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  • Review Article
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A low-to-no snow future and its impacts on water resources in the western United States

Nature Reviews Earth & Environment volume 2, pages 800–819 (2021)Cite this article

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Abstract

Anthropogenic climate change is decreasing seasonal snowpacks globally, with potentially catastrophic consequences on water resources, given the long-held reliance on snowpack in water management. In this Review, we examine the changes and trickle-down impacts of snow loss in the western United States (WUS). Across the WUS, snow water equivalent declines of ~25% are expected by 2050, with losses comparable with contemporary historical trends. There is less consensus on the time horizon of snow disappearance, but model projections combined with a new low-to-no snow definition suggest ~35–60 years before low-to-no snow becomes persistent if greenhouse gas emissions continue unabated. Diminished and more ephemeral snowpacks that melt earlier will alter groundwater and streamflow dynamics. The direction of these changes are difficult to constrain given competing factors such as higher evapotranspiration, altered vegetation composition and changes in wildfire behaviour in a warmer world. These changes undermine conventional WUS water management practices, but through proactive implementation of soft and hard adaptation strategies, there is potential to build resilience to extreme, episodic and, eventually, persistent low-to-no snow conditions. Federal investments offer a timely opportunity to address these vulnerabilities, but they require a concerted portfolio of activities that cross historically siloed physical and disciplinary boundaries.

Key points

  • Mountain snowpacks in the western United States (WUS) have historically acted as large, natural reservoirs of water; yet, they are now harbingers of a changing climate through their signalling of a low-to-no snow future.

  • Models projecting the time horizon of low-to-no snow in the WUS lack spatiotemporal consensus due to differences in definitions, metrics, methods and regionally specific analyses.

  • Low-to-no snow will impose a series of cascading hydrologic changes to the water–energy balance, including vegetation processes, surface and subsurface water storage and, ultimately, streamflow that directly impacts water management.

  • A re-evaluation of long-standing hydroclimatic stationarity assumptions in WUS water management is urgently needed, given the impending trickle-down impacts of a low-to-no snow future.

  • Observational and modelling advances are needed to better understand the implications of a low-to-no snow future on water resources and to evaluate the trade-offs among a wide array of potential adaptation strategies that can address both water supply availability and water demands.

  • Co-production of knowledge between scientists and water managers can help to ensure that scientific advances provide actionable insight and support adaptation decision-making processes that unfold in the context of significant uncertainties about future conditions.

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Fig. 1: Spatiotemporal variability in western United States seasonal snowpack.
Fig. 2: A multiscale perspective of the mountainous hydrologic cycle.
Fig. 3: Ranges of projected twenty-first century snowpack loss.
Fig. 4: Snow disappearance based on a low-to-no snow definition.
Fig. 5: Changes in mountain environments under persistent low-to-no snow conditions.
Fig. 6: Cascading above and below ground impacts of snowpack changes.
Fig. 7: Supply and demand connections between the natural and managed WUS water systems.

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References

  1. Huss, M. et al. Toward mountains without permanent snow and ice. Earths Future 5, 418–435 (2017).

    Article  Google Scholar 

  2. Immerzeel, W. W. et al. Importance and vulnerability of the world’s water towers. Nature 577, 364–369 (2020).

    Article  Google Scholar 

  3. Gergel, D. R., Nijssen, B., Abatzoglou, J. T., Lettenmaier, D. P. & Stumbaugh, M. R. Effects of climate change on snowpack and fire potential in the western USA. Clim. Change 141, 287–299 (2017).

    Article  Google Scholar 

  4. Sturm, M., Goldstein, M. A. & Parr, C. Water and life from snow: a trillion dollar science question. Water Resour. Res. 53, 3534–3544 (2017).

    Article  Google Scholar 

  5. Dettinger, M. D. & Anderson, M. L. Storage in California’s reservoirs and snowpack in this time of drought. San Franc. Estuary Watershed Sci. 13, 1 (2015).

    Google Scholar 

  6. Qin, Y. et al. Agricultural risks from changing snowmelt. Nat. Clim. Chang. 10, 459–465 (2020).

    Article  Google Scholar 

  7. Rhoades, A. M., Ullrich, P. A. & Zarzycki, C. M. Projecting 21st century snowpack trends in western USA mountains using variable-resolution CESM. Clim. Dyn. 50, 261–288 (2018).

    Article  Google Scholar 

  8. Pierce, D. W. et al. Probabilistic estimates of future changes in California temperature and precipitation using statistical and dynamical downscaling. Clim. Dyn. 40, 839–856 (2013).

    Article  Google Scholar 

  9. Marshall, A. M., Abatzoglou, J. T., Link, T. E. & Tennant, C. J. Projected changes in interannual variability of peak snowpack amount and timing in the Western United States. Geophys. Res. Lett. 46, 8882–8892 (2019).

    Article  Google Scholar 

  10. Barnett, T. P., Adam, J. C. & Lettenmaier, D. P. Potential impacts of a warming climate on water availability in snow-dominated regions. Nature 438, 303–309 (2005).

    Article  Google Scholar 

  11. Allan, R. P. et al. Advances in understanding large-scale responses of the water cycle to climate change. Ann. NY Acad. Sci. 1472, 49–75 (2020).

    Article  Google Scholar 

  12. Huning, L. S. & AghaKouchak, A. Global snow drought hot spots and characteristics. Proc. Natl Acad. Sci. USA 117, 19753–19759 (2020).

    Article  Google Scholar 

  13. Polade, S. D., Gershunov, A., Cayan, D. R., Dettinger, M. D. & Pierce, D. W. Precipitation in a warming world: assessing projected hydro-climate changes in California and other Mediterranean climate regions. Sci. Rep. 7, 10783 (2017).

    Article  Google Scholar 

  14. Milly, P. C. D. & Dunne, K. A. Colorado River flow dwindles as warming-driven loss of reflective snow energizes evaporation. Science 367, 1252–1255 (2020).

    Article  Google Scholar 

  15. Mote, P. W., Li, S., Lettenmaier, D. P., Xiao, M. & Engel, R. Dramatic declines in snowpack in the western US. npj Clim. Atmos. Sci. 1, 2 (2018).

    Article  Google Scholar 

  16. Mountain Research Initiative EDW Working Group. Elevation-dependent warming in mountain regions of the world. Nat. Clim. Chang. 5, 424–430 (2015).

    Article  Google Scholar 

  17. US Global Change Research Program. Climate science special report: fourth national climate assessment, Vol. I (USGCRP, 2017).

  18. Rhoades, A. M., Jones, A. D. & Ullrich, P. A. Assessing mountains as natural reservoirs with a multimetric framework. Earths Future 6, 1221–1241 (2018).

    Article  Google Scholar 

  19. Milly, P. C. D. et al. Stationarity is dead: whither water management? Earth 4, 20 (2008).

    Google Scholar 

  20. Vano, J. A. Implications of losing snowpack. Nat. Clim. Chang. 10, 388–390 (2020).

    Article  Google Scholar 

  21. Ullrich, P. A. et al. California’s drought of the future: a midcentury recreation of the exceptional conditions of 2012–2017. Earths Future 6, 1568–1587 (2018).

    Article  Google Scholar 

  22. Livneh, B. & Badger, A. M. Drought less predictable under declining future snowpack. Nat. Clim. Chang. 10, 452–458 (2020).

    Article  Google Scholar 

  23. US Geophysics Research Forum & Geophysics Study Committee. Scientific Basis of Water-resource Management (National Academy, 1982).

  24. Hatchett, B. J., Boyle, D. P., Putnam, A. E. & Bassett, S. D. Placing the 2012–2015 California-Nevada drought into a paleoclimatic context: Insights from Walker Lake, California-Nevada, USA. Geophys. Res. Lett. 42, 8632–8640 (2015).

    Article  Google Scholar 

  25. Hatchett, B. J. et al. in From Saline to Freshwater: The Diversity of Western Lakes in Space and Time, Geological Society of America Special Paper Vol. 536 (eds Starratt, S. W. & Rosen, M. R.) 67–79 (Geological Society of America, 2019).

  26. Woodhouse, C. A., Kunkel, K. E., Easterling, D. R. & Cook, E. R. The twentieth-century pluvial in the western United States. Geophys. Res. Lett. 32, L07701 (2005).

