LIHI Certificate #90 - Deerfield River Project, Vermont and Massachusetts

The Deerfield River Project is located on the Deerfield River in southwestern Vermont and northwestern Massachusetts. The project is comprised of 8 dams and 7 hydroelectric stations, three of which are in Vermont, five of which are in Massachusetts. The Deerfield River mainstem and its tributaries can all be characterized as shallow, rapid flowing “flashy” mountain streams. The project encompasses about 66 miles of the river. The headwaters of the Deerfield River are in the Green Mountains of Vermont where land usage is primarily forest land. The lower (Massachusetts) river basin contains prominent features including rocky and stony hills and narrow steep-sided valleys. The only major urbanized region in the river basin is Greenfield, Massachusetts located at the confluence of the Deerfield and Connecticut Rivers.

The project includes eight developments, listed from upstream to downstream on the Deerfield River. The developments were constructed between 1911 and 1924, the Deerfield No. 5 hydro station was reconstructed at a slightly different location in 1974:

  • Somerset – The Somerset Development is located on the East Branch of the Deerfield River. It consists of a storage reservoir, dam, outlet works and spillway. This impoundment is operated as a seasonal storage facility. There are no power generating facilities. Somerset Reservoir has a surface area of roughly 1,514 acres, gross storage of 57,345 acre-feet, and 20,614 acre-feet of usable storage. The earthfill dam is about 110 feet high and 2,101 feet long. Water can be conveyed from the reservoir at two locations. The main outlet works, located in the gatehouse at the eastern end of the dam has two gated 48-inch-diameter pipes used to control reservoir discharge and minimum flow. There is also a side channel spillway with 3-foot flashboards located at the western end of the dam. The spillway channel is about 800 feet long, 45 feet wide, and from 6 to 30 feet deep. This spillway is used only for extreme flood events.
  • Searsburg – The Searsburg Development is the first development on the mainstem of the Deerfield River, approximately 11 miles downstream of its headwaters, and is the point of confluence with the East Branch. The development is operated on a peaking, daily storage basis. It consists of an earthfill dam and spillway, intake and penstock, powerhouse, and substation. Searsburg Reservoir is roughly 0.9 miles long and 0.16 miles across at its widest point. It has a surface area of 30 acres, 412 acre-feet of gross storage and 197 acre-feet of useable storage. Searsburg Dam is an earthfill structure about 50 feet high and 475 feet long with a 137-foot-long concrete gravity spillway, penstock intake gate, and sluice gate in the south abutment. Water is conveyed by either the overflow spillway, the 6-foot by 8-foot sluice gate, or the penstock, which leads to the powerhouse housing one vertical 5 MW Francis unit. The intake facility includes a penstock intake gate with an 8-foot-diameter wood stave conduit that runs 18,412 feet to a steel differential surge tank 50 feet in diameter and 34 feet high, and a steel penstock 6.5 feet in diameter and 495 feet long that leads from the surge tank to the powerhouse. The dam and conduit create a bypassed reach approximately 3.5 miles long.
  • Harriman – The Harriman Development is operated on a peaking, seasonal storage basis. The facility consists of a storage reservoir, an earthfill dam, a “morning glory” spillway, intake, conveyance tunnel and penstocks, powerhouse, and substations. Harriman Reservoir is approximately 9 miles long and 0.78 mile across at its widest point and has a surface area of 2,039 acres. It has a maximum depth of 180 feet and a useable drawdown of 86 feet. It has 103,375 acre-feet of useable storage and 117,300 acre-feet of gross storage. Harriman Dam is an earthfill dam 215.5 feet high and 1,250 feet long. The “morning glory” spillway is normally equipped with 6 feet of flashboards. A 21.5-foot-high horseshoe shaped tunnel discharges water from the spillway to the downstream channel. There is also a 4-foot-diameter pipe that leads from the original construction’s diversion tunnel to the morning glory spillway tunnel. In 1998 the outlet pipe was modified to hold a 14-inch-diameter fixed cone discharge valve used to discharge the minimum flows into the 4.4-mile-long bypass reach. The flow of water to the powerhouse intake is controlled by two 8-foot-diameter valves. Water is conveyed through these valves to the powerhouse via a 12,812-foot long, 14-foot-diameter concrete lined horseshoe shaped tunnel, a steel differential surge tank 34 feet in diameter and 184 feet high, and three steel 620-foot-long, 9-foot-diameter penstocks to three Francis units of 13.7 MW each.
