Professor explores science, politics of dams

Love ’em or hate ’em, there is one indisputable fact about dams in America: Thousands of them are aging, obsolete and dangerous, and await either a repair bill or a wrecking ball.

There is little detailed scientific information about dam removal and all of the cascading effects it creates on water quality, landscapes, fish and wildlife. The Baraboo River could serve as a national model for biologists of how rivers respond to this great unleashing of their currents.

In towns across the country, the emotional question of whether a dam is a community asset or an environmental scourge will be frequently debated in coming years. But a university ecologist hopes to ground the question on a sound scientific footing.

Emily Stanley, an assistant professor of zoology and scientist with the Center for Limnology, plans to use a dam removal project on Wisconsin’s Baraboo River as a unique opportunity to gather important ecological data before and after the breach.

Surprisingly, Stanley says, there is little detailed scientific information about dam removal and all of the cascading effects it creates on water quality, landscapes, fish and wildlife. The Baraboo River could serve as a national model for biologists of how rivers respond to this great unleashing of their currents.

An aging dam on the upper Baraboo River in LaValle is scheduled for removal in 2001. The Sand County Foundation, a regional environmental group, purchased an option on the dam and is leading removal plans, along with the Wisconsin Department of Natural Resources.

The Baraboo River will be a particularly compelling case study, Stanley says, because the river faces three dam removals. After LaValle, another two dams are expected to be removed in the city of Baraboo. In addition, two dams were removed earlier, one in the 1970s and one just two years ago.

“We can look at changes with respect to the entire river basin,” she says.

Among the questions: Will native plants, trees and wetlands return to the land that was underwater? Will the flushing of sediment reintroduce some agricultural chemicals that compromise water quality? Will the aquatic food chain look completely different before and after the dam? Will river-dependent species of fish make a comeback, and what species will they replace?

“One thing people would love to see in the Baraboo is sturgeon running again,” Stanley says. “The area in downtown Baraboo was an historically important sturgeon breeding area.”

But some potential losses would need to be prevented by the project. For example, the mill pond currently attracts great bird populations, including a pair of nesting bald eagles, she says.

On a national scale, dam removal is being driven by economic and legal reasons, Stanley says. Most dams were built between 1860 and the 1920s and have a life expectancy of about 100 years. As inspections turn up safety problems, some towns are faced with six-figure price tags for repairs. The DNR says 30 dams may be razed in the next five years alone.

Economics aside, many environmental groups are taking this opportunity to push dam removal as a national priority.

“There is a campaign to return rivers to what they ought to be, which is a free-flowing water course, to get native fish back in, to circulate the water and flush out the sediment,” she says. “This is what rivers do, they flow through channels and don’t get stuck behind dams.”

Yet many residents use and appreciate the impoundments created by dams. Removing them may leave homes along the quiet, glassy waters high and dry, and some recreational opportunities may be lost.

Stanley says she believes baseline scientific information will be useful to all the stakeholders in these debates. And it could give land managers “a potentially powerful tool for river restoration.”