    Article  Google Scholar 

  27. Cook, B. I., Seager, R. & Miller, R. L. On the causes and dynamics of the early twentieth-century North American pluvial. J. Clim. 24, 5043–5060 (2011).

    Article  Google Scholar 

  28. Kreutz, K. J. et al. Bipolar changes in atmospheric circulation during the Little Ice Age. Science 277, 1294–1296 (1997).

    Article  Google Scholar 

  29. Hatchett, B. J. & McEvoy, D. J. Exploring the origins of snow drought in the northern Sierra Nevada, California. Earth Interact. 22, 1–13 (2018).

    Article  Google Scholar 

  30. Noble, P. J. et al. Holocene paleoclimate history of Fallen Leaf Lake, CA., from geochemistry and sedimentology of well-dated sediment cores. Quat. Sci. Rev. 131, 193–210 (2016).

    Article  Google Scholar 

  31. Shuman, B. N. & Serravezza, M. Patterns of hydroclimatic change in the Rocky Mountains and surrounding regions since the last glacial maximum. Quat. Sci. Rev. 173, 58–77 (2017).

    Article  Google Scholar 

  32. Bacon, S. N., Lancaster, N., Stine, S., Rhodes, E. J. & McCarley Holder, G. A. A continuous 4000-year lake-level record of Owens Lake, south-central Sierra Nevada, California, USA. Quat. Res. 90, 276–302 (2018).

    Article  Google Scholar 

  33. Sterle, K. & Singletary, L. Adapting to variable water supply in the Truckee-Carson river system, western USA. Water 9, 768 (2017).

    Article  Google Scholar 

  34. Hossain, F. et al. What do experienced water managers think of water resources of our nation and its management infrastructure? PLoS ONE 10, e0142073 (2015).

    Article  Google Scholar 

  35. Lynn, E. et al. Technical note: Precipitation-phase partitioning at landscape scales to regional scales. Hydrol. Earth Syst. Sci. 24, 5317–5328 (2020).

    Article  Google Scholar 

  36. Nolin, A. W. & Daly, C. Mapping “at risk” snow in the Pacific Northwest. J. Hydrometeorol. 7, 1164–1171 (2006).

    Article  Google Scholar 

  37. Mott, R., Vionnet, V. & Grünewald, T. The seasonal snow cover dynamics: review on wind-driven coupling processes. Front. Earth Sci. 6, 197 (2018).

    Article  Google Scholar 

  38. Shafer, S. L., Bartlein, P. J. & Whitlock, C. in Global Change and Mountain Regions: An Overview of Current Knowledge (eds Huber, U. M., Bugmann, H. K. M. & Reasoner, M. A.) 21–30 (Springer, 2005).

  39. Maina, F. Z., Siirila-Woodburn, E. R., Newcomer, M., Xu, Z. & Steefel, C. Determining the impact of a severe dry to wet transition on watershed hydrodynamics in California, USA with an integrated hydrologic model. J. Hydrol. 580, 124358 (2020).

    Article  Google Scholar 

  40. Meixner, T. et al. Implications of projected climate change for groundwater recharge in the western United States. J. Hydrol. 534, 124–138 (2016).

    Article  Google Scholar 

  41. Jagannathan, K. et al. Great expectations? Reconciling the aspiration, outcome, and possibility of co-production. Curr. Opin. Environ. Sustain. 42, 22–29 (2020).

    Article  Google Scholar 

  42. Jagannathan, K., Jones, A. D. & Ray, I. The making of a metric: co-producing decision-relevant climate science. Bull. Am. Meteorol. Soc. 102, E1579–E1590 (2021).

    Article  Google Scholar 

  43. Neelin, J. D., Langenbrunner, B., Meyerson, J. E., Hall, A. & Berg, N. California winter precipitation change under global warming in the Coupled Model Intercomparison Project phase 5 ensemble. J. Clim. 26, 6238–6256 (2013).

    Article  Google Scholar 

  44. Dong, L., Leung, L. R., Lu, J. & Song, F. Double‐ITCZ as an emergent constraint for future precipitation over Mediterranean climate regions in the North Hemisphere. Geophys. Res. Lett. 48, e2020GL091569 (2021).

    Article  Google Scholar 

  45. Persad, G. G., Swain, D. L., Kouba, C. & Ortiz-Partida, J. P. Inter-model agreement on projected shifts in California hydroclimate characteristics critical to water management. Clim. Change 162, 1493–1513 (2020).

    Article  Google Scholar 

  46. Helms, D., Phillips, S. E. & Reich, P. F. The History of Snow Survey and Water Supply Forecasting: Interviews with U.S. Department of Agriculture Pioneers (US Department of Agriculture, 2008).

  47. Huning, L. S. & AghaKouchak, A. Approaching 80 years of snow water equivalent information by merging different data streams. Sci. Data 7, 333 (2020).

    Article  Google Scholar 

  48. Evan, A. T. A new method to characterize changes in the seasonal cycle of snowpack. J. Appl. Meteorol. Climatol. 58, 131–143 (2019).

    Article  Google Scholar 

  49. Margulis, S. A., Liu, Y. & Baldo, E. A joint landsat- and MODIS-based reanalysis approach for midlatitude montane seasonal snow characterization. Front. Earth Sci. 7, 272 (2019).

    Article  Google Scholar 

  50. Kapnick, S. & Hall, A. Causes of recent changes in western North American snowpack. Clim. Dyn. 38, 1885–1899 (2012).

    Article  Google Scholar 

  51. Kapnick, S. & Hall, A. Observed climate–snowpack relationships in California and their implications for the future. J. Clim. 23, 3446–3456 (2010).

    Article  Google Scholar 

  52. Margulis, S. A. et al. Characterizing the extreme 2015 snowpack deficit in the Sierra Nevada (USA) and the implications for drought recovery. Geophys. Res. Lett. 43, 6341–6349 (2016).

    Article  Google Scholar 

  53. Margulis, S. A., Cortés, G., Girotto, M. & Durand, M. A Landsat-era Sierra Nevada snow reanalysis (1985–2015). J. Hydrometeorol. 17, 1203–1221 (2016).

    Article  Google Scholar 

  54. Hatchett, B. J. Seasonal and ephemeral snowpacks of the conterminous United States. Hydrology 8, 32 (2021).

    Article  Google Scholar 

  55. Bohr, G. S. & Aguado, E. Use of April 1 SWE measurements as estimates of peak seasonal snowpack and total cold-season precipitation. Water Resour. Res. 37, 51–60 (2001).

    Article  Google Scholar 

  56. Hatchett, B. J., Rhoades, A. M. & McEvoy, D. J. Monitoring the daily evolution and extent of snow drought. Preprint at Nat. Hazards Earth Syst. Sci. https://doi.org/10.5194/nhess-2021-193 (2021).

  57. Harpold, A., Dettinger, M. & Rajagopal, S. Defining snow drought and why it matters. Eos https://doi.org/10.1029/2017eo068775 (2017).

    Article  Google Scholar 

  58. Dierauer, J. R., Allen, D. M. & Whitfield, P. H. Snow drought risk and susceptibility in the western United States and southwestern Canada. Water Resour. Res. 55, 3076–3091 (2019).

    Article  Google Scholar 

  59. Rasmussen, R. et al. How well are we measuring snow: the NOAA/FAA/NCAR winter precipitation test bed. Bull. Am. Meteorol. Soc. 93, 811–829 (2012).

    Article  Google Scholar 

  60. Kinar, N. J. & Pomeroy, J. W. Measurement of the physical properties of the snowpack. Rev. Geophys. 53, 481–544 (2015).

    Article  Google Scholar 

  61. Lundquist, J., Hughes, M., Gutmann, E. & Kapnick, S. Our skill in modeling mountain rain and snow is bypassing the skill of our observational networks. Bull. Am. Meteorol. Soc. 100, 2473–2490 (2019).

    Article  Google Scholar 

  62. McNeeley, S. M. et al. Anatomy of an interrupted irrigation season: micro-drought at the Wind River Indian Reservation. Clim. Risk Manag. 19, 61–82 (2018).

