A word about dams: Each dam, from largest to smallest, contributes to an overall effort to control and direct water resources. Smaller dams, although constructed to serve a specific purpose, may well have several uses, including recreation. There are literally thousands of small dams in cities and towns across America and amount to the most far-flung natural resource development program the nation has ever undertaken.

Success is often determined by how well a dam serves its purpose - whether generating power, controlling floods, or irrigating crops - without causing undue environmental harm.