Hydro Review

Summersville: Building a New Hydro Plant at an Existing Dam

The 80-MW Summersville project in West Virginia – completed at a U.S. Army Corps of Engineers’ dam – provides 200 gigawatt-hours of clean electricity each year, enhanced recreational opportunities for river users, and revenue for the city and the federal government. Summersville illustrates the promise and challenges of building new hydro facilities at existing dams.

By Beth E. Harris and Donald P. Jarrett

The Summersville Dam, near Summersville, W.Va., is the second highest dam east of the Mississippi River. Authorization for the dam was provided in the Flood Control Act of 1938; the U.S. Army Corps of Engineers completed the dam in May 1966. Behind the 390-foot-high structure, a 2,790-acre reservoir stores water for flood control, recreation, and flow augmentation.

When the 80-MW Summersville project began commercial operation on July 30, 2001, it represented the culmination of a lengthy development process involving the U.S. government, the city of Summersville, and several private companies. Completion of the project also was a tribute to the tenacity and perseverance of the original developer, Noah Corporation, in prevailing through a development process that took more than 20 years.

The Summersville project (sometimes referred to as the Gauley River project) also serves as an example of installing low-cost hydropower at existing dams in the U.S. Potential to capture unused energy at existing dams has long been recognized; the National Hydropower Association estimates that more than 20,000 MW of new hydropower could be installed in the U.S. without building a single new dam.

Summersville Lake Project: serving multiple needs

The site of the Summersville hydro plant is the Corps’ Summersville Lake Project on the Gauley River near the city of Summersville. The lake and dam, which control a drainage area of 803 square miles, were built under the supervision of the Corps between 1960 and 1966 at a cost of $48 million. The primary purpose of the original project was protection from flooding of the Gauley and Kanawha rivers. According to Corps estimates, by the end of 1996, the Summersville Lake Project had paid for itself many times over by preventing flood damage estimated at almost $345 million.

Summersville Dam and Lake are operated as “run-of-the-river” with designated lake drawdown and refill periods. During the summer, the lake is raised to Elevation 1,652 feet above sea level, providing 2,790 surface acres of water for recreation. During late fall and winter, the Corps lowers the lake to Elevation 1,575 to provide maximum storage of floodwaters. Water was released from the lake through a 1,555-foot-long, 29-foot-diameter tunnel controlled at the lower end through Corps release facilities and, now, through the Summerville hydroelectric project, unless flows are too low.

The Summersville Dam is at the upstream end of the Gauley River National Recreation Area. The dam is also important for its effect on whitewater flows in the downstream reach of the Gauley River. The Gauley River National Recreation Area was created in 1978 and is administered by the National Park Service. Twenty-five miles of free-flowing Gauley River and the 6 miles of the tributary Meadow River pass through scenic gorges and valleys containing a wide variety of natural and cultural features. The Gauley River contains several Class V+ rapids, making it one of the most adventurous whitewater boating rivers in the eastern U.S.

Reviewing the long history of hydro project development

Jim Price of Noah Corporation formulated the initial vision for hydro development at Summersville Lake. Noah Corporation is a small company that has been involved in hydropower development activities in the West Virginia, Kentucky, and Ohio area since the late 1970s. To implement his vision, in 1978 Price approached the city of Summersville with a proposal to co-develop the project, with the city to be the Federal Energy Regulatory Commission (FERC) licensee and Noah as the developer bearing most of the development risk. Noah (through a project company) and the city finalized a development agreement in 1980, FERC issued a preliminary permit for the project in 1981, and the city submitted a license application to FERC in 1983.

At that time, however, the Gauley River had been designated “wild and scenic,” and FERC dismissed the license application on that basis. Two years later, in 1985, by recommendation of the President of the U.S., the Summersville Lake site was exempted from the wild and scenic designation, with the proviso that no development would take place until 1988.


Development of an 80-MW hydro plant at the U.S. Army Corps of Engineers’ Summersville Dam in West Virginia resulted in additional renewable energy, enhanced recreation, improved water quality, and a source of revenue for the nearby city of Summersville.
Click here to enlarge image

When the development moratorium was lifted, the city filed for another preliminary permit, as did a competitor, also seeking the right to develop the site. FERC accepted the city’s new license application in 1989, and issued a 50-year license (FERC No. 10813) in 1992. Prior to license issuance, the city of Summersville signed memoranda of understanding with the West Virginia Department of Natural Resources and the National Park Service for specific mitigation and enhancement measures to be put in place as part of project development.

During this time, the competing applicant claimed that by co-developing the project with a private company, the city was abusing the “municipal preference” provision of the Federal Power Act. This provision requires FERC to choose a public power applicant over a non-public power competitor in cases where competing applications have substantially equal merit. However, for the Summersville project, FERC denied the competitor’s claim at the time it issued the license to the city.