    Article  Google Scholar 

  63. Huning, L. S. & AghaKouchak, A. Mountain snowpack response to different levels of warming. Proc. Natl Acad. Sci. USA 115, 10932–10937 (2018).

    Article  Google Scholar 

  64. Wrzesien, M. L., Pavelsky, T. M., Durand, M. T., Dozier, J. & Lundquist, J. D. Characterizing biases in mountain snow accumulation from global data sets. Water Resour. Res. 55, 9873–9891 (2019).

    Article  Google Scholar 

  65. Painter, T. H. et al. The Airborne Snow Observatory: fusion of scanning lidar, imaging spectrometer, and physically-based modeling for mapping snow water equivalent and snow albedo. Remote Sens. Environ. 184, 139–152 (2016).

    Article  Google Scholar 

  66. Guan, B. et al. Snow water equivalent in the Sierra Nevada: blending snow sensor observations with snowmelt model simulations. Water Resour. Res. 49, 5029–5046 (2013).

    Article  Google Scholar 

  67. Rittger, K., Bair, E. H., Kahl, A. & Dozier, J. Spatial estimates of snow water equivalent from reconstruction. Adv. Water Resour. 94, 345–363 (2016).

    Article  Google Scholar 

  68. Crumley, R. L. et al. Assimilation of citizen science data in snowpack modeling using a new snow dataset: Community Snow Observations. Hydrol. Earth Syst. Sci. 25, 4651–4680 (2021).

    Article  Google Scholar 

  69. Musselman, K. N., Addor, N., Vano, J. A. & Molotch, N. P. Winter melt trends portend widespread declines in snow water resources. Nat. Clim. Chang. 1, 418–424 (2021).

    Article  Google Scholar 

  70. Harpold, A. et al. Changes in snowpack accumulation and ablation in the intermountain west. Water Resour. Res. 48, W11501 (2012).

    Article  Google Scholar 

  71. Mote, P. W., Hamlet, A. F. & Clark, M. P. Declining mountain snowpack in western North America. Bull. Am. Meteorol. Soc. 86, 39–50 (2005).

    Article  Google Scholar 

  72. Michelle Hu, J. & Nolin, A. W. Widespread warming trends in storm temperatures and snowpack fate across the Western United States. Environ. Res. Lett. 15, 034059 (2020).

    Article  Google Scholar 

  73. Gonzales, K. R., Swain, D. L., Nardi, K. M., Barnes, E. A. & Diffenbaugh, N. S. Recent warming of landfalling atmospheric rivers along the west coast of the United States. J. Geophys. Res. 24, 6810–6826 (2019).

    Article  Google Scholar 

  74. Payne, A. E. et al. Responses and impacts of atmospheric rivers to climate change. Nat. Rev. Earth Environ. 1, 143–157 (2020).

    Article  Google Scholar 

  75. Oyler, J. W., Dobrowski, S. Z., Ballantyne, A. P., Klene, A. E. & Running, S. W. Artificial amplification of warming trends across the mountains of the western United States. Geophys. Res. Lett. 42, 153–161 (2015).

    Article  Google Scholar 

  76. Wayand, N. E., Lundquist, J. D. & Clark, M. P. Modeling the influence of hypsometry, vegetation, and storm energy on snowmelt contributions to basins during rain‐on‐snow floods. Water Resour. Res. 51, 8551–8569 (2015).

    Article  Google Scholar 

  77. McCabe, G. J., Clark, M. P. & Hay, L. E. Rain-on-snow events in the western United States. Bull. Am. Meteorol. Soc. 88, 319–328 (2007).

    Article  Google Scholar 

  78. Skiles, S. M., Flanner, M., Cook, J. M., Dumont, M. & Painter, T. H. Radiative forcing by light-absorbing particles in snow. Nat. Clim. Chang. 8, 964–971 (2018).

    Article  Google Scholar 

  79. Gleason, K. E., McConnell, J. R., Arienzo, M. M., Chellman, N. & Calvin, W. M. Four-fold increase in solar forcing on snow in western US burned forests since 1999. Nat. Commun. 10, 2026 (2019).

    Article  Google Scholar 

  80. AghaKouchak, A. et al. How do natural hazards cascade to cause disasters? Nature 561, 458–460 (2018).

    Article  Google Scholar 

  81. Parks, S. A. & Abatzoglou, J. T. Warmer and drier fire seasons contribute to increases in area burned at high severity in western US forests from 1985 to 2017. Geophys. Res. Lett. 47, e2020GL089858 (2020).

    Article  Google Scholar 

  82. Neff, J. C. et al. Increasing eolian dust deposition in the western United States linked to human activity. Nat. Geosci. 1, 189–195 (2008).

    Article  Google Scholar 

  83. Skiles, S. M. et al. Implications of a shrinking Great Salt Lake for dust on snow deposition in the Wasatch Mountains, UT, as informed by a source to sink case study from the 13–14 April 2017 dust event. Environ. Res. Lett. 13, 124031 (2018).

    Article  Google Scholar 

  84. Delaney, C. J. et al. Forecast informed reservoir operations using ensemble streamflow predictions for a multipurpose reservoir in northern California. Water Resour. Res. 56, e2019WR026604 (2020).

    Article  Google Scholar 

  85. Roberts, M., Milman, A. & Blomquist, W. in Water Resilience: Management and Governance in Times of Change (eds Baird, J. & Plummer, R.) 41–63 (Springer, 2021).

  86. Maina, F. Z., Siirila-Woodburn, E. R. & Vahmani, P. Sensitivity of meteorological-forcing resolution on hydrologic variables. Hydrol. Earth Syst. Sci. 24, 3451–3474 (2020).

    Article  Google Scholar 

  87. Randall, D. A. et al. 100 years of earth system model development. Meteorol. Monogr. 59, 12.1–12.66 (2018).

    Article  Google Scholar 

  88. Leutwyler, D., Fuhrer, O., Lapillonne, X., Lüthi, D. & Schär, C. Towards European-scale convection-resolving climate simulations with GPUs: a study with COSMO 4.19. Geosci. Model Dev. 9, 3393–3412 (2016).

    Article  Google Scholar 

  89. Schär, C. et al. Kilometer-scale climate models: prospects and challenges. Bull. Am. Meteorol. Soc. 101, E567–E587 (2020).

    Article  Google Scholar 

  90. Satoh, M. et al. Global cloud-resolving models. Curr. Clim. Change Rep. 5, 172–184 (2019).

    Article  Google Scholar 

  91. Martin Ralph, F. et al. West Coast forecast challenges and development of atmospheric river reconnaissance. Bull. Am. Meteorol. Soc. 101, E1357–E1377 (2020).

    Article  Google Scholar 

  92. Ralph, F. M. et al. A vision for future observations for western U.S. extreme precipitation and flooding. J. Contemp. Water Res. Educ. 153, 16–32 (2014).

    Article  Google Scholar 

  93. Hatchett, B. J. et al. Observations of an extreme atmospheric river storm with a diverse sensor network. Earth Space Sci. 7, e2020EA001129 (2020).

    Article  Google Scholar 

  94. White, A. B. et al. A twenty-first-century California observing network for monitoring extreme weather events. J. Atmos. Ocean. Technol. 30, 1585–1603 (2013).

    Article  Google Scholar 

  95. Shen, C. A transdisciplinary review of deep learning research and its relevance for water resources scientists. Water Resour. Res. 54, 8558–8593 (2018).

    Article  Google Scholar 

  96. Schneider, T., Lan, S., Stuart, A. & Teixeira, J. Earth system modeling 2.0: a blueprint for models that learn from observations and targeted high‐resolution simulations. Geophys. Res. Lett. 44, 12,396–12,417 (2017).

    Article  Google Scholar 

  97. Yang, Q. et al. Exploring the effects of a nonhydrostatic dynamical core in high-resolution aquaplanet simulations. J. Geophys. Res. 122, 3245–3265 (2017).

    Article  Google Scholar 

  98. Arakawa, A. & Jung, J.-H. Multiscale modeling of the moist-convective atmosphere — A review. Atmos. Res. 102, 263–285 (2011).

    Article  Google Scholar 

  99. Gross, M. et al. Physics–dynamics coupling in weather, climate, and earth system models: challenges and recent progress. Mon. Weather. Rev. 146, 3505–3544 (2018).

