South Lahontan

The potential of collaborative solutions to improve management of California (United States) wildlands

Restoration Ecology, Society for Ecological Restoration (SER) | November 13th, 2024

The Public Trust Doctrine and California Water Law: National Audubon Society v. Department of Water and Power

University of California College of the Law, San Francisco (UC Law SF) | June 15th, 1982

Conflicting demands on dwindling surface water supplies in California have led to frequent challenges of state decisions to grant diversions of water that impair or destr

Conflicting demands on dwindling surface water supplies in California have led to frequent challenges of state decisions to grant diversions of water that impair or destroy ecological, recreational, or other instream uses of surface waters. This Comment examines the fundamental problems of surface water allocation in California and addresses the possibility of incorporating the public trust doctrine into the current water law system. The Comment then evaluates a recent attempt to apply the public trust doctrine in National Audubon Society v. Department of Water and Power. The Comment concludes by offering an alternative means to public trust protection of California's surface waters.

The Rainfall Intensity-Duration Control of Debris Flows After Wildfire

American Geophysical Union (AGU) | May 23rd, 2023

The Rebirth of California Fish & Game Code Section 5937: Water for Fish

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

Swarms of living creatures will live wherever the river flows. There will be large numbers of fish, because this water flows there and makes the salt water fresh; so wh

Swarms of living creatures will live wherever the river flows. There will be large numbers of fish, because this water flows there and makes the salt water fresh; so where the river flows everything will live. Fishermen will stand along the shore; from En Gedi to En Eglaim there will be places for spreading nets. In an average year, California receives inflows and imports of water totaling around 200 million acre-feet,2 enough water to cover the entire state twenty-three inches deep. But California is a state of spatial and temporal water extremes. Spatially, precipitation varies wildly: Death Valley in the Southeast averages less than three inches per year, yet the northwestern corner of the state averages over 140 inches per year. More than 70% of California’s stream flow originates north of Sacramento, but more than 80% of the water is used south of Sacramento. Temporally, precipitation varies both seasonally and annually. California’s wet season typically runs from October or November to April or May, with little or no precipitation during the growing season, from May to September.7 Annual rainfalls of 40% or more below average and 36% or more above average each typically occur once every six to seven years.  To balance these extremes, over 1,300 dams store water across the state, supplying water for urban, industrial, and agricultural uses. While these uses sustain a tremendous part of California’s economy, they also come at high, often unappreciated costs. Fish also need water, so dams that alter water flows for human benefits may also have marked negative impacts on fish.

The Relationship between California Rainfall and ENSO Events

American Meteorological Society (AMS) | November 1st, 1989

This paper examines the annual rainfall over California during 11 ENSO events within the period 1950 to 1982. During six of these, unusually wet conditions prevailed thro

This paper examines the annual rainfall over California during 11 ENSO events within the period 1950 to 1982. During six of these, unusually wet conditions prevailed throughout California; conditions were near normal during five events; and in one extreme drought occurred statewide. A comparison with the ENSO classification scheme of Fu et al, based on SST patterns in the Pacific, shows an excellent correspondence. Type 1 years, with large positive temperature anomalies east of the date line and lasting well into winter, are invariably events that enhance California rainfall. Normal years coincide with Type 2 ENSO events (moderate warming over a broad sector); the dry year is the sole Type 3 year, with weak anomalies confined to the eastern Pacific. This study also shows that the response to ENSO is regionally specific. Although throughout the state most years with extremely wet conditions are ENSO years, the tendency for an ENSO event to increase rainfall is greatest in Southern California, where 9 of 11 events produced above-normal rainfall and 8 of the 10 wettest years was an ENSO year. The pattern is more complex in central California; there ENSO years are almost invariably ones with highly abnormal rainfall, but they may be either wet or dry. The areas least influenced by ENSO are the Sierra Nevada and Northern California. The reasons for the geographical pattern of response become apparent when the seasonality and causes of rainfall in the various regions are evaluated.

The relative contributions of summer and cool-season precipitation to groundwater recharge, Spring Mountains, Nevada, USA

Hydrogeology Journal (Springer) | June 1st, 1998

A comparison of the stable-isotope signatures of spring waters, snow, snowmelt, summer (July thru September) rain, and cool season (October thru June) rain indicates that

A comparison of the stable-isotope signatures of spring waters, snow, snowmelt, summer (July thru September) rain, and cool season (October thru June) rain indicates that the high-intensity, short-duration summer convective storms, which contribute approximately a third of the annual precipitation to the Spring Mountains, provide only a small fraction (perhaps 10%) of the recharge to this major upland in southern Nevada, USA. Late spring snowmelt is the principal means of recharging the fractured Paleozoic-age carbonate rocks comprising the central and highest portion of the Spring Mountains. Daily discharge measurements at Peak Spring Canyon Creek during the period 1978–94 show that snowpacks were greatly enhanced during El Niño events.

The Untapped Potential of California’s Urban Water Supply: Water Efficiency, Water Reuse, and Stormwater Capture

Pacific Institute | April 12th, 2022

In this assessment, we quantify the potential for a range of water strategies in urbanized parts of California to both reduce inefficient and wasteful water uses and expa

In this assessment, we quantify the potential for a range of water strategies in urbanized parts of California to both reduce inefficient and wasteful water uses and expand local water supplies. This assessment finds that urban water-use efficiency improvements could reduce statewide urban water use by 2.0 million to 3.1 million acre-feet per year (AFY). The reuse potential of municipal wastewater is 1.8 million to 2.1 million AFY, and the stormwater capture potential is 580,000 AFY in a dry year to as much as 3.0 million AFY in a wet year. Previous assessments have shown that these efficiency and supply options are more cost effective than traditional – and increasingly hard to implement – options to expand supply. Programs to tap this potential would tremendously help solve California’s long-standing water problems.

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. 

Three-dimensional geologic mapping of the Cenozoic basin fill, Amargosa Desert basin, Nevada and California

U.S. Geological Survey (USGS) | July 1st, 2014

Understanding the subsurface geologic framework of the Cenozoic basin fill that underlies the Amargosa Desert in southern Nevada and southeastern California has been impr

Understanding the subsurface geologic framework of the Cenozoic basin fill that underlies the Amargosa Desert in southern Nevada and southeastern California has been improved by using borehole data to construct three-dimensional lithologic and interpreted facies models. Lithologic data from 210 boreholes from a 20-kilometer (km) by 90-km area were reduced to a limited suite of descriptors based on geologic knowledge of the basin and distributed in three-dimensional space using interpolation methods. The resulting lithologic model of the Amargosa Desert basin portrays a complex system of interfingered coarse- to fine-grained alluvium, playa and palustrine deposits, eolian sands, and interbedded volcanic units. Lithologic units could not be represented in the model as a stacked stratigraphic sequence due to the complex interfingering of lithologic units and the absence of available time-stratigraphic markers. Instead, lithologic units were grouped into interpreted genetic classes, such as playa or alluvial fan, to create a three-dimensional model of the interpreted facies data. Three-dimensional facies models computed from these data portray the alluvial infilling of a tectonically formed basin with intermittent internal drainage and localized regional groundwater discharge. The lithologic and interpreted facies models compare favorably to resistivity, aeromagnetic, and geologic map data, lending confidence to the interpretation.