The Gilgel Gibe III hydroelectric dam under construction in Ethiopia is no small piece of infrastructure. It holds the potential to fundamentally alter flow patterns in the Omo River watershed and will cost about $2 billion to build. It will indeed have impacts -- both positive and negative -- on the environment and people living in the watershed.

Yet, do these facts make the project inherently bad? Does the fact that the investment is big and costly doom it to failure? In her May 14 Times Op-Ed article, Lori Pottinger uses such thinking to argue that the African Development Bank and U.S. government should not finance the dam's construction and instead look for alternatives to address Ethiopia's water and environmental needs.

While the social and environmental costs of building this project are significant, Ethiopia would benefit from this dam. According to numerous analyses that weigh both the costs and benefits of Gibe III, Ethiopia's electricity generation capacity will more than double when the dam is up and running, allowing economically debilitating power cuts to be reduced and electricity to be extended to at least some of the more than 70% of the population without access. Power exports will bring revenue into the country, helping to lift annual per capita income above its current level of about $150. The project's water storage capacity will reduce the impacts of droughts. Finally, the impacts of floods will be reduced by "taming" the Omo, to use Pottinger's words. In 2006, a devastating flood claimed the lives of at least 360 people and thousands of livestock and imperiled the livelihoods of poor Ethiopians in the lower Omo River basin -- downstream from the proposed dam.

Granted, a project of this size will impose costs that are more than just financial. To address this, the Ethiopian government commissioned environmental and social-impact assessments; it subsequently endorsed and adopted several mitigation plans. Included in these plans (all of which can be found at this Web site) is one even for archaeological preservation. These plans may not be perfect or followed to the letter, so valid criticism may be directed toward the way in which environmental and social costs are mitigated.

But lobbying to block Gibe III's construction simply because of the project's size and social and environmental costs, however, is dangerous and irresponsible. We should not glamorize the rural lives of those dependent on the river, most of whom remain poor, deprived of basic needs and vulnerable to the droughts and floods that are likely to become more frequent as a result of climate change. This dam would tap a renewable resource (water) and, by diversifying sources of electricity, help to drought-proof Ethiopia's energy sector. The country has the potential to generate 30,000 megawatts of hydropower electricity; Gibe III realizes just 1,870 megawatts, adding to Ethiopia's current meager 790.

Criticism is likely warranted in the case of Gibe III, as large dam investments are seldom realized without leaving at least some people disaffected and under-compensated. But dogma-based criticism, based on institutional mandates or personal philosophies, often distracts attention from the real issues and discussion that need to take place. Only serious discussion that looks at the complete picture of costs and benefits fosters the socially conscious and environmentally sustainable development solutions so desperately needed in the world's poorest regions.

Seleshi Bekele, a senior researcher with the International Water Management Institute, is head of the group's East Africa and Nile Basin office based in Ethiopia. Jonathan Lautze is a post-doctoral fellow with the institute.