    Article  Google Scholar 

  100. Harris, L. M., Lin, S.-J. & Tu, C. High-resolution climate simulations using GFDL HiRAM with a stretched global grid. J. Clim. 29, 4293–4314 (2016).

    Article  Google Scholar 

  101. Zarzycki, C. M., Jablonowski, C. & Taylor, M. A. Using variable-resolution meshes to model tropical cyclones in the community atmosphere model. Mon. Weather Rev. 142, 1221–1239 (2014).

    Article  Google Scholar 

  102. Rauscher, S. A. & Ringler, T. D. Impact of variable-resolution meshes on midlatitude baroclinic eddies using CAM-MPAS-A. Mon. Weather. Rev. 142, 4256–4268 (2014).

    Article  Google Scholar 

  103. Rhoades, A. M., Huang, X., Ullrich, P. A. & Zarzycki, C. M. Characterizing Sierra Nevada snowpack using variable-resolution CESM. J. Appl. Meteorol. Climatol. 55, 173–196 (2016).

    Article  Google Scholar 

  104. Ghan, S. J. & Shippert, T. Physically based global downscaling: climate change projections for a full century. J. Clim. 19, 1589–1604 (2006).

    Article  Google Scholar 

  105. Qian, Y., Ghan, S. J. & Leung, L. R. Downscaling hydroclimatic changes over the Western US based on CAM subgrid scheme and WRF regional climate simulations. Int. J. Climatol. 30, 675–693 (2009).

    Google Scholar 

  106. Clark, M. P. et al. A unified approach for process‐based hydrologic modeling: 2. Model implementation and case studies. Water Resour. Res. 51, 2515–2542 (2015).

    Article  Google Scholar 

  107. Fisher, R. A. & Koven, C. D. Perspectives on the future of land surface models and the challenges of representing complex terrestrial systems. J. Adv. Model. Earth Syst. 12, e2018MS001453 (2020).

    Article  Google Scholar 

  108. Ning, L., Zhan, C., Luo, Y., Wang, Y. & Liu, L. A review of fully coupled atmosphere-hydrology simulations. J. Geogr. Sci. 29, 465–479 (2019).

    Article  Google Scholar 

  109. Smyth, E. J., Raleigh, M. S. & Small, E. E. Improving SWE estimation with data assimilation: the influence of snow depth observation timing and uncertainty. Water Resour. Res. 56, e2019WR026853 (2020).

    Article  Google Scholar 

  110. Margulis, S. A., Fang, Y., Li, D., Lettenmaier, D. P. & Andreadis, K. The utility of infrequent snow depth images for deriving continuous space‐time estimates of seasonal snow water equivalent. Geophys. Res. Lett. 46, 5331–5340 (2019).

    Article  Google Scholar 

  111. Krinner, G. et al. ESM-SnowMIP: assessing snow models and quantifying snow-related climate feedbacks. Geosci. Model Dev. 11, 5027–5049 (2018).

    Article  Google Scholar 

  112. Rhoades, A. M., Jones, A. D. & Ullrich, P. A. The changing character of the California Sierra Nevada as a natural reservoir. Geophys. Res. Lett. 45, 13,008–13,019 (2018).

    Article  Google Scholar 

  113. Pierce, D. W. & Cayan, D. R. The uneven response of different snow measures to human-induced climate warming. J. Clim. 26, 4148–4167 (2013).

    Article  Google Scholar 

  114. Fyfe, J. C. et al. Large near-term projected snowpack loss over the western United States. Nat. Commun. 8, 14996 (2017).

    Article  Google Scholar 

  115. Li, D., Wrzesien, M. L., Durand, M., Adam, J. & Lettenmaier, D. P. How much runoff originates as snow in the western United States, and how will that change in the future? Geophys. Res. Lett. 44, 6163–6172 (2017).

    Article  Google Scholar 

  116. López-Moreno, J. I. et al. Different sensitivities of snowpacks to warming in Mediterranean climate mountain areas. Environ. Res. Lett. 12, 074006 (2017).

    Article  Google Scholar 

  117. Rasmussen, R. et al. Climate change impacts on the water balance of the Colorado headwaters: high-resolution regional climate model simulations. J. Hydrometeorol. 15, 1091–1116 (2014).

    Article  Google Scholar 

  118. Alder, J. R. & Hostetler, S. W. The dependence of hydroclimate projections in snow‐dominated regions of the western United States on the choice of statistically downscaled climate data. Water Resour. Res. 55, 2279–2300 (2019).

    Article  Google Scholar 

  119. Leung, L. R. et al. Mid-century ensemble regional climate change scenarios for the western United States. Clim. Change 62, 75–113 (2004).

    Article  Google Scholar 

  120. Wrzesien, M. L. & Pavelsky, T. M. Projected changes to extreme runoff and precipitation events from a downscaled simulation over the western United States. Front. Earth Sci. 7, 355 (2020).

    Article  Google Scholar 

  121. Mahoney, K. et al. Cool season precipitation projections for California and the Western United States in NA-CORDEX models. Clim. Dyn. 56, 3081–3102 (2021).

    Article  Google Scholar 

  122. Musselman, K. N., Clark, M. P., Liu, C., Ikeda, K. & Rasmussen, R. Slower snowmelt in a warmer world. Nat. Clim. Chang. 7, 214–219 (2017).

    Article  Google Scholar 

  123. McCrary, R. R. & Mearns, L. O. Quantifying and diagnosing sources of uncertainty in midcentury changes in North American snowpack from NARCCAP. J. Hydrometeorol. 20, 2229–2252 (2019).

    Article  Google Scholar 

  124. Berg, N. & Hall, A. Anthropogenic warming impacts on California snowpack during drought. Geophys. Res. Lett. 44, 2511–2518 (2017).

    Article  Google Scholar 

  125. Gutowski, W. J. et al. The ongoing need for high-resolution regional climate models: process understanding and stakeholder information. Bull. Am. Meteorol. Soc. 101, E664–E683 (2020).

    Article  Google Scholar 

  126. Morss, R. E., Wilhelmi, O. V., Downton, M. W. & Gruntfest, E. Flood risk, uncertainty, and scientific information for decision making: lessons from an interdisciplinary project. Bull. Am. Meteorol. Soc. 86, 1593–1602 (2005).

    Article  Google Scholar 

  127. Svoboda, M. et al. The drought monitor. Bull. Am. Meteorol. Soc. 83, 1181–1190 (2002).

    Article  Google Scholar 

  128. Lehner, F. et al. Partitioning climate projection uncertainty with multiple large ensembles and CMIP5/6. Earth Syst. Dyn. 11, 491–508 (2020).

    Article  Google Scholar 

  129. Deser, C. et al. Insights from Earth system model initial-condition large ensembles and future prospects. Nat. Clim. Chang. 10, 277–286 (2020).

    Article  Google Scholar 

  130. Hausfather, Z. & Peters, G. P. Emissions–the ‘business as usual’ story is misleading. Nature 577, 618–620 (2020).

    Article  Google Scholar 

  131. Mizuta, R. et al. Climate simulations using MRI-AGCM3.2 with 20-km grid. J. Meteorol. Soc. Japan 90A, 233–258 (2012).

    Article  Google Scholar 

  132. Haarsma, R. J. et al. High resolution model intercomparison project (HighResMIP v1.0) for CMIP6. Geosci. Model Dev. 9, 4185–4208 (2016).

    Article  Google Scholar 

  133. Siler, N., Proistosescu, C. & Po-Chedley, S. Natural variability has slowed the decline in western U.S. snowpack since the 1980s. Geophys. Res. Lett. 46, 346– 355 (2019).

    Article  Google Scholar 

  134. Hamlet, A. F., Mote, P. W., Clark, M. P. & Lettenmaier, D. P. Twentieth-century trends in runoff, evapotranspiration, and soil moisture in the western United States. J. Clim. 20, 1468–1486 (2007).

    Article  Google Scholar 

  135. Diffenbaugh, N. S., Swain, D. L. & Touma, D. Anthropogenic warming has increased drought risk in California. Proc. Natl Acad. Sci. USA 112, 3931–3936 (2015).

