Sandra Postel is director of the Global Water Policy Project and author of Replenish: The Virtuous Cycle of Water and Prosperity. She co-created Change the Course, the national water stewardship initiative awarded the 2017 US Water Prize for restoring billions of gallons of water to depleted rivers and wetlands. From 2009-2015, she served as Freshwater Fellow of the National Geographic Society. Sandra is author of Pillar of Sand: Can the Irrigation Miracle Last? and of Last Oasis, the basis for a PBS documentary. Her work has appeared in Science, Natural History, and Best American Science and Nature Writing.
Large dams, diversions, flood-control levees and other feats of engineering have brought enormous prosperity to the world. But they have also broken the water cycle – the way natural systems move, store and cleanse water. Especially as droughts, floods and wildfires intensify, a healthier water cycle is critical to water security.
Fortunately, with innovation and collaboration, we can re-shape 21st century water management to meet the challenges ahead. Irrigation upgrades in Arizona’s Verde River Valley have doubled summertime flow in critical reaches, while boosting the local economy. US farmers are adopting practices that sequester carbon, expand the soil’s water reservoir, and reduce polluted runoff. And China’s “sponge cities” are capturing rainwater to curb urban flooding and mitigate droughts.
If the 20th century was the age of dams, diversions and depletion, the 21st century can be the age of replenishment, the time when we build water security and resilience to climate change by working more with nature rather than against it.