Project Name Deerfield River
LIHI Certificate No. 90
LIHI Certificate Term April 25, 2020 - April 24, 2030
Owner Great River Hydro, LLC
State Vermont, Massachusetts
Location The project consists of eight developments, located between river mile 13.2 and 66 in Bennington and Windham Counties in Vermont, and in Berkshire and Franklin Counties in Massachusetts; the project area encompasses about a 65-mile reach of the Deerfield River.
Installed Capacity Total 86 MW (audited) Searsburg: 5 MW; Harriman: 41 MW; Sherman: 6 MW; Deerfield No. 5: 14 MW; Deerfield No. 4: 6 MW; Deerfield No. 3: 7 MW; Deerfield No. 2: 7 MW
Annual Generation 260,275 MWh total (10 year average)
Facility Type Somerset: no hydropower generation Searsburg: peaking, daily storage Harriman: peaking, seasonal storage Sherman: peaking, weekly storage Deerfield No. 5: peaking, daily storage Deerfield No. 4: peaking, daily storage Deerfield No. 3: peaking, daily storage Deerfield No. 2: peaking, daily storage
FERC No. P-2323 issued 1997, expires 2037
  • Sherman – The Sherman Development is operated on a peaking, weekly storage basis. The facility consists of an earthfill dam and spillway, intake and penstock, powerhouse, and substation. Sherman Reservoir is roughly 2 miles long and 0.25 miles across at its widest point with a surface area of 218 acres, 1,359 acre-feet of useable storage and gross storage of 3,593 acre-feet. The impoundment also formerly provided once-through cooling water for the now decommissioned Yankee Atomic Electric Power Company’s Rowe Station. Sherman Dam is 110 feet high and 810 feet long with a 179-foot-long concrete gravity spillway and a concrete and brick intake structure. Four feet of flashboards are maintained on the spillway year-round. Water is conveyed from the reservoir either through spillage, or via the powerhouse intake. Water is conveyed to the integral powerhouse via a concrete conduit 98 feet in length with a cross-sectional area of 142 square feet, and a steel penstock 13 feet in diameter and 227 feet long. There are no diversion canals or tunnels. The powerhouse contains one vertical 6 MW Francis unit.
  • Deerfield No. 5 – The Deerfield No. 5 Development is operated on a peaking, daily storage basis. The facility consists of two dams, a series of diversion tunnels, canals and penstocks, the powerhouse, and a substation. The impoundment is about 0.75-mile-long and 180 feet across at its widest point with a surface area of 38 acres, and gross storage of 118 acre-feet. It is comprised of a concrete gravity spillway 35 feet high and 90 feet long; a concrete intake structure that directs water to a minimum flow pipe; two low level sluice gates; and a power tunnel located in the west abutment. Water is conveyed from the impoundment by spillage, the minimum flow pipe, the sluice gates, or by the intake tunnel to the powerhouse. Hydraulically controlled steel flap gates are used to maintain normal reservoir elevation along the entire spillway crest. The control gates in the western abutment intake structure are composed of two 8-foot-wide by 7.75-foot-high sluices and a single 12.5-foot by 13-foot intake gate. Two tunnels, two concrete conduits, and three canals crisscross River Road and total 14,941 feet in length. The Deerfield No. 5 tunnel/canal system includes a small concrete gravity diversion structure about 12 feet high and 160 feet long on Dunbar Brook which directs water from the impounded brook (approximately 0.1-mile long and 175 feet across) into the southernmost tunnel. Collectively, these structures create a 3-mile-long bypassed reach and convey water from the dam to a 400-foot-long, 10-foot-diameter steel penstock and then to the powerhouse. The powerhouse is a steel frame and concrete structure constructed in 1974. It replaced the original station which was removed when the Bear Swamp Pumped Storage Project (FERC No. 2669) was built. The powerhouse contains one vertical Francis unit with a capacity of 14 MW. The Dunbar Brook diversion structure was completely redesigned and reconstructed in 1993. Two gates control water level in the canals and can divert flow to the powerhouse or release water into the Deerfield River via Dunbar Brook.