    Article  Google Scholar 

  136. Woodhouse, C. A., Meko, D. M., MacDonald, G. M., Stahle, D. W. & Cook, E. R. A 1,200-year perspective of 21st century drought in southwestern North America. Proc. Natl Acad. Sci. USA 107, 21283–21288 (2010).

    Article  Google Scholar 

  137. Stine, S. Extreme and persistent drought in California and Patagonia during mediaeval time. Nature 369, 546–549 (1994).

    Article  Google Scholar 

  138. Katul, G. G., Oren, R., Manzoni, S., Higgins, C. & Parlange, M. B. Evapotranspiration: a process driving mass transport and energy exchange in the soil-plant-atmosphere-climate system. Rev. Geophys. 50, RG3002 (2012).

    Article  Google Scholar 

  139. Roderick, M. L., Greve, P. & Farquhar, G. D. On the assessment of aridity with changes in atmospheric CO2. Water Resour. Res. 51, 5450–5463 (2015).

    Article  Google Scholar 

  140. Condon, L. E., Atchley, A. L. & Maxwell, R. M. Evapotranspiration depletes groundwater under warming over the contiguous United States. Nat. Commun. 11, 873 (2020).

    Article  Google Scholar 

  141. Jung, M. et al. Recent decline in the global land evapotranspiration trend due to limited moisture supply. Nature 467, 951–954 (2010).

    Article  Google Scholar 

  142. Klos, P. Z. et al. Subsurface plant-accessible water in mountain ecosystems with a Mediterranean climate. Wiley Interdiscip. Rev. Water 5, e1277 (2018).

    Article  Google Scholar 

  143. Goulden, M. L. & Bales, R. C. Vulnerability of montane runoff to increased evapotranspiration with upslope vegetation distribution. Proc. Natl Acad. Sci. USA 111, 14071–14075 (2014).

    Article  Google Scholar 

  144. Tague, C. & Peng, H. The sensitivity of forest water use to the timing of precipitation and snowmelt recharge in the California Sierra: implications for a warming climate. J. Geophys. Res. Biogeosci. 118, 875–887 (2013).

    Article  Google Scholar 

  145. Hayashi, M. Alpine hydrogeology: The critical role of groundwater in sourcing the headwaters of the world. Groundwater 58, 498–510 (2020).

    Article  Google Scholar 

  146. Earman, S., Campbell, A. R., Phillips, F. M. & Newman, B. D. Isotopic exchange between snow and atmospheric water vapor: estimation of the snowmelt component of groundwater recharge in the southwestern United States. J. Geophys. Res. 111, D09302 (2006).

    Google Scholar 

  147. Carroll, R. W. H., Deems, J. S., Niswonger, R., Schumer, R. & Williams, K. H. The importance of interflow to groundwater recharge in a snowmelt‐dominated headwater basin. Geophys. Res. Lett. 46, 5899–5908 (2019).

    Article  Google Scholar 

  148. Winnick, M. J. et al. Snowmelt controls on concentration-discharge relationships and the balance of oxidative and acid-base weathering fluxes in an alpine catchment, East River, Colorado. Water Resour. Res. 53, 2507–2523 (2017).

    Article  Google Scholar 

  149. Dwire, K. A., Mellmann-Brown, S. & Gurrieri, J. T. Potential effects of climate change on riparian areas, wetlands, and groundwater-dependent ecosystems in the Blue Mountains, Oregon, USA. Clim. Serv. 10, 44–52 (2018).

    Article  Google Scholar 

  150. Berghuijs, W. R., Woods, R. A. & Hrachowitz, M. A precipitation shift from snow towards rain leads to a decrease in streamflow. Nat. Clim. Chang. 4, 583–586 (2014).

    Article  Google Scholar 

  151. Davenport, F. V., Herrera‐Estrada, J. E., Burke, M. & Diffenbaugh, N. S. Flood size increases nonlinearly across the western United States in response to lower snow‐precipitation ratios. Water Resour. Res. 56, e2019WR025571 (2020).

    Article  Google Scholar 

  152. Kampf, S. K. & Lefsky, M. A. Transition of dominant peak flow source from snowmelt to rainfall along the Colorado Front Range: historical patterns, trends, and lessons from the 2013 Colorado Front Range floods. Water Resour. Res. 52, 407–422 (2016).

    Article  Google Scholar 

  153. Mallakpour, I., Sadegh, M. & AghaKouchak, A. A new normal for streamflow in California in a warming climate: wetter wet seasons and drier dry seasons. J. Hydrol. 567, 203–211 (2018).

    Article  Google Scholar 

  154. Barnhart, T. B. et al. Snowmelt rate dictates streamflow. Geophys. Res. Lett. 43, 8006–8016 (2016).

    Article  Google Scholar 

  155. Li, D., Lettenmaier, D. P., Margulis, S. A. & Andreadis, K. The role of rain‐on‐snow in flooding over the conterminous United States. Water Resour. Res. 55, 8492–8513 (2019).

    Article  Google Scholar 

  156. Hammond, J. C. & Kampf, S. K. Subannual streamflow responses to rainfall and snowmelt inputs in snow‐dominated watersheds of the western United States. Water Resour. Res. 56, e2019WR026132 (2020).

    Article  Google Scholar 

  157. Godsey, S. E., Kirchner, J. W. & Tague, C. L. Effects of changes in winter snowpacks on summer low flows: case studies in the Sierra Nevada, California, USA. Hydrol. Process. 28, 5048–5064 (2014).

    Article  Google Scholar 

  158. Tague, C. & Grant, G. E. Groundwater dynamics mediate low-flow response to global warming in snow-dominated alpine regions. Water Resour. Res. 45, W07421 (2009).

    Article  Google Scholar 

  159. Safeeq, M., Grant, G. E., Lewis, S. L. & Tague, C. L. Coupling snowpack and groundwater dynamics to interpret historical streamflow trends in the western United States. Hydrol. Process. 27, 655–668 (2013).

    Article  Google Scholar 

  160. Trujillo, E., Molotch, N. P., Goulden, M. L., Kelly, A. E. & Bales, R. C. Elevation-dependent influence of snow accumulation on forest greening. Nat. Geosci. 5, 705–709 (2012).

    Article  Google Scholar 

  161. Hu, J., Moore, D. J. P., Burns, S. P. & Monson, R. K. Longer growing seasons lead to less carbon sequestration by a subalpine forest. Glob. Change Biol. 16, 771–783 (2010).

    Article  Google Scholar 

  162. Thorne, J. H. et al. The impact of climate change uncertainty on California’s vegetation and adaptation management. Ecosphere 8, e02021 (2017).

    Article  Google Scholar 

  163. van Mantgem, P. J. et al. Widespread increase of tree mortality rates in the western United States. Science 323, 521–524 (2009).

    Article  Google Scholar 

  164. Allen, C. D. et al. A global overview of drought and heat-induced tree mortality reveals emerging climate change risks for forests. For. Ecol. Manage. 259, 660–684 (2010).

    Article  Google Scholar 

  165. Littell, J. S., McKenzie, D., Wan, H. Y. & Cushman, S. A. Climate change and future wildfire in the western United States: an ecological approach to nonstationarity. Earths Future 6, 1097–1111 (2018).

    Article  Google Scholar 

  166. Bentz, B. J. et al. Climate change and bark beetles of the western United States and Canada: direct and indirect effects. Bioscience 60, 602–613 (2010).

    Article  Google Scholar 

  167. Burns, S. P. et al. Snow temperature changes within a seasonal snowpack and their relationship to turbulent fluxes of sensible and latent heat. J. Hydrometeorol. 15, 117–142 (2014).

    Article  Google Scholar 

  168. Lundquist, J. D., Dickerson-Lange, S. E., Lutz, J. A. & Cristea, N. C. Lower forest density enhances snow retention in regions with warmer winters: a global framework developed from plot-scale observations and modeling. Water Resour. Res. 49, 6356–6370 (2013).

    Article  Google Scholar 

  169. Westerling, A. L., Hidalgo, H. G., Cayan, D. R. & Swetnam, T. W. Warming and earlier spring increase western US forest wildfire activity. Science 313, 940–943 (2006).

