Brookfield Power is making several environmental enhancements at its 8.8-MW Varick project on the Oswego River in New York, including minimum flow releases and fish diversion structures. These changes, developed by a diverse group of stakeholders, are improving the watershed and increasing spawning of fish in the area.
By Jon D. Elmer and Steven P. Murphy
Brookfield Power celebrated a significant environmental milestone in late July 2006. The lower Oswego River in Oswego County, New York, was removed from the Environmental Protection Agency’s (EPA) list of Great Lakes Areas of Concern (AOC). These AOCs are the most environmentally degraded areas in the Great Lakes Basin, in both the U.S. and Canada. Only two sites in Canada have been removed from the list since it was developed in the late 1980s. The lower Oswego River is the first AOC in the U.S. to be removed from the list.
This milestone comes in part as a result of several environmental enhancement measures Brookfield Power is implementing at its 8.8-MW Varick hydroelectric facility on the Oswego River. These enhancements are designed to improve the overall health of the watershed and increase spawning of fish species in the lower Oswego River.
Why the Oswego River was an area of concern
The Great Lakes AOCs are severely degraded regions where specific environmental changes have caused or are likely to cause “impairment of beneficial use of the area’s ability to support aquatic life.” In the late 1980s, the U.S. and Canadian governments identified 43 AOCs in the Great Lakes region, 26 in U.S. waters and 17 in Canadian waters. Five of these sites are shared between the U.S. and Canada on connecting river systems. The Great Lakes Water Quality Agreement, amended in 1983, indicates that the two federal governments will cooperate with state and provincial governments to develop and implement remedial action plans for each AOC, with the ultimate goal of removing AOCs from the list.
EPA chose the lower Oswego River as an AOC because upstream pollutants (polychlorinated biphenyls or PCBs, phosphorus, and landfill runoff) had traveled through the river and harbor and affected the ecosystem of Lake Ontario. The pollutants resulted in restriction on fish consumption, degradation of fish and wildlife populations, oxygen loss, undesirable growth of algae, and loss of water clarity.
In 1987, the New York State Department of Environmental Conservation (DEC) established the Oswego River Citizens Advisory Committee, consisting of citizens living in the Oswego River Basin, hydro industry representatives, recreational interests, environmentalists, research scientists, and local government representatives. The goal was to initiate public input into the development of a remedial action plan for the lower Oswego River.
Three years later, the New York State DEC, in cooperation with the advisory committee, developed Stage 1 of a remedial action plan for the Oswego River AOC. Stage 1 identified beneficial use impairments and the causes and sources. The main impairments identified were restrictions on consumption of fish in Lake Ontario (due to PCB and dioxin contamination), loss of fish habitat (as a result of periodically dry areas below Varick Dam), fish population change (loss of walleye eggs as a result of the periodically dry areas), and eutrophic conditions associated with non-AOC sources (municipal sewage discharges, sewer overflows, and street and agricultural runoff).
Stage 2 of the remedial action plan, released in 1991, described actions needed to restore beneficial uses and to eliminate adverse effects to Lake Ontario. The remediation, revitalization, and redevelopment of the lower Oswego River AOC involved extensive pollution reduction activities, watershed best management practices, and sustained cooperation by many entities, such as the public, business, industry, and stage agencies.
Stage 3 of the remedial action plan is the delisting document that resolves each of the beneficial use impairments for the AOC. This document was competed in July 2006.
Removal of the lower Oswego River from the Great Lakes AOC can be attributed in part to Brookfield Power’s efforts to enhance fish habitat between the 8.8-MW Varick development and Lake Ontario. As part of its new FERC operating license, issued in 2004, Brookfield Power has implemented minimum water flow levels, rehabilitated the sluice gates to help regulate flows, and built a low-level diversion structure to ensure sustained water levels and fish habitat. These improvements provide and sustain conditions that support spawning and development of several fish species in this area.
Working toward a new license for the Oswego River Project
The Varick facility is part of the three-powerhouse 18.05-MW Oswego River Project. The licensee for this project is Erie Boulevard Hydropower L.P., a wholly owned subsidiary of Brookfield Power. The original FERC license for the Oswego River Project was granted on May 27, 1968, and expired on December 31, 1993. The project operated under an annual license until the new FERC license was granted on November 30, 2004.
The Oswego River Project includes Varick, as well as 1.25-MW Fulton and 8-MW Minetto, both upstream of Varick. These three facilities produce an average of about 72,500 megawatt-hours of electricity annually. The Varick project features a 730-foot-long and 13-foot-high masonry gravity dam, a 32-acre reservoir, a 1,940-foot-long bypass reach, and four turbine-generating units.
All three hydro developments had operated as store-and-release facilities, using locks and dams owned by the New York State Canal Corporation, a subsidiary of the New York State Thruway Authority. The corporation regulates the Oswego River to control flooding, to provide adequate water levels during navigation season, and to operate the lock and dam system.
However, in its application for a new FERC operating license, Brookfield Power proposed changing project operations to a modified run-of-river mode. This mode of operation would limit reservoir fluctuations and allow for minimum flow releases to support downstream habitat.
Filing the settlement agreement
Brookfield Power filed a settlement agreement for the Oswego River Project with FERC on February 18, 2004. This document included several provisions to protect and enhance fish and wildlife and increase recreation resources in the Oswego River.
