LIHI Certificate # 39 --- 15 Mile Falls Project (FERC No. 2077) Connecticut River, New Hampshire and Vermont (FERC No. 2077)
15-Mile Falls Hydro Project is the First TransCanada Project to Earn LIHI Certification
Portland, Maine (June 25, 2009)–The Low Impact Hydropower Institute (LIHI) announced today that TransCanada's ("TC" or Applicant) 15-Mile Falls Hydroelectric Project on the Connecticut River in Grafton County, New Hampshire and Caledonia County, Vermont, has earned LIHI's Low Impact Certification. The effective certification date is December 15, 2008. LIHI certification means that the hydropower facility has been found to meet or exceed the Institute's Certification Criteria which address eight key areas: river flows, water quality, fish passage and protection, watershed protection, threatened and endangered species protection, cultural resource protection, recreation, and facilities recommended for removal.
Certification is designed to provide consumers with assurance that a facility has avoided or reduced their environmental impacts pursuant to the Low Impact Hydropower Institute's criteria. The Board's vote to certify the project was unanimous.
Project Summary
• Facility location: Connecticut in, New Hampshire and Vermont.
• Installed capacity: 369 MW
• Average annual generation: 663 gigawatt hours
• Year FERC license issued: April 8, 2002
• Applicant: TransCanada Hydro Northeast Inc.
• Applicant contact: Cleve Kapala
• Date application was posted to website: December 15, 2008
• Date public comment period on application closed: February 15, 2009
• Effective certification date: December 15, 2008
• Certification Expiration: December 15, 2013
Project Description
TransCanada Hydro Northeast, Inc. (Applicant) owns and operates the 15 Mile Falls Hydroelectric Project (FMF or "Project"). The Project is located on the Connecticut River near Littleton, New Hampshire, and Waterford, Vermont. The Project consists of three developments: Moore, Comerford, and McIndoes, with a rated capacity of 291.36 MW The FMF Project area involves about a 26-mile reach of the river,including the three reservoirs and about a 1.5-mile riverine reach between the Comerford and McIndoes reservoirs.
The Moore development, the furthest upstream, is located 283.5 miles from the mouth of the Connecticut River and consists of the following: (1) an 11-mile-long reservoir with a surface area of 3,490 acres and 223,722 acre-feet of gross storage at a normal maximum operating level of 809 feet msl; (2) an earth and concrete gravity dam with an overall length of 2,920 feet and a height of 178 feet; (3) a 373-foot-long concrete spillway with a 15-foot-wide by 20-foot-high sluice gate, four 50-foot bays of 17-foot-high stanchions, and three bays of 36 foot-wide by 30-foot-high tainter gates; (4) four steel penstocks each 296 feet long; and (5) a powerhouse with four Francis type turbine-generator units. The turbines have a combined power rating of 225,600 horsepower (56,400 horsepower each) under a design head of 150 feet and a combined rated discharge of 13,300 cubic feet per second (cfs). Each generator is rated at 35,100 kilowatts (kW), yielding an overall rated capacity for the station of 140,400 kW. Maximum output at full load is 191,960 kW under a net head of 158 feet with a combined turbine discharge of 18,300 cfs.
The Comerford development (see Figure 2) is located 275.2 miles from the mouth of the Connecticut River and consists of the following: (1) an 8-mile-long reservoir with a surface area of 1,093 acres and 32,270 acre-feet of gross storage at a normal maximum operating level of 650 feet msl; (2) an earth and concrete gravity dam with an overall length of 2,253 feet and a height of 170 feet; (3) an 850-foot-long concrete spillway with six 7-foot-wide by 9-foot-high sluice gates, four bays of 8-foot-high flashboards and seven 10-foot-high stanchion bays; (4) four steel penstocks each 150 feet long; and (5) a powerhouse with four Francis type turbine-generator units. The turbines have a combined power rating of 216,800 horsepower (54,200 horsepower each) under a design head of 180 feet and a combined rated discharge of 12,010 cfs. Each generator is rated at 35,100 kW, yielding an overall rated capacity for the station of 140,400 kW. Maximum output at full load is 163,960 kW under a net head of 174 feet with a combined turbine discharge of 13,300 cfs.
The McIndoes development (see Figure 2) is located 268.2 miles from the mouth of the Connecticut River and consists of the following: (1) a 5-mile-long reservoir with a surface area of 543 acres and 5,988 acre-feet of gross storage at a normal maximum operating level of 454 feet msl; (2) a concrete gravity dam with an overall length of 730 feet and a height of 25 feet; (3) a 520-foot-long concrete spillway with a 12-foot-wide by 13-foot-high skimmer gate, three 24-foot-wide by 25-foot-high tainter gates, a 300-foot long spillway flashboard section with 6-foot flashboards, and two 50-foot-wide by 18-foot-high stanchion bays; and (4) a powerhouse with four Kaplan type turbine-generator units. The turbines have a combined power rating of 15,200 horsepower (3,800 horsepower each) under a design head of 29 feet and a combined rated discharge of 5,800 cfs. Each generator is rated at 2,640 kW, yielding an overall rated capacity for the station of 10,560 kW. Maximum output at full load is 13,000 kW under a net head of 26 feet with a combined turbine discharge of 5,800 cfs.
Settlement Agreement
As a result of a cooperative consultation process involving state and federal resource agencies, regional planning agencies, local government associations, and various non-governmental organizations (NGO), the licensee (at that time NEP/USGenNE) and the stakeholders reached a Settlement Agreement on proposed operations and environmental measures. The process of reaching this agreement included examination of the power and non-power tradeoffs and effects of a wide variety of different operational scenarios, based on computer modeling of the Connecticut River from the headwater storage lakes to downstream of the project. Various management scenarios involving combinations of various changes in project operations were evaluated. The operational changes included combinations of the following: various minimum flow levels below the project dams and the Connecticut Lake dams, reduced operating levels on the project impoundments, run-of-river operations, reduced winter drawdown, more stable summer lake levels, stable lake levels in the spring to protect bass spawning, and others.
The various operating scenarios, composed of combinations of these factors, were compared with one another and with current operations in terms of their expected environmental benefits as well as their effects on capacity, energy production, ancillary
services, and other considerations.
This negotiation process, after careful consideration of alternatives, resulted in a balancing of power and non-power interests associated with the FMF Project through the FMF Project Settlement Agreement. In addition, during this negotiation process two separate supplemental agreements were reached: the Connecticut Lakes Supplementary Agreement and the Lake Francis Memorandum of Agreement. These supplemental agreements were negotiated by USGenNE and the stakeholders. These supplemental agreements are considered by the stakeholders to be negotiated as a package with the FMF Project Settlement Agreement. The increased flows released from these lakes under the agreements, would augment downstream flows and improve stream conditions for aquatic life.
The FERC License conditions for this project consist of the operational and environmental measures defined by the FMF Project Settlement Agreement.
For further information about any projects certified as Low Impact, please contact Fred Ayer, LIHI Executive Director at (207) 773-8190, or visit the LIHI website at www.lowimpacthydro.org. LIHI is a nonprofit organization that certifies environmentally low impact hydropower facilities nationwide to help energy consumers, and to support market incentives for reducing the effects of hydropower dams on the nation's rivers and streams.