    Article  Google Scholar 

  170. Abatzoglou, J. T. & Williams, A. P. Impact of anthropogenic climate change on wildfire across western US forests. Proc. Natl Acad. Sci. USA 113, 11770–11775 (2016).

    Article  Google Scholar 

  171. Gleason, K. E., Nolin, A. W. & Roth, T. R. Charred forests increase snowmelt: effects of burned woody debris and incoming solar radiation on snow ablation. Geophys. Res. Lett. 40, 4654–4661 (2013).

    Article  Google Scholar 

  172. Staley, D. M. et al. Estimating post-fire debris-flow hazards prior to wildfire using a statistical analysis of historical distributions of fire severity from remote sensing data. Int. J. Wildland Fire 27, 595–608 (2018).

    Article  Google Scholar 

  173. Rengers, F. K. et al. Landslides after wildfire: initiation, magnitude, and mobility. Landslides 17, 2631–2641 (2020).

    Article  Google Scholar 

  174. Abraham, J., Dowling, K. & Florentine, S. Risk of post-fire metal mobilization into surface water resources: a review. Sci. Total Environ. 599–600, 1740–1755 (2017).

    Article  Google Scholar 

  175. Rust, A. J., Hogue, T. S., Saxe, S. & McCray, J. Post-fire water-quality response in the western United States. Int. J. Wildland Fire 27, 203–216 (2018).

    Article  Google Scholar 

  176. Wagenbrenner, J. W. & Robichaud, P. R. Post-fire bedload sediment delivery across spatial scales in the interior western United States. Earth Surf. Process. Landf. 39, 865–876 (2014).

    Article  Google Scholar 

  177. Olsen, W. H., Wagenbrenner, J. W. & Robichaud, P. R. Factors affecting connectivity and sediment yields following wildfire and post‐fire salvage logging in California’s Sierra Nevada. Hydrol. Process. 35, e13984 (2021).

    Article  Google Scholar 

  178. Smith, H. G., Sheridan, G. J., Lane, P. N. J., Nyman, P. & Haydon, S. Wildfire effects on water quality in forest catchments: a review with implications for water supply. J. Hydrol. 396, 170–192 (2011).

    Article  Google Scholar 

  179. Bladon, K. D., Emelko, M. B., Silins, U. & Stone, M. Wildfire and the future of water supply. Environ. Sci. Technol. 48, 8936–8943 (2014).

    Article  Google Scholar 

  180. Rhoades, C. C., Nunes, J. P., Silins, U. & Doerr, S. H. The influence of wildfire on water quality and watershed processes: new insights and remaining challenges. Int. J. Wildland Fire 28, 721–725 (2019).

    Article  Google Scholar 

  181. Maina, F. Z. & Siirila-Woodburn, E. R. Watersheds dynamics following wildfires: nonlinear feedbacks and implications on hydrologic responses. Hydrol. Process. 34, 33–50 (2020).

    Article  Google Scholar 

  182. Hallema, D. W. et al. Regional patterns of postwildfire streamflow response in the Western United States: the importance of scale‐specific connectivity. Hydrol. Process. 31, 2582–2598 (2017).

    Article  Google Scholar 

  183. Hanan, E. J. et al. How climate change and fire exclusion drive wildfire regimes at actionable scales. Environ. Res. Lett. 16, 024051 (2021).

    Article  Google Scholar 

  184. Ho, M. et al. The future role of dams in the United States of America. Water Resour. Res. 53, 982–998 (2017).

    Article  Google Scholar 

  185. Luthy, R. G., Wolfand, J. M. & Bradshaw, J. L. Urban water revolution: sustainable water futures for California cities. J. Environ. Eng. 146, 04020065 (2020).

    Article  Google Scholar 

  186. Szinai, J. K., Deshmukh, R., Kammen, D. M. & Jones, A. D. Evaluating cross-sectoral impacts of climate change and adaptations on the energy-water nexus: a framework and California case study. Environ. Res. Lett. 15, 124065 (2020).

    Article  Google Scholar 

  187. Hartman, J., Steele, J., Frazier, S., Montgomery, A. Recommendations for an Effective Water Rights Response to Climate Change (State Water Resources Control Board, 2021).

  188. Mateus, M. C. & Tullos, D. Reliability, sensitivity, and vulnerability of reservoir operations under climate change. J. Water Resour. Plan. Manag. 143, 04016085 (2017).

    Article  Google Scholar 

  189. The Metropolitan Water District of Southern California. Our foundation: securing our imported supplies. mwdh2o http://www.mwdh2o.com/planning-for-tomorrow/securing-our-imported-supplies (2021).

  190. Elias, E. et al. Climate change, agriculture and water resources in the Southwestern United States. J. Contemp. Water Res. Educ. 158, 46–61 (2016).

    Article  Google Scholar 

  191. Hayhoe, K. et al. Emissions pathways, climate change, and impacts on California. Proc. Natl Acad. Sci. USA 101, 12422–12427 (2004).

    Article  Google Scholar 

  192. Balazs, C., Morello-Frosch, R., Hubbard, A. & Ray, I. Social disparities in nitrate-contaminated drinking water in California’s San Joaquin Valley. Environ. Health Perspect. 119, 1272–1278 (2011).

    Article  Google Scholar 

  193. Gautam, M. R., Chief, K. & Smith, W. J. in Climate Change and Indigenous Peoples in the United States: Impacts, Experiences and Actions (eds Maldonado, J. K., Colombi, B. & Pandya, R.) 77–91 (Springer, 2014).

  194. Doyle, J. T., Redsteer, M. H. & Eggers, M. J. Exploring effects of climate change on Northern Plains American Indian health. Clim. Change 120, 643–655 (2013).

    Article  Google Scholar 

  195. Madani, K., Guégan, M. & Uvo, C. B. Climate change impacts on high-elevation hydroelectricity in California. J. Hydrol. 510, 153–163 (2014).

    Article  Google Scholar 

  196. Vicuña, S., Dracup, J. A. & Dale, L. Climate change impacts on two high-elevation hydropower systems in California. Clim. Change 109, 151–169 (2011).

    Article  Google Scholar 

  197. Bartos, M. & Chester, M. Impacts of climate change on electric power supply in the Western United States. Nat. Clim. Chang. 5, 748–752 (2015).

    Article  Google Scholar 

  198. Averyt, K. et al. Sectoral contributions to surface water stress in the coterminous United States. Environ. Res. Lett. 8, 035046 (2013).

    Article  Google Scholar 

  199. Gleick, P. H. Water management: soft water paths. Nature 418, 373 (2002).

    Article  Google Scholar 

  200. Kaatz, L., Raucher, K. & Raucher, R. Embracing uncertainty: a case study examination of how climate change is shifting water utility planning (Stratus Consulting & Denver Water, 2015).

  201. California Water Commission. Water storage investment program technical review: sites reservoir project. CWC https://cwc.ca.gov/Water-Storage/WSIP-Project-Review-Portal/All-Projects/Sites-Project (2018).

  202. Hydro Review Content Directors. Reclamation accepting public comments on proposal to raise height of Shasta Dam. Hydro Review https://www.hydroreview.com/dams-and-civil-structures/reclamation-accepting-public-comments-on-proposal-to-raise-height-of-shasta-dam/ (2020).

  203. Perry, D. M. & Praskievicz, S. J. A new era of big infrastructure? (Re)developing water storage in the U.S. west in the context of climate change and environmental regulation. Water Altern. 10, 437–454 (2017).

    Google Scholar 

  204. James, I. Utah’s proposal to build Colorado River pipeline gets pushback from 6 states. Arizona Republic https://www.azcentral.com/story/news/local/arizona-environment/2020/09/09/arizona-among-6-states-bucking-utahs-lake-powell-pipeline-proposal/5759035002/ (2020).

  205. Ligon, F. K., Dietrich, W. E. & Trush, W. J. Downstream ecological effects of dams: a geomorphic perspective. Bioscience 45, 183–192 (1995).

    Article  Google Scholar 

  206. Liermann, C. R., Nilsson, C., Robertson, J. & Ng, R. Y. Implications of dam obstruction for global freshwater fish diversity. Bioscience 62, 539–548 (2012).

