Weston, Massachusetts. The hydroelectric facility, now under construction (projected completion is Fall, 2010) will generate power from fully treated potable water as it is transferred via a pipeline from one water supply storage tank in MWRA’s water distribution system (Norumbega) to another storage tank (Loring Road). The Loring Road Hydroelectric Project consists of one generating unit having an installed capacity of 200 kW. The MWRA estimates that the project would have an average annual generation of 1,207,000 kW-hours that would be used on-site and any excess would be sold to a local utility. The Loring Road Hydroelectric Project is located within the MWRA’s water distribution system. From Wachusett Reservoir (about 30 miles northeast of the proposed project’s location), water passes through the Cosgrove Aqueduct, to a water treatment plant, and then via the MetroWest Tunnel to the Norumbega Covered Storage Reservoir. The water continues through a branch of the Metro West tunnel to a underground valve chamber at Loring Road, where it runs through pressure-reducing valves to reduce the hydraulic pressure of the water. Under typical operation, the turbine generator will replace the function of the pressure reducing valves in the first valve chamber. After valve chamber one, the water flows through a second valve chamber that directs the flows to one of two storage tanks at Loring Road. From the tanks, the water discharges into downstream water pipelines. The turbine/generator will regulate flow and provide a constant pressure, in addition to energy recovery. FERC granted a conduit exemption for the Loring Road hydroelectric facility (FERC # 13400).

 Certification History

December 7, 2015: LIHI Executive Director Michael J. Sale, using authority delegated from the LIHI Governing Board, has certified that the Loring Road Hydroelectric Project (FERC No. P-13400) continues to satisfy the LIHI Certification Criteria. A Preliminary Decision was announced on December 14, 2015, and a 30-day appeal period was open through January 14, 2016. No requests for appeal were received.

The effective certification date for the Loring Road Project is April 14, 2015 for an eight (8) year term, which will expire on April 14, 2023.

October 22, 2015:  The Loring Road Hydroelectric Project has been granted an additional extension; the new expiration date is December 31, 2015.

September 30, 2015 – The Low Impact Hydropower Institute received a complete application for a new term of Low Impact Certification for the Loring Road Hydroelectric project on September 21, 2015.  The application materials can be found in the Files section below.

The public comment period for this application closed on November 30, 2015.

June 19, 2015: The Loring Road Hydroelectric Project has been granted an extension of the current certificate term. The new expiration date is October 11, 2015. See ExtensionLetter_2015Recert for explanation below.

July 21, 2010: The Loring Road Hydroelectric Project has been certified as low impact. Because construction of the Loring Road facility is not expected to be complete until fall of 2010, LIHI certification is granted for an 18 month term beginning on April 14, 2010, with the certification extended for an additional 42 months should the applicant demonstrate to LIHI that it has complied with the conditions contained in the FERC exemption.

June 14, 2010: The public comment period on the application for certification has been closed.

June 9, 2010: LIHI received a comment letter from the USFWS on the Loring Road project. It can be read in the Files section below.

May 4, 2010: LIHI received a comment letter from Dr. David Westerling, P.E. of the Department of Civil Enginerring at Merrimack College. It can be found in the Files section below.

April 14, 2010: The Massachusetts Water Resources Authority has submitted an application for the certification of the Loring Road Hydro Project. A public comment period will remain open for 60 days.


Files: