Activity A: Three Gorges Dam Classroom Debate
Countries construct dams and their reservoirs formany reasons, including flood control and economic prosperity. With the benefits, however, come risks and consequences. Through this debate, we will examine and assess a wide range of the environmental impacts of dams on river systems.
The Hoover Dam, constructed in the 1930s, started the trend for mega- or large dams (at least 100m high) that continues today. The Three Gorges Dam on China’s Yangtze River crowns the large-dam movement, at least for now. In a country that has embraced the mega-project, the Three Gorges Dam is the largest man-made structure in the world. Like most mega-projects, the dam serves many purposes that span the political, economic, and social. Besides flood control, navigation, and hydroelectric power generation, the dam has political meaning. By building the world’s largest dam, China has made a statement to the world about its engineering abilities and its governmental power. Nonetheless, large dams are controversial because of their impacts on local inhabitants and the local environment. Debates continue among engineers, scientists, and politicians about the role of large dams, and if they are even necessary or if a series of smaller dams accomplish the same goals.
Come to class having read and taken notes on the preparatory material on the pros and cons of dams, especially large-dams. Pay particular attention in the readings to the various socio-economic, political, archeological, and environmental consequences of the 3 Gorges Dam. Class time will take place in a debate format. In class you be assigned to either support or oppose the construction of mega-dams.
Preparatory Questions
  1. Why are dams constructed?
  2. At what size do we consider a dam large? Where are the largest dams and reservoirs?
  3. What are the environmental requirements (e.g. geology, location) for building a dam?
  4. What is the history of the construction of ‘big dams’ (those over 100 m high)?
  5. What are the environmental requirements (e.g. geology, location) for building a dam?
  6. Referring to water levels in the reservoir and water discharge releases, explain how dams operate.
  7. What are the (upstream and downstream) effects of dam construction on:
  1. the hydrology of the river?
  2. the geomorphology and sedimentology of the river?
  3. the water quality and ecology of the river?
  1. Once constructed, what are the (upstream and downstream) effects of a dam operation on:
  1. the hydrology of the river?
  2. the geomorphology and sedimentology of the river?
  3. the water quality and ecology of the river?
  1. Do all dams prevent floods?
  2. What are the socio-economic impacts of dams, particularly in developing countries? Who are the ‘winners’ and ‘losers’ and why?
  3. What are the recent trends in dam construction?
Format
  1. Groups will be given time to organize their arguments and co-ordinate their response. [15-20 minutes]
  2. The group ‘For’ the issue will be asked to put forward their arguments. Each member of the group is encouraged to contribute something to the presentation. [10 minutes]
  3. The group ‘Against’ the issue then puts forward their arguments. [10 minutes]
All points should be addressed to the Chair and not to the other delegates.
  1. Cross-questioning via the Chair is then allowed (and encouraged). [15+ mins]
All viewpoints must be given to the Chairperson, not directly to another debater. The Chair will not allow delegates to argue with one another.
  1. The debate will be summed up by the Chair. [3-4 mins]