Bounheng Southichak, ELP 2013, Laos Almost every week in a local newspaper, I always come across an article on the hydropower development projects that are now under investigation and/or construction in Laos. It was very interesting to learn that at present, Laos has, in total, 17 dams in operation, and by 2020, the country aims to have at least 100 dams. The government of Laos believes that the development of hydropower can help Laos become the battery of Asia and escape from the status of least-developed country by 2020. This seems to be a very nice plan for driving economic growth as well as meeting the rising demand for energy in Laos and the near by regions such as Thailand, China and Vietnam. However, there are also many questions that pop up into my mind, especially on how much development is too much for Laos, and how Laos can grow sustainably. Throughout my working experience, I have been involved with more than 10 hydropower development projects in Laos, mainly on environmental and social impact assessment and public consultation. When talking about a hydropower development project, there are always two opinions: one from the ecologist’s perspective and one from the engineer’s. The ecologists believe that building dams will have many negative impacts on the environment. For example, the dam will block fish migration routes and also destroy the river’s complex ecosystems that serve as important fish habitats. The dam would also block the flow of sediments and nutrients, affecting agriculture downstream. On the other hand, Engineers believe that they can solve all of the concerns raised by the ecologists. The dam will be built in a more environmentally friendly design that will have less impact on the environment. For instance, the dam will be equipped with bottom outlets for sediment release, the use of fish locks, fish ladders, natural by-pass channel, fish lifts and fish-friendly turbine to allow migration of fish and other aquatic animals around the dam. These techniques seem to be very modern and too expensive, but considering the benefits that will come from selling electricity, these costs could be able to be overcome and funded. In many cases, people tend to believe that the construction of hydropower will reduce significantly the fish population along the river.  However, I found very interesting and conflicting data from many research studies. For example, the Mekong River Commission (2003a) reported that fisheries production in the Mekong basin has been declining considerably over past years, and this happened even before the construction of dams in the upper stream of the Mekong. The cause of fish population decrease is due to the expansion of the population living along the river, overfishing, technology, change of water quality, impact from climate change and so on. On the contrary, the World Fish Center Organization (WFC, 2008) reported that the fisheries production in the Tonle Sap Lake in Cambodia, where it collects water from the Mekong, has increased over the years, rather than declined as many people assume. In fact, the amount of fish per fisher or the amount of fish per unit of effort has declined as competition for the resource has become more intense. Despite the lack of clear evidence of a decline in the overall production of the Mekong fish, I personally believe that the sub-Mekong river basin countries will face a big challenge in dealing with fish production and management due to the fact that there are various factors that influence fish populations in the river. As I am an environmental engineer, I tend to believe that an engineer can develop various types of tools to mitigate the environmental impacts resulting from hydropower. However, I also believe that the ecological system in the river is more complex than we expect. I recall the first principal of economics that I learned in my university: “People face tradeoff,” which implies that when a country wants to develop and lift its people out of poverty, it needs to sacrifice some of its natural resources. The question that I would like to bring in for this post is this: between “Fish” and “Electricity,” which one does the country want to give more weight to and why? What about you? If you have to choose between “fish” and “electricity,” which one will you choose?