The massive dams of the American West were designed to serve multiple purposes: improving navigation, irrigating crops, storing water, controlling floods, and generating hydroelectricity. Their construction also put thousands of people to work during the Great Depression. Only later did the dams baneful effects on river ecologies spark public debate.

Big Dams of the New Deal Era tells how major water-storage structures were erected in four western river basins. David P. Billington and Donald C. Jackson reveal how engineering science, regional and national politics, perceived...