Water infrastructure was not designed for past climate extremes, let alone future changes, report authors say.
Putting human health, life, and jobs at risk, a reliable supply of clean water for cities, farms, industries, and ecosystems in the United States while also managing droughts and floods is “increasingly in jeopardy,” according to an expansive U.S. government report on the consequences of climate change in the country.
The National Climate Assessment, required by an act of Congress and written by more than 300 scientists, half from outside the federal government, is meant to inform U.S. leaders about changes to land, water, and air from a warming planet.
Released the day after Thanksgiving, the report focuses on how those physical changes will dramatically reshape human life and the systems that support it. The report also underscores troubling knowledge gaps about how the projected increase in extreme storms and heat will affect the nation’s water supply.
“We don’t have a very good grasp as a nation what our water-related risks are,” Casey Brown, a co-author on the report’s water chapter, told Circle of Blue. “We seem to keep learning this every time there’s a flood or drought.”
The authors of the water chapter emphasized three elements of the interaction between climate change and man-made systems: water quality and availability will shift; dams, levees, drainage systems, and other components of the nation’s water infrastructure are aging and poorly designed for a topsy-turvy climate; and water managers will need to prepare for a broader set of climate stresses.
“You could talk about a lot of impacts to water,” Upmanu Lall, lead author of the report’s water chapter, told Circle of Blue. “We chose to talk about infrastructure because no one is highlighting that.”
Physical alterations to the country’s water supplies, many of which are already happening, will be far-reaching, the report says. On the coasts and islands, rising seas will drive saltwater farther inland underground, which will worsen flooding and spoil groundwater used for irrigation and drinking water.