Interview: New Decision-Making Tool to Assess Dam Impacts

Katy Yan
Desiree Tullos explaining the IDAM at the Woodrow Wilson Center
Desiree Tullos explaining the IDAM at the Woodrow Wilson Center

Catching the tail end of the DC heat wave at the end of July, I attended two events hosted by the China Environment Forum at the Woodrow Wilson Center. Both events included a presentation and demonstration of the IDAM, or the Integrative Dam Assessment Modeling tool, and its application in southwest China.

Leading the IDAM project is an interdisciplinary team of scientists and anthropologists from Oregon State University and the Hobart and William Smith College, who developed the IDAM to support more informed and transparent decision-making processes related to dam development, with the goal of "reducing the uncertainty and risks associated with constructing (and removing) dams." I spoke with one of the leads on this project, Desiree Tullos, to hear what she had to say about dams and decision-making in China – home to half the world's large dams and the site of major dam construction efforts in the coming decades.

How does the IDAM tool work?

DT: The IDAM tool is designed to integrate biophysical, socioeconomic, and geopolitical perspectives into a single cost/benefit analysis of dam construction. Each of 21 different impacts of dam construction is evaluated both objectively and subjectively by a team of decision-makers. By providing a visual representation of the various costs and benefits associated with two or more dams, the IDAM tool allows decision-makers to evaluate alternatives and to articulate priorities associated with a dam project, making the decision process about dams more informed and more transparent.

What was your inspiration for the IDAM tool and where have you used it? 

DT: We were originally inspired by the belief that there is so much to gain by investigating water resources solutions as interdisciplinary teams. But it was the recommendation by the World Commission on Dams, which called for a comprehensive Options Assessment in decision-making about dams, that led us to begin thinking about how such a framework might be structured, and then to seek support from the National Science Foundation to begin developing, evaluating, revising, and applying it. 

Nu and Lancang basins in southwest China
Nu and Lancang basins in southwest China

We focused our application on hydropower development in the Yunnan Province of China [editor's note: see Nu and Lancang Rivers] to study specific research interests for our team, including how impact distributions vary across disciplines, space, and stakeholder groups in China. We analyzed the interdisciplinary impacts of centralized and decentralized hydropower development and regional planning (e.g. transboundary collaboration) policies, and characterized how salience influences decision-making about dams.

While there certainly are limitations around particular components of the framework, the tool is intended to facilitate discussion among various stakeholders and, based on several meetings we've coordinated under this project, I believe it has been effective in that regard.

How would you define sustainable hydro?

DT: Sustainable hydropower meets a demonstrated energy need (rather than developing hydropower because it is available), is part of a larger energy and environmental planning process, which is both transparent and equitable, and does not result in permanent losses to irreplaceable elements of the system. Environmental, economic, and social benefits need to be demonstrated and costs should be minimal or mitigated.

There is already a substantial body of knowledge about design and operational practices that minimize impacts of hydropower on people and the environment, and it is expanding every day through research that links fluid mechanics with ecology and engineering. The critical issue is adopting those practices, which often incur additional costs and construction delays themselves. However, as we look to the future, whether we're talking about species extinction, loss of cultural heritage, or even severe reductions in reservoir capacity due to sedimentation, it is hard to argue that these practices are not worth the time and money. I believe it is the impacts to the irreplaceable elements of the system and those that lead to the permanent loss of function (be it hydropower generation, water quality, food web dynamics) that make any project fall into the class of "unsustainable."

How is this different from other assessment tools?

DT: A key element is that the framework makes individual salience, or how we value or care about a particular impact, explicit and transparent. This element alone has facilitated important discussions and highlighted fundamental differences between stakeholders. The salience element is what makes this different from other decision-analysis tools, but it is really intended to be complementary to other decision-analysis approaches.

How do you envision the IDAM being applied and by whom?

DT: We originally developed this tool with our plans to apply it on hydropower development in rural China in mind, but deliberately structured the tool to be flexible so that it could be used in any geographical setting and for multi-purpose (e.g. flood control, irrigation and municipal supply) projects. We are currently wrapping up edits to the IDAM software and documentation. In the future, we may use elements of IDAM in analyzing scenarios considered under the renegotiation of the Columbia River Treaty.

More information: 

"Dams and Sustainability in China" live webcast at the China Environment Forum: