Spurred by disasters like Hurricane Katrina and Superstorm Sandy, cities across the United States have, over the past 15 years, learned to “live with water.” After more than a century of filling wetlands, damming rivers, and diverting streams and stormwater flows into concrete channels, public officials, influenced by a coterie of landscape architects and planners, have embraced the opposite strategy, investing in open space networks that use dynamic natural systems to slow, store, and absorb floodwaters.