Even with the license in hand, the city and Noah still had considerable work to complete before construction could begin. In 1993, the Corps signed a memorandum of understanding with the city, Noah, and development entity Gauley River Power Partners (GRPP) to allow construction of the hydro plant at the Summersville Lake Dam.

In 1995 Catamount Energy, the independent power subsidiary of Central Vermont Public Service Company, assumed ownership of GRPP as the principal equity provider. New York Life Insurance Company provided a commitment for debt financing.

In 1996, the project obtained a power purchase agreement with Appalachian Power Company (APC), a subsidiary of American Electric Power, to sell the power over 30 years. By purchasing the output from the Summersville project, APC offsets purchases from coal-fired power plants, thus reducing pollution.

The final pre-construction step occurred in 1998, when the project obtained both equity and debt financing. The debt financing was secured through New York Life Insurance and has a 26-year term.

In 1998, 20 years after Jim Price first started to work on the project, Black and Veatch of Kansas City, Mo., was engaged by GRPP to provide engineering, procurement, and construction (EPC) services in the development of Summersville. IMPSA International was selected to supply the turbines, generators, and auxiliary equipment.

The project’s location at the base of the existing Summersville Lake Dam should have made construction planning and execution relatively simple and straightforward. Unfortunately, the project construction was contentious at times and eventually involved a settlement agreement between GRPP, Black & Veatch, and IMPSA. Besides dealing with construction claims with Black & Veatch, GRPP’s owner Catamount had to deal with a difficult land acquisition for the project’s transmission line. A number of landowners along the 10-mile-long transmission line had to be threatened with condemnation before land rights agreements could be secured.

Commercial operation began July 30, 2001. Total cost of the project was approximately $60 million.

In 2002, Catamount Energy decided to sell its interests in the project due to a change in its strategic focus. CHI Energy, Inc. of Stamford, Connecticut (now known as Enel North America, Inc.) acquired GRPP from Catamount in December 2002, and currently owns and operates the project on behalf of the city of Summersville.

A state-of-the-art facility

The Summersville project represents a state-of-the-art facility in terms of its technology and environmental enhancement. The powerhouse features two vertical Francis turbines, each directly coupled to synchronous generators. Each 40-MW turbine can operate over a range of head from 200 to 280 feet and can discharge from 800 to 4,800 cubic feet per second (cfs). Project power is delivered over a 10-mile-long transmission line operating at 69 kilovolts (kV) to APC. The transmission line was constructed as part of the project facilities.

The control system allows for remote and unmanned operations. A programmable logic controller (PLC) provides start, stop, and operational sequencing. Since the operation of the facility is based on flow releases dictated by the Corps, flow can be changed either on site or remotely. In an emergency, the Corps can shut down the project and release flows from existing valves.

Environmental and recreational enhancements

Installation of hydropower at Summersville Dam resulted in virtually no environmental effects. The hydroelectric project preserves the original operation of the federal Summersville Lake Project, releasing water (and consequently generating electricity) in accordance with the mandates of the Corps.


Partnering with a private development company enabled the city of Summersville,West Virginia, to construct the Summersville hydro project without incurring financial risk.
Click here to enlarge image

As a part of the development of the hydroelectric project, GRPP made and paid for significant recreational enhancements. These enhancements were not required as mitigation; instead, the developer included them to add non-power benefits at the project. Without the new hydroelectric project, it is doubtful that the Corps, the National Park Service, or the West Virginia Department of Natural Resources would have had funding to implement any of these improvements.

Recreational enhancements include:

– Installation of new whitewater raft launch facilities below the powerhouse. This new facility replaces an old launch site and includes a new paved access road and parking lot;

– Building of new restroom facilities adjacent to the new whitewater raft launch facilities;

– Development of a new recreational access site on the shore of Summersville Lake. This new facility includes a new access road to the waterfront for fishermen, swimmers, and others. Additionally, the developer provided improved fishing access at the base of the dam.

– Provision of funding for management of fish and wildlife resources in the project vicinity. Annual payments ($32,000 until year 16; $70,000 after year 16 plus a one-time payment of $250,000) are made to the West Virginia Department of Natural Resources.

Fishing in the reservoir and downstream of the project is popular in the area. The recreational enhancements made as part of the development of the hydro project significantly enhanced fishing opportunities.

A major issue during the development of the project was to continue the ability to provide releases not only for flood control but also for recreation. Whitewater rafting below the dam is an important recreational activity and a source of tourism that greatly benefits the local area. The Gauley River below the dam is a renowned whitewater recreation river. Prior to construction of the hydro plant, each year during the annual Gauley River Days, the Corps released enough flow from Summersville Lake to create Class V+ rapids downstream of the dam. Enel continues this practice by releasing water for whitewater rafting.

Project operations

The project is operated and maintained by a two-person operations staff. These on-site staff take care of routine maintenance and operations, including coordination of operations with the Corps and Appalachian Power Company. Major maintenance support, regulatory compliance, and overall project administration is handled by Enel North America’s staff at its operations headquarters in Andover, Massachusetts.

