We’ve got a dam problem. From gargantuan monstrosities like the Hoover, to modest diversion dams in your backyard creek, America’s waterways are choked with concrete. It’s estimated that the total number of dams in the United States may exceed one million, and in Cracked (Patagonia, $28), we get the whole dam story. Why did we build so many dams in the first place? What environmental and ecological issues are we facing as a result? What can we do about it—and what will happen if we do nothing? Taking examples from around the world of successful river-restoration projects—along with disastrous dam failures—author Steven Hawley not only makes a compelling case for dam removal, but also provides a step-by-step manual on how to do it. It’s not an easy task, but Hawley points out that when dams come out, rivers tend to restore to their natural ecological state within merely a year. So crack open this book, and take a swing at your local jammed-up watershed.