Deficit thinking is the belief by elites that the public is simply unaware of or unable to understand science and that lack of knowledge prevents the right policy decision. It rarely works as a strategy.

Scholars at Umeå University in Sweden analyzed public opposition to dam removal,  an increasingly common practice as old splash dams and small hydropower dams have become obsolete, and found that disagreements are not based on knowledge deficiency but are instead a case of different understandings and valuation of the environment and the functions it provides. 

Dams provided numerous benefits - flood control, an end to droughts and energy chief among them, but now the argument is that the removal of these dams has ecological benefits. Local residents sometimes contest dam removals.

Dolly Jørgensen, environmental historian at the Department of Ecology and Environmental Science, and ecologist Birgitta Malm-Renöfält,  investigated the types of arguments made for and against dam removal in newspaper articles about dams in the Swedish towns of Alby, Hallstahammar, Orsa, and Tallåsen. 

Dams were once saving the ecology. Now they are harming it. This is the removal of the Kuba dam on the Nätra river in March 2007. Credit: Håkon Söderberg

 "We wanted to understand how the proponents and opponents of dam removal think about the function of two contrasting ecosystems – an existing dam with a pond and a potential running stream without the pond. The local people who fight to have a dam remain in place have often been dismissed as unknowledgeable," says Jørgensen. 

They instead found that those who want to remove the dam place a high value on the return of game fish to the ecosystem, recreational fishing, and vague ideas about restoration in general, while opponents want the dam to remain because of recreational opportunities, the aesthetics of the pond's still water, and the cultural heritage of the pond and the historic dam.

"The public opposition is not based on knowledge deficiency, where more information would lead to better ecological decision-making. The locals simply value different aspects of the environment than scientists or environmentalists that want the dam removed, " says Dolly Jørgensen.

As the number of dam removal projects continues to grow in Sweden and other places in the world, controversies are likely to become more common - a decision to remove or keep the dam will result in one side losing the ecosystem services they value, compromise solutions may be difficult to reach.

 Published in Ecology and Society.