The unequal burdens of water scarcity

Nature Portfolio (Springer Nature) | January 19th, 2023

Curtailing water use during drought is costly, but those costs are not evenly distributed. Socio–hydrological modelling shows how water burdens fall more heavily on poo

Curtailing water use during drought is costly, but those costs are not evenly distributed. Socio–hydrological modelling shows how water burdens fall more heavily on poor households in response to water conservation policies.

The Uneven Nature of Daily Precipitation and Its Change

American Geophysical Union (AGU) | October 19th, 2018

Rain falls unevenly in time, which can lead to floods and droughts. It is widely known that precipitation is uneven, but it is difficult to quantify. Here we develop a me

Rain falls unevenly in time, which can lead to floods and droughts. It is widely known that precipitation is uneven, but it is difficult to quantify. Here we develop a measure for the unevenness of precipitation: the number of the wettest days each year in which half of the annual rain falls. We apply this to rain observed by gauges around the world. At all gauges combined, it takes only 12 days each year for half of the rain to fall. We also apply the measure to climate model simulations, with projections for the rest of the century. In the climate model simulations, the change in future rainfall is even more uneven than rainfall today: In a scenario with high greenhouse‐gas emissions, half of the increase in rainfall happens in the wettest 6 days each year. Rather than assuming more rain in general, society needs to take measures to deal with little change most of the time and a handful of events with much more rain.

The Value of Water Supply Reliability in Urban Water Systems

Journal of Environmental Economics and Management (Elsevier) | January 4th, 1994

Reliability is an important dimension of urban water supply. While out-of-pocket losses appear small, water customers place high values on reliability. This demand for re

Reliability is an important dimension of urban water supply. While out-of-pocket losses appear small, water customers place high values on reliability. This demand for reliability can be measured by contingent valuation methods, while the costs of providing various levels of reliability can be estimated through hydrologic simulation. A framework for optimizing reliability is presented and the contingent valuation survey is described. Results from three Colorado towns are presented.

The Water Districts of California

Association of California Water Agencies (ACWA) | April 1st, 1979

The West Wide Drought Tracker: Drought Monitoring at Fine Spatial Scales

American Meteorological Society (AMS) | September 1st, 2017

 The western United States has seen increases in population and water use over the past century. Total water use has remained relatively unchanged over the past several

 The western United States has seen increases in population and water use over the past century. Total water use has remained relatively unchanged over the past several decades due to water conservation efforts. However, water scarcity has become more acute across much of this semiarid region during recent decades due to long-term declines in water storage juxtaposed with the region’s notable hydroclimatic variability. Observed declines in mountain snowpack and increases in atmospheric demands tied to long-term warming trends have further exacerbated water scarcity and increased the importance of monitoring efforts given the array of social, economic, and ecosystem sectors dependent upon the already stressed water supply. The recent severe drought in California and protracted drought across much of the southwestern United States over the past couple decades have prompted demand for accessible drought decision-making information at appropriate spatial scales across the western United States. 

Third Supplement To State Water Resources Board Bulletin No. 11, San Joaquin County Investigation, Basic Data, Calaveras Unit 1956-57

California Department of Water Resources (DWR) | January 21st, 1958

Thirstwaves: Prolonged Periods of Agricultural Exposure to Extreme Atmospheric Evaporative Demand for Water

American Geophysical Union (AGU) | March 20th, 2025

Global atmospheric evaporative demand has increased, impacting agricultural productivity and water use. Traditionally, trend assessments have been limited to total evapor

Global atmospheric evaporative demand has increased, impacting agricultural productivity and water use. Traditionally, trend assessments have been limited to total evaporative demand, overlooking shifts in daily extremes, which are meaningful for agrohydrological outcomes yet largely unknown. Here, using a fully physical metric of evaporative demand, that is, standardized short crop reference evapotranspiration, we introduce the concept of thirstwaves—prolonged periods of extremely high evaporative demand—and analyze their characteristics during 1981–2021 growing seasons for the conterminous US. Findings show that long-term mean spatial patterns demonstrated by thirstwave characteristics do not follow that of total or mean evaporative demand. Weighted for cropland area harvested, thirstwave intensity, duration, and frequency have increased by 0.06 mm d−1 decade−1, 0.10 days decade−1, and 0.39 events decade−1, respectively during 1981–2021. Statistically significant trends appear across 17%, 7%, and 23% of cropland area for intensity, frequency, and duration. Not only have thirstwaves increased in severity, but the likelihood of no thirstwaves occurring during the growing season has significantly decreased. Our work proposes a novel metric to describe periods of extremely elevated evaporative demand and presents a systematic analysis of such conditions historically for US croplands.

Thousands of domestic and public supply wells face failure despite groundwater sustainability reform in California’s Central Valley

Nature Portfolio (Springer Nature) | September 8th, 2023

Total Water Management Study for the Central Valley Basin, California, Central Valley Project Intermittent Surface Water Supply, Working Document No. 6

U.S. Bureau of Reclamation (USBR) | April 1st, 1975

Total Water Management Study for the Central Valley Basin, California, Central Valley Project Water Yield Risk Working Document No. 5

U.S. Bureau of Reclamation (USBR) | February 1st, 1975