North Lahontan

Energy Down the Drain. The Hidden Costs of California's Water Supply

Natural Resources Defense Council (NRDC) | August 2nd, 2004

California has been through its share of scorching droughts and energy shortages, but many residents of the western United States may not realize the close con- n

California has been through its share of scorching droughts and energy shortages, but many residents of the western United States may not realize the close con- nections between water and power resources. Water utilities use large amounts of energy to treat and deliver water. Even after utilities deliver water, consumers burn more energy to heat, cool, and use the water. The California State Water Project is the largest single user of energy in California. In the process of delivering water from the San Francisco Bay-Delta to Southern California, the project uses 2 to 3 percent of all electricity consumed in the state. The State Water Project burns energy pumping water 2,000 feet over the Tehachapi Mountains—the highest lift of any water system in the world. The amount of energy used to deliver that water to residential customers in Southern California is equivalent to approximately one-third of the total average household electric use in the region. Ninety percent of all electricity used on farms is devoted to pumping groundwater for irrigation.

Enhancements to EcoAtlas’ CRAM analysis tools: Habitat Development Curves and Ecoregional Cumulative Distribution Function plots (CDFs)

San Francisco Estuary Institute (SFEI) | April 5th, 2016

Ensuring the Public Trust

University of California, Davis (UC Davis) | July 1st, 2012

The California Supreme Court's recognition of the public trust doctrine as an integral part of California's water rights system was one of the momentous events in the h

The California Supreme Court's recognition of the public trust doctrine as an integral part of California's water rights system was one of the momentous events in the history of California (if not United States) environmental policy.' The court looked back to the foundational purposes of the public trust to hold that there are limits to the sovereign power to privatize the rights to use the waters of the state, and it looked forward to conclude that prudent development and sustainable use of California's water resources require the state to retain authority to protect the public trust for the benefit of all Californians. The court also defined the public trust as an environmental baseline that both protects the traditional interests of navigation, commerce, and fisheries and embodies the contemporary scientific and popular understanding that there are ecological limits to the diversion and use of water for consumptive purposes. The lessons of National Audubon Society v. Superior Court2 are now a commonplace of water rights law, appearing not just in administrative orders and judicial opinions, but also in standard water rights terms, policy studies, and legislation.

Environmental Justice Program Implementation for Lahontan Region

Lahontan Regional Water Quality Control Board (LRWQCB) | January 30th, 2015

The Lahontan Regional Water Quality Control Board (Lahontan Water Board) reviewed how environmental justice (EJ) is conducted in the region and examined new ways to impro

The Lahontan Regional Water Quality Control Board (Lahontan Water Board) reviewed how environmental justice (EJ) is conducted in the region and examined new ways to improve our efforts to benefit the disadvantaged communities in our region. The challenges faced by disadvantaged communities (DACs) in the Lahontan region are unique and often different than other DACs in more urban regions. This report provides an assessment of existing efforts to help DACs and catalogs EJ concerns. In addition, the report includes recommendations to enhance DACs participation in the regulatory process, expand access to funding and technical assistance, and improve water quality and drinking water.

Escalating Hydrological Extremes and Whiplashes in the Western U.S.: Challenges for Water Management and Frontline Communities

American Geophysical Union (AGU) | May 14th, 2025

Evaluation of the Subseasonal Forecast Skill of Floods Associated with Atmospheric Rivers in Coastal Western U.S. Watersheds

American Meteorological Society (AMS) | May 27th, 2021

Atmospheric rivers (ARs) are responsible for up to 90% of major flood events along the U.S. West Coast. The time scale of subseasonal forecasting (from 2 weeks to 1 month