    Article  Google Scholar 

  207. Minear, J. T. & Kondolf, G. M. Estimating reservoir sedimentation rates at large spatial and temporal scales: a case study of California. Water Resour. Res. 45, W12502 (2009).

    Article  Google Scholar 

  208. Smith, R., Kasprzyk, J. R., Basdekas, L. & Dilling, L. Producing regionally-relevant multiobjective tradeoffs to engage with Colorado water managers [abstract H54F-08] (American Geophysical Union, 2016).

  209. Smith, R., Kasprzyk, J. & Dilling, L. Participatory Framework for Assessment and Improvement of Tools (ParFAIT): increasing the impact and relevance of water management decision support research. Environ. Model. Softw. 95, 432–446 (2017).

    Article  Google Scholar 

  210. Sumargo, E., Cannon, F., Ralph, F. M. & Henn, B. Freezing level forecast error can consume reservoir flood control storage: potentials for Lake Oroville and New Bullards Bar reservoirs in California. Water Resour. Res. 56, e2020WR027072 (2020).

    Article  Google Scholar 

  211. Uccellini, L. W. & Ten Hoeve, J. E. Evolving the National Weather Service to build a weather-ready nation: connecting observations, forecasts, and warnings to decision-makers through impact-based decision support services. Bull. Am. Meteorol. Soc. 100, 1923–1942 (2019).

    Article  Google Scholar 

  212. California Department of Water Resources. 2020 Water resilience portfolio: in response to the Executive Order N-10-19 (California Department of Water Resources, 2020).

  213. Luthy, R. G., Sharvelle, S. & Dillon, P. Urban stormwater to enhance water supply. Environ. Sci. Technol. 53, 5534–5542 (2019).

    Article  Google Scholar 

  214. Scanlon, B. R., Reedy, R. C., Faunt, C. C., Pool, D. & Uhlman, K. Enhancing drought resilience with conjunctive use and managed aquifer recharge in California and Arizona. Environ. Res. Lett. 11, 035013 (2016).

    Article  Google Scholar 

  215. Zhang, X. Conjunctive surface water and groundwater management under climate change. Front. Environ. Sci. 3, 59 (2015).

    Article  Google Scholar 

  216. Harpold, A. A. et al. Increasing the efficacy of forest thinning for snow using high‐resolution modeling: a proof of concept in the Lake Tahoe Basin, California, USA. Ecohydrology 13, e2203 (2020).

    Article  Google Scholar 

  217. Farooqi, T. J. A., Li, X., Yu, Z., Liu, S. & Sun, O. J. Reconciliation of research on forest carbon sequestration and water conservation. J. For. Res. 32, 7–14 (2021).

    Article  Google Scholar 

  218. Nelson, E. et al. Modeling multiple ecosystem services, biodiversity conservation, commodity production, and tradeoffs at landscape scales. Front. Ecol. Environ. 7, 4–11 (2009).

    Article  Google Scholar 

  219. French, J. R. et al. Precipitation formation from orographic cloud seeding. Proc. Natl Acad. Sci. USA 115, 1168–1173 (2018).

    Article  Google Scholar 

  220. Grant, S. B. et al. Taking the ‘waste’ out of ‘wastewater’ for human water security and ecosystem sustainability. Science 337, 681–686 (2012).

    Article  Google Scholar 

  221. Hering, J. G., Waite, T. D., Luthy, R. G., Drewes, J. E. & Sedlak, D. L. A changing framework for urban water systems. Environ. Sci. Technol. 47, 10721–10726 (2013).

    Article  Google Scholar 

  222. Cooley, H., Phurisamban, R. & Gleick, P. The cost of alternative urban water supply and efficiency options in California. Environ. Res. Commun. 1, 042001 (2019).

    Article  Google Scholar 

  223. Rao, P., Kostecki, R., Dale, L. & Gadgil, A. Technology and engineering of the water-energy nexus. Annu. Rev. Environ. Resour. 42, 407–437 (2017).

    Article  Google Scholar 

  224. Jägermeyr, J. et al. Integrated crop water management might sustainably halve the global food gap. Environ. Res. Lett. 11, 025002 (2016).

    Article  Google Scholar 

  225. Mitchell, J. et al. No-tillage and high-residue practices reduce soil water evaporation. Calif. Agric. 66, 55–61 (2012).

    Article  Google Scholar 

  226. Jägermeyr, J. et al. Water savings potentials of irrigation systems: global simulation of processes and linkages. Hydrol. Earth Syst. Sci. 19, 3073–3091 (2015).

    Article  Google Scholar 

  227. Davis, K. F., Seveso, A., Rulli, M. C. & D’Odorico, P. Water savings of crop redistribution in the United States. Water 9, 83 (2017).

    Article  Google Scholar 

  228. Gleick, P. H. et al. Waste Not, Want Not: The Potential for Urban Water Conservation in California (Pacific Institute, 2003).

  229. Schwabe, K., Nemati, M., Landry, C. & Zimmerman, G. Water markets in the Western United States: trends and opportunities. Water 12, 233 (2020).

    Article  Google Scholar 

  230. American Society of Civil Engineers. The Economic Benefits of Investing in Water Infrastructure: How a Failure to Act Would Affect the US Economy Recovery (American Society of Civil Engineers, 2020).

  231. Harou, J. J. et al. Hydro-economic models: concepts, design, applications, and future prospects. J. Hydrol. 375, 627–643 (2009).

    Article  Google Scholar 

  232. Condon, L. E. & Maxwell, R. M. Groundwater-fed irrigation impacts spatially distributed temporal scaling behavior of the natural system: a spatio-temporal framework for understanding water management impacts. Environ. Res. Lett. 9, 034009 (2014).

    Article  Google Scholar 

  233. Lemos, M. C., Kirchhoff, C. J. & Ramprasad, V. Narrowing the climate information usability gap. Nat. Clim. Chang. 2, 789–794 (2012).

    Article  Google Scholar 

  234. McNie, E. C. Reconciling the supply of scientific information with user demands: an analysis of the problem and review of the literature. Environ. Sci. Policy 10, 17–38 (2007).

    Article  Google Scholar 

  235. Dewulf, A., Klenk, N., Wyborn, C. & Lemos, M. C. Usable environmental knowledge from the perspective of decision-making: the logics of consequentiality, appropriateness, and meaningfulness. Curr. Opin. Environ. Sustain. 42, 1–6 (2020).

    Article  Google Scholar 

  236. Flagg, J. A. & Kirchhoff, C. J. Context matters: context-related drivers of and barriers to climate information use. Clim. Risk Manag. 20, 1–10 (2018).

    Article  Google Scholar 

  237. Shi, L. et al. Roadmap towards justice in urban climate adaptation research. Nat. Clim. Chang. 6, 131–137 (2016).

    Article  Google Scholar 

  238. Araos, M. et al. Equity in adaptation: a systematic global review. One Earth https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3782859 (2021).

  239. Anguelovski, I. et al. Equity impacts of urban land use planning for climate adaptation: critical perspectives from the global north and south. J. Plan. Educ. Res. 36, 333–348 (2016).

    Article  Google Scholar 

  240. Hawkins, E., Smith, R. S., Gregory, J. M. & Stainforth, D. A. Irreducible uncertainty in near-term climate projections. Clim. Dyn. 46, 3807–3819 (2016).

    Article  Google Scholar 

  241. Poff, N. L. et al. Sustainable water management under future uncertainty with eco-engineering decision scaling. Nat. Clim. Chang. 6, 25–34 (2016).

    Article  Google Scholar 

  242. Haasnoot, M., Kwakkel, J. H., Walker, W. E. & ter Maat, J. Dynamic adaptive policy pathways: a method for crafting robust decisions for a deeply uncertain world. Glob. Environ. Change 23, 485–498 (2013).

    Article  Google Scholar 

  243. Groves, D. G., Molina-Perez, E., Bloom, E. & Fischbach, J. R. in Decision Making under Deep Uncertainty: From Theory to Practice (eds Marchau, V. A. W. J., Walker, W. E., Bloemen, P. J. T. M. & Popper, S. W.) 135–163 (Springer, 2019).