  • Deerfield No. 4 – The Deerfield No. 4 Development is operated on a peaking, daily storage basis. The facility consists of an earthfill dam, spillway and sluice gates, intake and tunnel, forebay and penstocks, powerhouse, and substation. The impoundment is roughly 2 miles long and 500 feet across at its widest point, with a surface area of 75 acres, gross storage of 467 acre-feet and usable storage of 432 acre-feet. The dam is comprised of an earthfill embankment with a concrete core approximately 50 feet high and 160 feet long, a 241-foot-long concrete gravity spillway, and three sluice gates located in the east abutment. The dam is equipped with flashboards ranging in height from 6 to 8 feet. Water is conveyed from the impoundment either by spillage or by sluice gates located in the eastern abutment. The intake gates include a 10-foot by 10-foot, an 8-foot by 10-foot, and a single 10-foot by 14-foot surface sluice. In addition, a 6-foot by 12-foot surface sluice gate is located adjacent to, and downstream of, the power tunnel intake racks. This gate discharges into a 10-foot-diameter vertical conduit which in turn, discharges into a 4-foot-diameter pipe that discharges into the tailrace. It has an electric operator used to pass minimum flows into the 1.5-mile-long bypassed reach and was formerly used for downstream fish passage. The power tunnel conveys water from the intake structure at the impoundment via a 12.5-foot-diameter, 1,514-foot-long concrete and brick lined horseshoe shaped tunnel that leads to the powerhouse forebay. The earthen forebay has a 12,000 square foot surface area and a 35-foot depth. From the forebay, water is conveyed through three 10-foot-diameter, 154-foot-long steel penstocks to the powerhouse. The powerhouse is a steel frame and brick structure constructed in 1913. It contains three horizontal Francis units each with a capacity of 2 MW.
  • Deerfield No. 3 – The Deerfield No. 3 Development is operated on a peaking, daily storage basis. The facility consists of a concrete gravity dam and sluice gates, intake, tunnel, forebay and penstocks, powerhouse, and substation. The impoundment is roughly 1.3 miles long and 300 feet across at its widest point with a surface area of 42 acres, 221 acre-feet of gross storage and 200 acre-feet of useable storage. The dam is composed of a concrete gravity spillway approximately 15 feet high and 475 feet long equipped with 6-foot flashboards, two sluice gates and a power tunnel intake located in the south abutment. The sluice gates in the south abutment include a 10-foot-wide surface sluice and an 8-foot-wide by 4-foot-high submerged sluice. A six-foot by 10-foot surface sluice gate, located adjacent to, and downstream of the power tunnel intake racks, discharges directly into the tailrace. This gate has an electric operator and is used to pass minimum flows into the 0.2-mile-long bypassed reach and was formerly used for downstream fish passage. The power tunnel exiting the gated intake is a 677-foot-long, 17-foot-wide by 12.5-foot-high concrete conduit. It runs underground to an 880-foot long forebay from which water is conveyed via three 59-foot-long, 10-foot-diameter steel penstocks to the powerhouse. The powerhouse is a steel frame and brick structure built in 1912. It contains three horizontal Francis units each with a capacity of 2.3 MW. The tailwater for Deerfield No. 3 is formed by the headwaters of the Gardner’s Falls Project impoundment (LIHI #80). The Deerfield No. 3 powerhouse discharges into an impounded section of the river even when Gardner’s Falls is maintained at its lowest level.
  • Deerfield No. 2 – The Deerfield No. 2 Development is operated on a peaking, daily storage basis. The facility consists of a concrete gravity dam and sluice gates, an inflatable bladder, trip-able flashboards, intake and penstocks, powerhouse, and substation. The impoundment is roughly 1.5 miles long and 500 feet across at its widest point with a surface area of 63.5 acres, 550 acre-feet of gross storage and 500 acre-feet of useable storage. The dam consists of a concrete gravity spillway approximately 70 feet high and 447 feet long, with the inflatable bladder and trip-able flashboards, sluice gates and an integral powerhouse located at the western end of the spillway. Water can be conveyed from the impoundment by spillage, sluice gates, or through the powerhouse. Ten feet of trip-able flashboards on top of the spillway crest and the inflatable bladder (112 feet long by 10 feet high) are used to maintain normal impoundment elevation. When water is at the top of the bladder, it will deflate automatically if inflow exceeds the powerhouse discharge. The two surface sluices are each 10 feet wide. A six-foot by 16-foot surface sluice gate is located between the two 10-foot-wide sluices and the inflatable bladder. It discharges directly into the tailrace, downstream of the dam. This gate has an electric operator and was formerly used for downstream fish passage. The powerhouse, constructed in 1913, is integral to the dam, and includes a gated intake structure with three steel 11-foot-diameter by 35-foot-long penstocks. The powerhouse contains three horizontal Francis units each with a capacity of 2.3 MW.

