At its November Governing Board meeting, the decision to certify the three projects was unanimous, and included the addition of non-standard conditions to the Farmers Irrigation District and Ashuelot projects.
The Winooski project is located in the cities of Burlington and Winooski in Chittenden County, Vermont. The 7.4MW facility, which was constructed over 1991-93, has also been known as the ‘Chase Mill hydroelectric project’. The run-of-river facility is located at lower Winooski Falls on the Winooski River, and has a refurbished spillway with crest gates abutting a historic timber crib dam that dates from 1876. The dam is on the National Register of Historic Places as part of the Winooski Falls Mill District. The applicant also constructed fish passage facilities and a riverside park and trail as part of the project.
During the re-certification review, LIHI was impressed with the fact that nearly every one of the federal, state, and local agency staff contacted in the course of this review commented that the applicant had demonstrated extraordinarily good corporate citizenship in carrying out and often exceeding the requirements associated with the project’s construction and operation.
The Farmers Irrigation District hydroelectric projects are located on tributaries and the main stem of the Hood River near the Columbia River Gorge in Oregon. The projects, including penstocks and powerhouses, were constructed in the mid-1980s to produce renewable energy for the Bonneville Power grid and provide revenue to the District to be used for water conservation, stream restoration, and fish screen projects. The project consists of two powerhouses. The upper powerhouse contains a 1.8MW generator with a horizontal axis Pelton turbine; the lower powerhouse contains two generators – 1MW and 2MW – driven by horizontal axis Francis turbines. Each plant has its own switchgear, and electricity flows from both plants to a single substation, which is connected directly to the Bonneville grid.
The projects are run-of-river, and no dams are associated with the project’s six water diversion systems. Water flows to the upper powerhouse forebay through the 16km long Lowline canal and pipe system; water to the lower plant forebay flows through the 8km long Farmers canal and pipe system. The project has no reservoir storage other than the forebay, canal, and pipe systems. A 8km long, 36-inch diameter penstock provides water to the upper turbine, and a 3.2km long, 48-inch diameter penstock conveys water to the lower turbines. Water from the upper plant also flows through the lower plant. Farmers Irrigation District owns the project facilities and holds easements for the canals, pipes, forebays, penstocks, and transmission lines.
The District diverts its project water through self-cleaning, horizontal fish screens, a technology developed by the District that allows fish to pass through the diversion systems without harm. The District maintains year-round minimum flows in Green Point Creek, a premier anadromous fish-bearing stream that is one of the sources of water for the upper plant. The upper plant is operated at reduced capacity if Green Point Creek flow drops below the minimum, and the plant typically does not run at all during the summer months. In the 1990s, the Hood River was listed for Threatened salmon and steelhead, and the Hood River was also placed on the 303d list for water temperature. In the response to these listings, in a concerted effort to ensure that the District’s power plants are low impact, the District is presently working with the Oregon Department of Fish and Wildlife, Oregon Department of Environmental Quality, and the Confederated Tribes of Warm Springs to alter plant operation to enhance Hood River mainstem in-stream flow during the summer months and ensure that the District’s project does not increase water temperature.
The LIHI Governing Board’s decision included non-standard conditions requiring the FID to monitor and report the success of measures aimed at mitigating/enhancing water temperatures in the Hood River and to formalize recreational access to a project reservoir.
The Lower Robertson and Ashuelot Hydroelectric pojects are located on the Ashuelot River in Winchester, New Hampshire. Both projects are small, low head, run-of-river hydro plants built in the mid 1980's at existing paper company dams. The Lower Robertson project consists of an 5.5m high dam with a spillway crest elevation 384.6 msl, 0.5m high flashboards, impoundment with a surface area of 8.6 acres; an intake structure and powerhouse at the north end of the dam with three turbine generator units with a total installed capacity of 840kW, and a short tailrace.
The Ashuelot project includes a 5.5m high timber cribbed dam with a spillway crest elevation of 335.4 msl, 1m high flashboards, a small impoundment, intake structure and powerhouse at the south end of the dam with three turbine generator units with a total installed capacity of 870kW, and a 30m long tailrace.
The LIHI Governing Board’s decision for this project includes non-standard conditions requiring that the Applicant provide documentation that the Projects meet New Hampshire surface water quality standards by the end of 2010 and that the Applicant finalizes and formalizes a recreational plan accepted by FERC by the end of February 2010.