Table 1: Bypass Flow Schedule for the Varick Project
The settlement agreement was signed by a diverse group of stakeholders, including the Adirondack Mountain Club, Erie Boulevard Hydropower, Izaak Walton League, New York Rivers United, New York State Conservation Council, New York State Department of Environmental Conservation, and Trout Unlimited.
Changing project operations
FERC agreed to the modified run-of-river operations recommended in the settlement agreement. On November 30, 2004, FERC issued a new license to continue operation and maintenance of the Oswego River Project. As a result, the Varick development, as well as the Fulton and Minetto plants, were converted to run-of-river service within 18 months after the license was issued.
In addition, FERC agreed that the limit of 1 foot for impoundment fluctuations allowed by the proposed run-of-river mode provides nearly the same level of protection to littoral zone habitat as strict run-of-river operations. This limit offers operational flexibility to buffer some of the effects of the seven hydro projects upstream of Varick on the Oswego River. And it provides greater safety for anglers fishing below the Varick development by not exposing them to unexpected spill due to rapid fluctuations, which can occur during project inflows. Under the old operating license, Brookfield fluctuated pond level by 2 to 3 feet.
Providing minimum bypass flows
Within the 18-month period after the FERC license was issued, Brookfield Power agreed to begin releasing minimum bypass flows from the sluice gates at the Varick facility. Table 1 shows the seasonal flows, which range from 200 cubic feet per second (cfs) in the summer to 800 cfs during the two-month walleye spawning season. To provide these flows, Brookfield Power had to rehabilitate the existing gates, at a cost of $105,000. The utility began implementing this bypass flow schedule May 26, 2006.
These bypass flows increase habitat for juvenile, adult, and spawning life stages of riffle-dwelling species, as well as white sucker, spawning walleye, and spawning juvenile smallmouth bass. The bypass flow releases also provide sufficient depth for movement of large salmonids, walleye, and other species that migrate into the bypass reach from Lake Ontario. In addition, these flows provide protection from predation and excessive illegal harvest. Finally, the bypass flows enhance opportunities for fishing, including safe recreational entrance to and exit from the bypass reach.
The settlement agreement included terms allowing the licensee and resource agencies to reevaluate this seasonal flow, as requested by the licensee, a minimum of five years after the license was issued. This will allow the licensee to determine if implementing decreased bypass flows still will meet agency management objectives.
As part of the new operating license, FERC recommended development of a streamflow and water-level monitoring plan. This plan includes gages and equipment to document the utility’s compliance with project impoundment level fluctuations and minimum flow release requirements. Brookfield Power expects to implement this monitoring plan by the summer of 2007.
Constructing a low-level diversion structure
The settlement agreement for the Oswego River Project license included a plan to install a low-level flow diversion structure along part of the western side of the bypass reach near the Varick tailrace. FERC mandated that this structure be installed within 18 months after the new operating license was issued.
The low-level flow diversion structure diverts about 70 percent of the flow from the upper bypassed reach to the lower bypassed reach during the 200-cfs bypass flow period, which lasts from June 1 through September 15. The structure augments the minimum bypass flows by providing increased levels of habitat for invertebrates; spawning for riffle-dwelling species, walleye, white sucker, and smallmouth bass; and juvenile habitat for longnose dace and white sucker. The structure also provides additional flows to the east side of the bypass reach to maintain waterfowl habitat and to improve the aesthetics of the bypass reach.
To design this diversion structure, Brookfield Power’s in-house team relied on flow demonstration studies conducted by Ichthyological Associates in Lansing, N.Y. B-S Industrial of Gouverneur, N.Y., a company that has worked on other Brookfield Power hydro projects in New York State, built the diversion wall. Construction was completed in September 2006, at a cost of $125,000.
Installing fish protection and passage systems
The settlement agreement for the Oswego River Project license also contained two measures intended to improve fish passage. The first was installation of an upstream eel conveyance system at Varick, intended to aid in the upstream migration of American eels so they can use additional habitat. In early 2007, Brookfield Power installed this system, which was built by Technical Erectors in Syracuse, N.Y. This system begins operating in 2007, from June 15 through September 15.
The second measure was installation of 1-inch trashrack overlays at all three hydro projects in the Oswego River Project. Brookfield Power is using a staggered schedule to install these overlays, with all work being completed by 2010. These overlays act as modifications to the existing 4-inch trashracks and will be in place from May 1 through November 30. The new trashrack overlays are intended to physically deter large fish from entering the turbine intake.
Results to date
Brookfield Power’s ongoing commitment to environmental stewardship and the enhancement measures undertaken at the Varick hydroelectric project have led to improved fish habitat on the lower Oswego River. Brookfield Power’s comprehensive settlement agreement for the new Oswego River Project operating license is an excellent example of a diverse group of environmental stewards working together to achieve a sustainable resource for the future.
Mr. Elmer may be reached at Brookfield Power, 800 Starbuck Avenue, Suite 802, Watertown, NY 13801; (1) 315-779-2401; E-mail: jon.elmer@brookfieldpower. com. Mr. Murphy may be reached at Brookfield Power, 225 Greenfield Parkway, Suite 201, Liverpool, NY 13088; (1) 315-413-2788; E-mail: steven.murphy@ brookfieldpower.com.
Jon Elmer, general manager for Brookfield Power’s Lake Ontario operations, is responsible for overall operation of the 8.8-MW Varick facility and negotiating the terms and conditions of the Federal Energy Regulatory Commission (FERC) license. Steve Murphy, a compliance specialist with Brookfield Power, is the project manager responsible for project design, flow studies, implementation, agency consultation, and compliance with the FERC license.