LIHI Certificate #55 - Cosgrove Project, Massachusetts

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).

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.

The Cosgrove hydroelectric facility is located at the Cosgrove intake. The Cosgrove Intake and hydroelectric facility regulates the flow of water from the Wachusett Reservoir into the Cosgrove Aqueduct, which is an important transmission leg in the supply of water to the Boston Metropolitan area.   There are two sections, the North and South intakes, and both intakes include a hydraulic turbine and two bypass lines. Each intake has three channels with traveling water screens. Each intake also has an upper intake sluice gate and lower intake sluice gate that allow operational flexibility to draw water from different levels of the reservoir. On the North intake, after this sluice gate, the water enters a common wet-well and from the wet well, flow is directed to either the turbine generator 1, bypass line 1 or bypass line 2 or a combination. Each of the bypass lines contains a sleeve valve, which is designed to regulate flows to the water supply transmission system over a range of flows. The configuration of the South intake parallels the North intake and flows entering the South intake are directed to either turbine generator 2, or bypass line 3 or bypass line 4.

Turbines are vertically oriented, full Kaplan type with six adjustable runner blades. The turbine generators were put into operation in 1969, and were recently rehabilitated and upgraded. These upgrades were necessary to integrate the turbines operation with a newly configured water supply system. The hydroelectric facility now operates at a head of approximately 55 feet, which flows through each turbine varying from 60 mgd to 280 mgd. Maximum output of each of the turbines is between 1000-1200 kW. Average annual power generation is 4.6 Gigawatt hours.  Electricity is used on site as well as exported to the electrical grid (National Grid).

Project Name Cosgrove
LIHI Certificate No. 55
LIHI Certificate Term April 14, 2015 - April 14, 2023
Owner Massachusetts Water Resource Authority
State Massachusetts
Location Located at the Cosgrove Intake.
Installed Capacity 2.4 MW
Average Annual Generation 4,656 MWh
Facility Type conduit
FERC No. P-10688 exempt 1990

Certification History

January 13, 2016: LIHI Executive Director Michael J. Sale, using authority delegated from the LIHI Governing Board, has certified that the Cosgrove Hydroelectric Project (FERC No. P-10689) 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 Cosgrove Project is April 14, 2015 for an eight (8) year term, which will expire on April 14, 2023.

October 22, 2015:  The Cosgrove 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 Cosgrove 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 Cosgrove Hydroelectric project has been granted an extension of the current certificate term. The new expiration date is December 31, 2015. See ExtensionLetter_2015Recert for explanation below.

July 21, 2010: The Cosgrove Hydroelectric Project has been certified as low impact for a five year term, effective April 14, 2010 and expiring April 14, 2015.

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 regarding the Cosgrove Project. It can be read in the Files section below.

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