Western Wisconsin Hydro Plants

Xcel Energy operates 19 hydroelectric plants in Wisconsin, with a total generating capacity of about 260 megawatts (MW). Five of those plants are located on three rivers in western Wisconsin: the St. Croix, the Apple and the Red Cedar.

Hydro Description: Hydroelectric generation begins with a dam that holds back a river and diverts flow through a powerhouse. Falling water that flows through propeller-like turbines causes them to rotate. The rotation of these turbines spins generators to produce electricity. The amount of electricity generated from each unit is determined largely by volume of water flow and "head," or the height from the water surface at the dam reservoir to the water surface downstream.

Hydro Highlights: As a source of electricity, hydropower is advantageous in that the fuel costs nothing. In addition, hydro facilities have low operating and maintenance costs, and their useful lifetime is well over 50 years.

From an environmental perspective, hydro is a clean, renewable fuel, and Xcel Energy manages its dam operations to protect the aquatic environment and improve recreational opportunities

Plant Descriptions

The St. Croix River
St. Croix Hydro (25 MW)
The St. Croix River is a federally designated natural and scenic river way, and St. Croix Hydro is the only existing dam on the river. Completed in 1907, the plant was built to provide electricity across the river to Minneapolis-St. Paul. A feature that distinguishes the St. Croix Falls plant from other Xcel Energy hydros is its S-shaped spillway. The spillway had to be constructed as a curve to increase its crest area, because the river at the site forms a gorge through which passes a large volume of water.

The Apple River
The Apple River is a relatively small stream that meanders through 55 miles of pastoral countryside to the St. Croix River near Somerset, Wis. During the summer months, visitors from the Twin Cities and western Wisconsin crowd nearby campsites and businesses, renting innertubes for leisurely float trips.

Riverdale Hydro (0.6 MW)
The second smallest hydro plant in the Wisconsin system, Riverdale's operating regimen has remained the same for many years: maintain adequate stream flow to accommodate the pleasure trips that begin just downstream from the plant. The plant is remotely controlled. The site includes a small picturesque powerhouse with two generating units and a narrow overflow spillway.

Apple River Hydro (2.9 MW)
Located 7 miles downstream from Riverdale and 2 miles before the Apple River's confluence with the St. Croix, the Apple River facility is a diversion project. The dam is located around a bend about 2,000 feet upstream from the powerhouse, with a flume that diverts water at the dam to the powerhouse. Bypassing the bend in the river increases the available head to 82 feet. Much of the original equipment from the 1907-vintage plant remained in operation until 1988, when a major renovation was begun. The original generators, which were among the first alternating current machines manufactured, were removed at that time.

Red Cedar River
With its headwaters in Barron and Washburn counties the Red Cedar River flows almost 100 miles south to its union with the Chippewa River. During the last half of the 19th century, the river was used as a logging run by a Menomonie, Wis.-based firm that was the largest lumber producer in the United States. Today the river is noted for its scenic and recreational value.

Cedar Falls Hydro (6.8 MW)
Cedar Falls is a modified run-of-the-river operation. The original Cedar Falls timber dam was replaced with a concrete structure in 1910, with new generators added in 1912 and 1915. Since then, the plant has operated largely unchanged — a testimony to the durability of hydro plants.

Menomonie Hydro (5.1 MW)
Menomonie Hydro is operated by remote control from the Wissota control center. The original Menomonie dam, built in 1848, was severely damaged by floods in 1934 and 1950. The original facility was replaced with a new dam and powerhouse in 1950, and the impoundment was raised 10 feet at the time. The dam creates 1,800-acre Lake Menomin, which serves as an excellent urban recreational resource.

Contact Information:

• Plant Information and Tour Requests — 1-800-895-4999
• Media Inquiries — 715-839-2565