Book excerpt: California Rivers and Streams provides a clear and informative overview of the physical and biological processes that shape California's rivers and watersheds. Jeffrey Mount introduces relevant basic principles of hydrology and geomorphology and applies them to an understanding of the differences in character of the state's many rivers. He then builds on this foundation by evaluating the impact on waterways of different land use practices—logging, mining, agriculture, flood control, urbanization, and water supply development. Water may be one of California's most valuable resources, but it is far from being one we control. In spite of channels, levees, lines and dams, the state's rivers still frequently flood, with devastating results. Almost all the rivers in California are dammed or diverted; with the booming population, there will be pressure for more intervention. Mount argues that Californians know little about how their rivers work and, more importantly, how and why land-use practices impact rivers. The forceful reconfiguration and redistribution of the rivers has already brought the state to a critical crossroads. California Rivers and Streams forces us to reevaluate our use of the state's rivers and offers a foundation for participating in the heated debates about their future.