Each development operates in a different operational mode. Most operate as peaking facilities with varying amounts of storage (i.e., seasonal, weekly, or daily). Additionally, the seasonal and weekly storage project facilities limit impoundment elevation changes (except for Sherman reservoir) and all projects have minimum flow requirements. These requirements were developed to support fisheries and wildlife resources in the area as well as maintain state water quality standards. The minimum flows and other requirements of the facilities are explained further in the 2021 Recertification Report found in the Files section below.

Waters within the project reach are located in Vermont and Massachusetts, each of which has different standards of water quality classification. For the facilities located in Vermont, the water classifications are designated as Class A (1) and B (1) in terms of aquatic habitat and Class A(2) and B(2) for aquatic habitat or recreation. These designations indicate that the waters are managed to support aquatic biota, wildlife, and flora, as well as fishing, primary contact recreation, and as a public water source. The Somerset Reservoir, East Branch Deerfield River below Somerset Dam, Searsburg Reservoir, Upper Deerfield River below Searsburg Dam, Harriman Reservoir, and the Vermont portion of Sherman Reservoir are impaired for mercury in fish tissue due to polluted runoff and from atmospheric deposition. The Somerset Reservoir is also listed as impaired for pH due to atmospheric deposition. The Massachusetts waters are designated as Class B, best suited for aquatic biota and habitat, primary and secondary contact recreation, and public water supply. The lower Massachusetts portion of Sherman Reservoir is listed as impaired for mercury in fish tissue, and two contiguous sections from the confluence with the North River to the confluence with the Connecticut River below Deerfield No. 2 are listed for E. coli contamination. The mercury impairment is due to atmospheric deposition and E. coli contamination is caused by municipal point source discharges, combined sewer overflows, and stormwater runoff. Neither impairment is contributed to by the project.

The lower Deerfield River presently supports migratory fish species including American shad, blueback herring, sea lamprey, American eel, and shortnose sturgeon. The states of Vermont and Massachusetts both stock trout species in the project area. Vermont stocks brown and brook trout in the mainstem of the Deerfield River, brook trout in the Somerset and Searsburg reservoirs, brown trout in Sherman reservoir, and Harriman reservoir supports brook, brown, rainbow, and lake trout. The Massachusetts portion of the river is stocked with brown, brook, and rainbow trout at various locations. Other resident fish species reported to occur in the upper Deerfield River include blacknose dace, bluegill, brown bullhead, chain pickerel, common shiner, creek chub, fallfish, golden shiner, largemouth bass, longnose dace, longnose sucker, mimic shiner, pumpkinseed, rainbow smelt, rock bass, slimy sculpin, smallmouth bass, white sucker, and yellow perch.

