The water strategies of the 20th century helped to supply drinking water, food,
flood control and electricity to a large portion of the human population. These
strategies largely focused on engineering projects to store, extract and control water
for human benefit. Indeed, it is hard to fathom today's world of 6.6 billion people
and more than $65 trillion in annual economic output without the vast network of
dams, reservoirs, pumps, canals and other water infrastructure now in place. These
projects, however, have often failed to distribute benefits equitably and have resulted
in the degradation, or outright destruction, of natural freshwater ecosystems that in
their healthy state provide valuable goods and services to society.