  244. Groves, D., Fischbach, J., Bloom, E., Knopman, D. & Keefe, R. Adapting to a Changing Colorado River: Making Future Water Deliveries More Reliable Through Robust Management Strategies (RAND Corporation, 2013).

  245. Arnott, J. C., Mach, K. J. & Wong-Parodi, G. Editorial overview: The science of actionable knowledge. Curr. Opin. Environ. Sustain. 42, A1–A5 (2020).

    Article  Google Scholar 

  246. Meadow, A. M. et al. Moving toward the deliberate coproduction of climate science knowledge. Weather Clim. Soc. 7, 179–191 (2015).

    Article  Google Scholar 

  247. Cash, D. W. et al. Knowledge systems for sustainable development. Proc. Natl Acad. Sci. USA 100, 8086–8091 (2003).

    Article  Google Scholar 

  248. Dilling, L. & Lemos, M. C. Creating usable science: opportunities and constraints for climate knowledge use and their implications for science policy. Glob. Environ. Change 21, 680–689 (2011).

    Article  Google Scholar 

  249. Lemos, M. C. et al. To co-produce or not to co-produce. Nat. Sustain. 1, 722–724 (2018).

    Article  Google Scholar 

  250. Cash, D. et al. Salience, credibility, legitimacy and boundaries: linking research, assessment and decision making. SSRN https://doi.org/10.2139/ssrn.372280 (2002).

    Article  Google Scholar 

  251. Cash, D. W., Borck, J. C. & Patt, A. G. Countering the loading-dock approach to linking science and decision making: comparative analysis of El Niño/Southern Oscillation (ENSO) forecasting systems. Sci. Technol. Hum. Values 31, 465–494 (2006).

    Article  Google Scholar 

  252. Goodrich, K. A. et al. Who are boundary spanners and how can we support them in making knowledge more actionable in sustainability fields? Curr. Opin. Environ. Sustain. 42, 45–51 (2020).

    Article  Google Scholar 

  253. Little, R. G. What’s next for a national infrastructure policy: an encore or a requiem? Public Work. Manag. Policy 26, 193–199 (2021).

    Article  Google Scholar 

  254. Averyt, K. Are we successfully adapting science to climate change? Bull. Am. Meteorol. Soc. 91, 723–726 (2010).

    Article  Google Scholar 

  255. Zeng, X., Broxton, P. & Dawson, N. Snowpack change from 1982 to 2016 over conterminous United States. Geophys. Res. Lett. 45, 12,940–12,947 (2018).

    Article  Google Scholar 

  256. Gettelman, A., Morrison, H., Thayer-Calder, K. & Zarzycki, C. M. The impact of rimed ice hydrometeors on global and regional climate. J. Adv. Model. Earth Syst. 11, 1543–1562 (2019).

    Article  Google Scholar 

  257. Rhoades, A. M. et al. Sensitivity of mountain hydroclimate simulations in variable‐resolution CESM to microphysics and horizontal resolution. J. Adv. Model. Earth Syst. 10, 1357–1380 (2018).

    Article  Google Scholar 

  258. van Kampenhout, L. et al. Improving the representation of polar snow and firn in the Community Earth System Model. J. Adv. Model. Earth Syst. 9, 2583–2600 (2017).

    Article  Google Scholar 

  259. Marsh, C. B., Pomeroy, J. W. & Spiteri, R. J. Implications of mountain shading on calculating energy for snowmelt using unstructured triangular meshes. Hydrol. Process. 26, 1767–1778 (2012).

    Article  Google Scholar 

  260. Lapo, K. E., Hinkelman, L. M., Raleigh, M. S. & Lundquist, J. D. Impact of errors in the downwelling irradiances on simulations of snow water equivalent, snow surface temperature, and the snow energy balance. Water Resour. Res. 51, 1649–1670 (2015).

    Article  Google Scholar 

  261. Fan, Y. et al. Hillslope hydrology in global change research and Earth system modeling. Water Resour. Res. 55, 1737–1772 (2019).

    Article  Google Scholar 

  262. Slater, A. G. et al. The representation of snow in land surface schemes: results from PILPS 2(d). J. Hydrometeorol. 2, 7–25 (2001).

    Article  Google Scholar 

  263. Jennings, K. S., Winchell, T. S., Livneh, B. & Molotch, N. P. Spatial variation of the rain–snow temperature threshold across the Northern Hemisphere. Nat. Commun.1148 (2019).

  264. Fatichi, S. et al. Soil structure is an important omission in Earth System Models. Nat. Commun. 11, 522 (2020).

    Article  Google Scholar 

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Acknowledgements

P.S.N and E.R.S.-W. acknowledge support from the Watershed Function Scientific Focus Area funded by the US Department of Energy, Office of Science, Office of Biological and Environmental Research under award no. DE‐AC02‐05CH11231. W.D.C and A.M.R. are supported by the Director, Office of Science, Office of Biological and Environmental Research of the US Department of Energy through the Regional and Global Climate Modeling (RGCM) Program under the Calibrated and Systematic Characterization, Attribution and Detection of Extremes (CASCADE) Scientific Focus Area (award no. DE-AC02-05CH11231). A.D.J., A.M.R. and J.S. are supported by the Office of Science, Office of Biological and Environmental Research, Climate and Environmental Science Division of the US Department of Energy as part of the HyperFACETS Project, A Framework for Improving Analysis and Modeling of Earth System and Intersectoral Dynamics at Regional Scales (award no. DE-SC0016605). D.R.F. is supported by the Director, Office of Science, Office of Biological and Environmental Research of the US Department of Energy under contract no. DE-AC02-05CH11231 as part of their Atmospheric System Research (ASR) Program. C.T. is supported by the National Science Foundation’s Hazard SEES program (award no. 1520847) and the National Science Foundation Critical Zone Observatory Network (award no EAR-2012821). B.J.H. is supported by the Sulo and Aileen Maki Endowment. We thank M. Anderson, S. Hatchett, S. Hubbard, C. Koven and P. Ullrich for insightful conversations and constructive comments. We are grateful to W. Grimshaw, D. Yates and Denver Water for providing GIS data on conveyance, rivers and streamflows. We also thank D. Swantek for graphic design help.

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Author notes

  1. These authors contributed equally: Erica R. Siirila-Woodburn, Alan M. Rhoades.

Authors and Affiliations

  1. Earth and Environmental Sciences Area, Lawrence Berkeley National Laboratory, Berkeley, CA, USA

    Erica R. Siirila-Woodburn, Alan M. Rhoades, Julia Szinai, Peter S. Nico, Daniel R. Feldman, Andrew D. Jones & William D. Collins

  2. Western Regional Climate Center (WRCC), Reno, NV, USA

    Benjamin J. Hatchett

  3. Department of Civil Engineering and Construction Engineering Management, California State University, Long Beach, Long Beach, CA, USA

    Laurie S. Huning

  4. Department of Civil and Environmental Engineering, University of California, Irvine, Irvine, CA, USA

    Laurie S. Huning

  5. Energy and Resources Group, University of California, Berkeley, Berkeley, CA, USA

    Julia Szinai & Andrew D. Jones

  6. Bren School of Environmental Science & Management, University of California, Santa Barbara, Santa Barbara, CA, USA

    Christina Tague

  7. Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA, USA

    William D. Collins

  8. Denver Water, Denver, CO, USA

    Laurna Kaatz

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Contributions

E.R.S.-W. and A.M.R. initiated, led and contributed to all aspects of the Review. B.J.H. and L.S.H. contributed to the section on declining mountain snowpack. B.J.H., L.S.H. and W.D.C. contributed to the section on a low-to-no-snow future. C.T. contributed to the section on hydrological impacts. J.S., A.D.J., P.S.N. and L.K. contributed to the adaptation section. All authors contributed to the display items, the introduction and future directions sections, and participated in discussions, revisions and the final production of the manuscript.

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Correspondence to Erica R. Siirila-Woodburn.

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Nature Reviews Earth & Environment thanks Ben Livneh, Philip Mote and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Siirila-Woodburn, E.R., Rhoades, A.M., Hatchett, B.J. et al. A low-to-no snow future and its impacts on water resources in the western United States. Nat Rev Earth Environ 2, 800–819 (2021). https://doi.org/10.1038/s43017-021-00219-y

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