Water securityNational Climate Assessment: Will U.S. water problems worsen?

Published 5 December 2018

Upmanu Lall is director of the Columbia Water Center, chair of Earth and Environmental Engineering, and the lead author of the chapter on water resources in the latest U.S. National Climate Assessment. The report, issued two weeks ago, paints a troubling picture of the nation’s climate future, including projected droughts and extreme precipitation events that could worsen already existing problems with U.S. water supplies and infrastructure. Lall discusses the climate change-driven water challenges the U.S. faces, and ideas for how the nation can respond.

Upmanu Lall is director of the Columbia Water Center, chair of Earth and Environmental Engineering, and the lead author of the chapter on water resources in the latest U.S. National Climate Assessment. The report, issued two weeks ago, paints a troubling picture of the nation’s climate future, including projected droughts and extreme precipitation events that could worsen already existing problems with U.S. water supplies and infrastructure. State of the Planet’s Kevin Krajick spoke with Lall about the challenges, and ideas for how the nation can respond.

Kevin Krajick: Your chapter in the National Climate Assessment says that infrastructure for storing and delivering water is already outdated, and new investments are not keeping up. Could climate change compound this problem?
Upmanu Lall
:  Current water infrastructure is beyond its design life. Plus, system operations and allocation rules do not account for a changing climate, nor even for the range of droughts and floods experienced over the last 1,000 years. As a result, we face compound risks. A major dam failure due to overtopping could lead to a cascading failure of downstream dams and levees, thermoelectric power plants, water and wastewater treatment systems, and transportation networks, including airports, which are often sited near rivers. Regionally, one could experience severe drought and flood in the same year or in succession, as we have seen in Texas and California recently. We have no planning to address the joint risk of such events. We could face a perfect storm in some part of the United States. Just last February, we saw the near failure of the tallest U.S. dam, in Oroville, Calif.

Federal investments in water infrastructure today are lower in real dollars than they were in 1983. Local and state financing has gone up, but it has not covered the gap. This has led to significant fragmentation of planning and investment, so that only very local projects are typically looked at. Since the local ability to pay is limited, aging systems continue to be operated with deferred maintenance.