Atmospheric rivers (ARs) are responsible for up to 90% of major flood events along the U.S. West Coast. The time scale of subseasonal forecasting (from 2 weeks to 1 month) is a critical lead time for proactive mitigation of flood disasters. The NOAA Climate Testbed Subseasonal Experiment (SubX) is a research-to-operations project with almost immediate availability of forecasts. It has produced a reforecast database that facilitates evaluation of flood forecasts at these subseasonal lead times. Here, we examine the SubX-driven forecast skill of AR-related flooding out to 4-week lead using the Distributed Hydrology Soil Vegetation Model (DHSVM), with particular attention to the role of antecedent soil moisture (ASM), which modulates the relationship between meteorological and hydrological forecast skill. We study three watersheds along a transect of the U.S. West Coast: the Chehalis River basin in Washington, the Russian River basin in Northern California, and the Santa Margarita River basin in Southern California. We find that the SubX-driven flood forecast skill drops quickly after week 1, during which there is relatively high deterministic forecast skill. We find some probabilistic forecast skill relative to climatology as well as ensemble streamflow prediction (ESP) in week 2, but minimal skill in weeks 3–4, especially for annual maximum floods, notwithstanding some probabilistic skill for smaller floods in week 3. Using ESP and reverse-ESP experiments to consider the relative influence of ASM and SubX reforecast skill, we find that ASM dominates probabilistic forecast skill only for small flood events at week 1, while SubX reforecast skill dominates for large flood events at all lead times.

Evapotranspiration frequently increases during droughts

Nature Portfolio (Springer Nature) | October 27th, 2022

Changes in evapotranspiration (ET) affect water availability and ecosystem health. Higher evaporative demand during drought acts to increase ET, but droughts also reduce

Changes in evapotranspiration (ET) affect water availability and ecosystem health. Higher evaporative demand during drought acts to increase ET, but droughts also reduce the moisture supply necessary for ET, limiting predictions of even the sign of ET anomalies. Drought-driven increases in ET (ET+drought) are of particular concern because they quickly deplete water resources, causing flash droughts and acute stress on ecosystems. Here, using a water balance approach, we show that ET+drought is globally widespread, occurring in 44.4% of drought months. The sign of ET’s drought response depends most on the magnitude of precipitation and total water storage anomalies, rather than its location. The Coupled Model Intercomparison Project Phase 6 Earth system models underestimate the ET+drought probability by nearly one-half, and more so in drier regions, primarily due to missing representations of soil structure effects on soil evaporation, as well as incorrectly parameterized plant and soil traits. These processes should be prioritized to reduce model uncertainties in the water–energy–food nexus.

Evolution of global snow drought characteristics from 1850 to 2100

Environmental Research Letters (IOP) | June 6th, 2023

Examining the Contribution of the Observed Global Warming Trend to the California Droughts of 2012/13 and 2013/14

American Meteorological Society (AMS) | September 30th, 2014

In this study, we examine the November–February California droughts of 2012/13 and 2013/14. During 2013/14, California had its warmest and third driest rainy se

In this study, we examine the November–February California droughts of 2012/13 and 2013/14. During 2013/14, California had its warmest and third driest rainy season on record (1895–2014), while the 2012/13 season registered as the 45th warmest and 38th driest (Vose et al. 2014). The 2013 January–December calendar year was the driest on record (Water CA 2014). These consecutive below-normal seasons conspired with warm temperatures to reduce California’s snowpack to the second lowest level since 1960, when recording began, with snowpack at 24% of normal (Water CA 2014). Between January 2013 and January 2014, satellite observations documented dramatic snowpack-related land cover change (NASA Earth Observatory 2014): in 2014, the Cascade, Sierra Nevada, and Coastal ranges were almost completely devoid of snow. In February and March of 2014, air temperatures were extremely warm (NOAA NCDC 2014; HPRC 2014), and U.S. Geological Survey (USGS) observations indicated extreme or moderate hydrologic drought (USGS 2014) and high levels of vegetation stress (VegDRI 2014). The state declared a drought emergency (NIDIS 2014). While it is too soon to assess the full impact of the 2012/13 and 2013/14 California droughts, they seem likely to substantially impact the state’s ability to generate hydrologic power, support agriculture, reduce the risk of forest and bush fires, and protect fragile ecosystems (Huffington Post 2014). *Chapter 4, Explaining Extreme Events of 2013 from a Climate Perspective, Bull. Amer. Meteor. Soc., 95 (9)

Executive Order N-10-19

State of California | April 29th, 2019