An important aspect of daily operation is to provide a release of water to the Gauley River downstream of the dam, based on the requirements of the Corps in accordance with a daily release schedule. Because the releases are critical, the hydro project design includes redundancy in the way in which water releases can be made. GRPP relocated an existing 11-foot-diameter Howell Bunger valve, originally installed by the Corps at the dam’s outlet structure for controlling water releases, to a position adjacent to the powerhouse. A new penstock extends from the original valve location to the powerhouse and, through a bifurcation, can conduct water either to the powerhouse or to the valve in its new location.

During normal operation, the project’s automatic control system operates the turbines to maintain the Corps’ mandated prescheduled releases. If for any reason the turbines cannot make the scheduled releases, then releases are made through the Corps’ Howell Bunger valve(s). Since the hydro project began operation, this system has worked well: flow releases have not varied from pre-hydro operations, and all releases continue to be under Corps control.

Environmental benefits

Relocation of the Howell Bunger valve also provides an environmental benefit. Hydro project developers installed recording equipment to continuously monitor dissolved oxygen (DO) levels downstream of the project. If DO drops below 7 milligrams per liter, the project operates a blower in the powerhouse to increase aeration of the water. If this does not increase the DO to the required limit, the project is shut down and flows are released through the Corps valves, which aerates the water.

For two years prior to the start of construction of the hydro project, developers monitored DO levels. The levels were acceptable most of the time; however, there was no means of increasing levels nor provision by the Corps to increase levels. Consequently, the GRPP decided to install a system to monitor the levels. When DO is too low, a course of action is taken, resulting in improved water quality. This system protects downstream aquatic resources and assures that there is no degradation of water quality due to project operations. To date, low DO incidents requiring the shutdown of the project have been rare, occurring only once or twice per year during dry seasons.

The project is certified by the Low Impact Hydro Institute (LIHI) as “low impact.”

Economic benefits for the city

The development of the project provides an additional benefit to the city of Summersville. The city would not have had the resources to develop this project nor was in a position to accept the development risks. By entering into a public/private relationship, the city was able to develop the hydro project (a source of revenue) without incurring risk.

Under the public/private partnership agreement, the city receives a base royalty – a percentage of power sales revenues, as well as an incentive payment when generation exceeds certain levels. GRPP (owned by Enel), as the private partner, operates the project for the first 30 years at no cost to the city. After 30 years, Enel returns the project to the city. At that point, the city will own the project with no debt.

Lessons learned

The FERC licensing process, extensive negotiations with the Corps, National Park Service, and the West Virginia Department of Natural Resources, and the construction process took (too) many years. The length of the process points to the need for continued regulatory adjustments to accelerate the development of new hydro at existing dams.

The actual design and construction of the project took a rather convoluted path. Catamount initially intended to construct the project under an engineering-procurement-construction (EPC) contract arrangement. Generally, developers prefer the EPC arrangement in that it limits developer risk during the design and construction phase. In the usual EPC arrangement the contractor procures all equipment, minimizing interface issues and potential for change orders. At some point in the process, Catamount decided, owing to sales tax issues, to split out the turbine-generator equipment supply.

In retrospect, Catamount wishes it had not split out the procurement of the turbine generator equipment from the Black & Veatch EPC contract. Having owner-furnished equipment made coordination more difficult and provided opportunities for claims during the construction.

There were a number of disagreements between Black & Veatch and the Corps concerning design and construction issues. To some extent, these disputes should be expected because it is natural for the EPC contractor to disagree with decisions that increase construction cost. Catamount recommends that a developer stay closely involved in these issues to help quickly resolve disagreements.

Worth the wait

The Summersville hydroelectric project illustrates the length of time and perseverance sometimes required to complete a new hydro project. In this case, the licensing process alone required nearly 12 years to complete.

In the end, though, the completed project serves as an example of how adding a hydropower component to an existing dam can provide additional renewable energy, enhance recreation, benefit the environment, and provide a source of revenue for local, state, and/or federal government entities.

Ms. Harris may be contacted at Enel North America, 11 Anderson Street, Piedmont, SC 29673; (1) 864 846-0042; E-mail: beth.harris@northamerica.enel. it. Mr. Jarrett may be contacted at EES Consulting, 570 Kirkland Way, Kirkland, WA 98033; (1) 425 889-2700; E-mail: jarrett@eesconsulting.com.

Acknowledgment

The authors express appreciation to Kenneth Halstead and Steven Wright of the U.S. Army Corps of Engineers, Jim Price of the Noah Corporation, Bruce Peacock with Catamount Energy, and Wayne VanDenBurg and Chris Hocker, both previously with CHI Energy, for their assistance with this article.

Beth Harris is the project engineer/ manager, regulatory, for Consolidated Hydro Southeast, Inc. a subsidiary of Enel North America, Inc. Don Jarrett is a senior engineer and technical manager at EES Consulting. Previously, he was vice president of operations for CHI Energy, Inc., now known as Enel North America.

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