Thomas M. Johnson
Peter Colohan
Amir AghaKouchak
Casey L. Brown
Gregory J. McCabe
Roger Pulwarty
Sankar Arumugam
David Reidmiller
C. W. Avery
D. R. Easterling
K. E. Kunkel
K. L. M. Lewis
T. K. Maycock
B. C. Stewart
Upmanu Lall
2018
<p>Ensuring a reliable supply of clean freshwater to individuals, communities, and<span> </span><a class="glossarizer_replaced" title="" data-toggle="tooltip" data-hasqtip="27" data-mce-tabindex="0">ecosystems</a>, together with effective management of floods and droughts, is the foundation of human and ecological health. The water sector is also central to the economy and contributes significantly to the resilience of many other sectors, including agriculture, energy, urban environments, and industry.</p><p>Water systems face considerable<span> </span><a class="glossarizer_replaced" title="Risks are threats to life, health and safety, the environment, economic well-being, and other things of value. Risks are often evaluated in terms of how likely they are to occur (probability) and the damages that would result if they did happen (consequences)." data-toggle="tooltip" data-mce-tabindex="0">risk</a>, even without anticipated future climate changes. Limited surface water storage, as well as a limited ability to make use of long-term drought forecasts and to trade water across uses and basins, has led to a significant depletion of aquifers in many regions in the United States.<sup id="fnref:a0d8099d-7c6d-405b-8f12-4c77318f32f5"></sup><span> </span>Across the Nation, much of the critical water and wastewater infrastructure is nearing the end of its useful life. To date, no comprehensive assessment exists of the climate-related<span> </span><a class="glossarizer_replaced" title="" data-toggle="tooltip" data-hasqtip="19" aria-describedby="qtip-19" data-mce-tabindex="0">vulnerability</a><span> </span>of U.S. water infrastructure (including dams, levees, aqueducts, sewers, and water and wastewater distribution and treatment systems), the potential resulting damages, or the cost of reconstruction and recovery. Paleoclimate information (reconstructions of past climate derived from ice cores or tree rings) shows that over the last 500 years, North America has experienced pronounced wet/dry regime shifts that sometimes persisted for decades.<sup id="fnref:ccb91f7a-b26a-412a-a084-e7fe2cd741f4"></sup><span> </span>Because such protracted exposures to extreme floods or droughts in different parts of the country are extraordinary compared to events experienced in the 20th century, they are not yet incorporated in water management principles and practice. Anticipated future<span> </span><a class="glossarizer_replaced" title="Changes in average weather conditions that persist over multiple decades or longer. Climate change encompasses both increases and decreases in temperature, as well as shifts in precipitation, changing risk of certain types of severe weather events, and changes to other features of the climate system. [See also global change]" data-toggle="tooltip" data-mce-tabindex="0">climate change</a><span> </span>will exacerbate this risk in many regions.</p><p>A central challenge to water planning and management is learning to plan for plausible future climate conditions that are wider in range than those experienced in the 20th century. Doing so requires approaches that evaluate plans over many possible futures instead of just one, incorporate real-time monitoring and forecast products to better manage extremes when they occur, and update policies and engineering principles with the best available geoscience-based understanding of planetary change. While this represents a break from historical practice, recent examples of<span> </span><a class="glossarizer_replaced" title="Adjustment in natural or human systems to a new or changing environment that exploits beneficial opportunities or moderates negative effects." data-toggle="tooltip" data-mce-tabindex="0">adaptation</a><span> </span>responses undertaken by large water management agencies, including major metropolitan water utilities and the U.S. Army Corps of Engineers, are promising.</p>
application/pdf
10.7930/NCA4.2018.CH3
en
U.S. Global Change Research Program
Water
reports