William Mulholland got a famous street named after him, but, more importantly, he brought water to thirsty Los Angeles. Unfortunately, the St. Francis Dam, which he built 50 miles from the city, failed in 1928, sending billions of gallons of water rushing down the San Francisquito Canyon, killing 500 people and costing millions in damages. In Floodpath: The Deadliest Man-Made Disaster of 20th Century America and the Making of Los Angeles (Bloomsbury, $28), Jon Wilkman weaves the story of the disaster with the history of SoCal’s need for water and what the region’s done to get it. It’s a welcome addition to California’s water histories, where drought and scarcity always make somebody think building a dam is a good idea.