The project lands consist of over 17,700 acres and are largely undeveloped and protected by perpetual conservation easements. These areas are managed for multiple uses including high quality timber, passive recreation, and wildlife resources. The lands provide wildlife habitat, protections for the natural resources therein, as well as scenic and recreational access.

PLUS-Standard: The project owner established the Deerfield River Basin Environmental Enhancement Fund to finance watershed conservation, recreational and educational opportunities, and the maintenance and monitoring of such activities. Additionally, the conservation lands in the project area cover well over 50% of project owned lands.

Threatened or endangered species potentially present in the project vicinity include the common loon, tubercled orchid, Northern long-eared bat, little brown bat, tricolored bat, American bittersweet, muskflower, sandbar cherry, and bald eagle.

The common loon has seen a dramatic population increase and the project owner has continued to collaborate with Vermont Department of Fish and Wildlife (VDFW) to support the nesting activities of the species within the project boundary. The orchid species was present in the Searsburg and Harriman bypassed reaches and an increase in minimum flows in the late 1990s threatened the existence of the species. The project owner implemented a plan that relocated the species and monitored the health of the population after the relocation. VDFW has commended the success of such work and the orchid population has successfully repopulated the area. Periodic tree trimming and maintenance have the potential to impact the Northern long eared bat. VDFW is consulted to ensure no adverse impacts to bat roosting habitat. The project coordinates with Massachusetts Division of Fisheries and Wildlife to minimize impacts to the listed plant species.

PLUS-Standard: The project owner has implemented a comprehensive operations and management compliance plan under the Massachusetts Natural Heritage Endangered Species Program. The plan specifies routine operations and maintenance tasks, maps Project areas and the activities that occur within each area, discusses avoidance and minimization of impacts to threatened, endangered and rare species, and priority habitats. The plan identifies control measures in place to mitigate. Areas of impact are minimized, approved methods are employed, and updated tools and techniques are used. Erosion and siltation control measures are used as needed to protect regulated resources. Timing restrictions or seasonal work windows may be developed if there are any species-related requirements.

The hydroelectric facilities which comprise the project are all eligible for listing on the National Register of Historic Places. The properties that contribute to its eligibility include 27 historic sites including nineteenth and twentieth century residences, mill/factory complexes, mining complexes, schoolhouses, bridge abutments, and a cemetery. A cultural resources management plan was developed in consultation with the Vermont and Massachusetts State Historic Preservation Offices and the Advisory Council on Historic Preservation. The plan includes mitigation measures to preserve and protect the historic features at the project.

Recreational resources at the project include 16 trails, 15 picnic areas, eight boat launches, four carry-in/out access areas, one angler access area, and whitewater put-in and take-out facilities. Whitewater releases from Deerfield No. 5 Dam are scheduled each year. The project also has online and telephone access listing the anticipated flow release schedules for the following day. Real-time information is also provided in 10-minute intervals. Public access is provided free of charge except where safety concerns preclude access.


Certification History

June 3, 2021: The decision to recertify the Deerfield River Project became final after the close of the appeals period on May 28, 2021 with no appeals filed. The Certification term is from April 25, 2020 – April 24, 2030. The certification includes four conditions:
  • Condition 1: If the USF&WS or state resource agencies request upstream and/or downstream American eel passage facilities at the Project during the certification term, the Project Owner shall notify LIHI within 60 days of the request(s). LIHI will review the request to determine whether it meets the LIHI definition of “science-based agency recommendation”. If so, the Project Owner shall initiate consultation with the relevant agency(ies) within 90 days to develop a mutually acceptable plan and schedule for phased implementation at one or more of the Project developments. The Project Owner shall provide LIHI with documentation that includes a description of the passage facility(ies), any additional protection measures, and the implementation schedule for design, installation, and operation. The agreement, and subsequent status of passage implementation, shall be provided to LIHI in annual compliance statements.
  • Condition 2: By April 30, 2022, the Project Owner shall provide and maintain information on available recreation opportunities at the Project on the company website including but not limited to one or more maps showing the locations and types of facilities as well as additional information such as permissible times of use and both permissible and restricted activities (if appropriate). The annual whitewater release schedule for Deerfield No. 5 Dam will also be posted to the website as well as links to anticipated and real-time flow information below Project dams. The Project Owner shall post and maintain conspicuous signs, where permissible, at access points that identify and direct people to project recreation facilities. The status of these actions shall be reported to LIHI in the annual compliance submittal in 2022.
  • Condition 3: The Owner shall provide a status update of the Deerfield No. 5 minimum flow unit installation and initial operation in the first annual compliance statement after the unit becomes operational. The update shall identify any deviations from the expected design or operating conditions approved by FERC. LIHI reserves the right to require additional information and conduct additional review of impacts if changes in design or operation occur that could affect one or more LIHI criteria.
  • Condition 4: In order to retain the PLUS standard for Threatened and Endangered Species, the Owner shall report to LIHI within 60 days of any instances of non-compliance or any agency compliance concerns with the Massachusetts NHESP Operations and Management Compliance Plan (NOMCP). The Owner shall also report within 60 days if the NOMCP is no longer in effect. In either event, LIHI will review the information and determine if the PLUS award is still applicable.

