Resource information
This paper provides a simple, yet
robust, methodology for comparing proposed hydroelectric
project sites in terms of their expected negative
environmental impacts, and relating these to power
generation benefits. The paper also summarizes the
environmental mitigation options for large dams. If properly
implemented, these mitigation measures can effectively
prevent, minimize, or compensate for many (though not all)
of a hydroelectric project's negative impacts.
Nonetheless, the most effective environmental mitigation
measure is good site selection, to ensure that the proposed
dam will cause relatively little damage in the first place.
The paper presents quantitative indicators (using data that
are relatively easy to obtain) for rating and ranking
proposed new hydroelectric projects in terms of their likely
adverse environmental impacts. Projects with a small
reservoir surface area (relative to power generation) tend
to be most desirable from both an environmental and social
standpoint, in part because they minimize natural habitat
losses as well as resettlement needs. In general, the most
environmentally benign hydroelectric dam sites are on upper
tributaries, while the most problematic ones are on the
large main stems of rivers.
