Our nation's built infrastructure—our water supply and wastewater treatment systems, roads and bridges, railroads, and energy production and delivery systems—needs repair and modernization. At the same time, our natural infrastructure—our forests, prairies, wetlands, streams, rivers, estuaries, and shorelines—are in even greater need of repair. Once restored, these natural infrastructures and ecosystems can address pressing national problems: the need to conserve energy, improve water quality and reduce coastal hypoxia, decrease flood damage, and address global warming.