April 28, 2021: The Low Impact Hydropower Institute (LIHI) has preliminarily approved recertification of the Deerfield River Project for a new 10-year term of Low Impact Certification.

This decision is preliminary pending the 30-day appeal window. Only those who commented on the initial application during the 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 by email to comments@lowimpacthydro.org with "Deerfield River Project” in the subject line, or by mail addressed to the Low Impact Hydropower Institute, 1167 Massachusetts Ave, Arlington MA 02476. All requests will be posted to the website. The applicant will have an opportunity to respond and any response will also be posted.Requests must be received by 5 pm Eastern time on May 28, 2021. The application and reviewer's report are available below.

If no appeal requests are received and the decision becomes final, the Certification term for the Project will be April 25, 2020 through April 24, 2030.

November 30, 2020: The Low Impact Hydropower Institute has received a complete application for Low Impact recertification of the Deerfield River 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 comments@lowimpacthydro.org with “Deerfield River 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 January 29, 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.

May 15, 2016: LIHI has received notice that TransCanada Hydro Northeast Inc. was converted to a limited liability company on April 7, 2017, becoming TransCanada Hydro Northeast LLC.  On April 19, 2017, the name of the company was changed from TransCanada Hydro Northeast LLC to Great River Hydro, LLC.

September 15, 2012: The Deerfield River Project has been certified as low impact for an eight year term, effective April 25, 2012 and expiring April 25, 2020.  This Certification is issued with the following specific conditions:

  • Condition 1:If the U.S. Fish and Wildlife Service or the State of Massachusetts requests upstream and/or downstream eel passage facilities at the Project, the Project owner shall so notify LIHI within 30 days and shall enter into, and provide LIHI with a copy of, an agreement reached among the Project owner, the U.S. Fish and Wildlife Service, and/or the State of Massachusetts to provide both interim (if requested by a Resource Agency) and permanent safe, timely, and effective passage for American eel. The Agreement must be finalized within 120 days of the request for passage and must include a description of the planned passage and protection measures and the implementation schedule for design, installation, and operations. The agreement shall be filed with LIHI within 30 days of its execution.
  • Condition 2:If the State of Vermont requests modification of the Project or its operation at Harriman Dam to address temperature and/or dissolved oxygen concerns pursuant to Article 415 of the Project FERC license, the Project owner shall so notify LIHI within 30 days and shall enter into, and provide LIHI with a copy of, an agreement reached among the Project owner and the State of Vermont to address those concerns. The Agreement must be finalized within 120 days of the request for Project modification and must include a description of the planned measures and the implementation schedule for those measures. The agreement shall be filed with LIHI within 30 days of its execution.

April 25, 2012: TransCanada Hydro Northeast has resubmitted their application for certification of the Deerfield River Project. They had originally filed for low impact certification in December of 2009 but withdrew in August of 2010 when several issues of concern were identified by the Application Reviewer.

December 31, 2009: TransCanada Hydro Northeast submitted an application for certification of the Deerfield River project.