South Lahontan

Advances in Sub-seasonal to Seasonal Prediction Relevant to Water Management in the Western United States

American Meteorological Society (AMS) | July 21st, 2022

Water management in the semi-arid western United States (U.S.) is a challenging endeavor that evolves from year to year based on large-scale atmospheric and oceanic condi

Water management in the semi-arid western United States (U.S.) is a challenging endeavor that evolves from year to year based on large-scale atmospheric and oceanic conditions. This region has frequently experienced prolonged periods of drought with substantial socioeconomic impacts; the most recent instance involves California entering its third consecutive drought year. As context for the economic implications of drought, California’s enacted state budget for the Fiscal Year 2021-22 authorizes more than $600 million for the California Department of Water Resources for providing immediate drought support to local water agencies (CA State Budget 2021a); this amount is part of a package of more than $5 billion over four years for water resilience and drought preparedness (CA State Budget 2021b). For drought preparedness, state and local water managers would like to rely on skillful forecasts on timescales that span the spectrum between weather forecasts and climate predictions. Despite recent improvements in developing sub-seasonal (2- to 6-weeks lead) and seasonal (2- to 6-months lead) prediction systems that compete with and/or outperform existing dynamical and statistical models (e.g., Gibson et al. 2021, Switanek et al. 2020, DeFlorio et al. 2019), forecasting limitations have hindered crucial management decisions for western U.S. water managers, especially related to longer-lead planning, budgeting, resource allocation, and better preparedness for wet and dry extremes (DeFlorio et al. 2021). Improved understanding of physical phenomena and processes governing weather and climate extremes and utilization of emerging forecast methodologies are critical to developing skillful S2S forecast products relevant to water management.

Advancing Strategic Land Repurposing and Groundwater Sustainability in California

Environmental Defense Fund (EDF) | March 26th, 2021

For decades, California has been on a steady trajectory toward water scarcity, which is now exacerbated by climate change. More frequent and intense droughts and incre

For decades, California has been on a steady trajectory toward water scarcity, which is now exacerbated by climate change. More frequent and intense droughts and increased demands have affected the reliability of surface water supplies. As a result, many have looked to groundwater to fill the gap. Groundwater overpumping has resulted in adverse impacts such as reduction in groundwater storage, subsidence, water quality degradation, sea water intrusion, wells going dry and depletion of interconnected surface waters throughout many areas in California’s San Joaquin Valley. These impacts led to the passage of the Sustainable Groundwater Management Act (SGMA) by the state Legislature in 2014, which mandates sustainable use of groundwater by 2040 for the most critically overdrafted basins.

Agricultural Land Use in California

Public Policy Institute of California (PPIC) | June 25th, 2024

Agricultural risks from changing snowmelt

Nature Portfolio (Springer Nature) | April 20th, 2020

Snowpack stores cold-season precipitation to meet warm-season water demand. Climate change threatens to disturb this balance by altering the fraction of precipita

Snowpack stores cold-season precipitation to meet warm-season water demand. Climate change threatens to disturb this balance by altering the fraction of precipitation falling as snow and the timing of snowmelt, which may have profound effects on food production in basins where irrigated agriculture relies heavily on snowmelt runoff. Here, we analyse global patterns of snowmelt and agricultural water uses to identify regions and crops that are most dependent on snowmelt water resources. We find hotspots primarily in high-mountain Asia (the Tibetan Plateau), Central Asia, western Russia, western US and the southern Andes. Using projections of sub-annual runoff under warming scenarios, we identify the basins most at risk from changing snowmelt patterns, where up to 40% of irrigation demand must be met by new alternative water supplies under a 4 °C warming scenario. Our results highlight basins and crops where adaptation of water management and agricultural systems may be especially critical in a changing climate.

Amargosa Desert Hydrographic Basin 14-230 Groundwater Pumpage Inventory Water Year 2015

State of Nevada | July 31st, 2015

An Estimated Potentiometric Surface of the Death Valley Region, Nevada and California, Developed Using Geographic Information System and Automated Interpolation Techniques

U.S. Geological Survey (USGS) | July 1st, 1998

An Evaluation of California’s Adjudicated Groundwater Basins

University of California, Santa Cruz (UC Santa Cruz) | October 1st, 2016

Groundwater is a critical resource in California, providing on average 30 percent of the state’s total water supply and significantly more during dry years. Many commu

Groundwater is a critical resource in California, providing on average 30 percent of the state’s total water supply and significantly more during dry years. Many communities rely exclusively on groundwater, and it is an essential back-up source of water during droughts when pumping increases significantly to compensate for reduced surface supplies. Local groundwater management agencies, special act districts, and court adjudications are the primary institutional arrangements to manage groundwater in California. Increasing groundwater declines in many areas of the state and concomitant negative impacts prompted the passage of the 2014 Sustainable Groundwater Management Act (SGMA). The SGMA established new requirements for 127 high- and medium-priority groundwater basins that are either in overdraft or vulnerable to overdraft to develop sustainable management programs with increased state oversight. The SGMA defines sustainable groundwater management as: “The management and use of groundwater in a manner that can be maintained during the planning and implementation horizon without causing undesirable results.” Undesirable results include: chronic lowering of groundwater levels; significant and unreasonable reduction of groundwater storage; significant and unreasonable seawater intrusion, degraded water quality, and land subsidence; depletions of interconnected surface water that have significant and unreasonable adverse impacts on beneficial uses of the surface water. The SGMA exempts 388 basins categorized as low- and very-low priority, as well as all the adjudicated groundwater basins and 3 basins with pending groundwater adjudications. The SGMA was followed by the passage of Assembly Bill 1390 (AB 1390) and Senate Bill 226 (SB 226) in 2015 that provide some procedures for groundwater adjudications. In the adjudication of a groundwater basin, the court generally defines and determines water rights for all users and provides court-supervised basin management by a Watermaster, who is usually appointed by the court to ensure that the basin is managed in accordance with the court’s decree. Prior to adjudication, key stakeholders and users of the groundwater in a basin often negotiate a stipulation and physical solution to manage the basin, and the court can then accept it in whole or in part, or reject it and craft a different solution to manage the basin. There is limited analysis of the history and current condition of California’s adjudicated basins and the potential for future improvements to the adjudication process. This report for the State Water Resources Control Board (SWRCB) evaluates all of California’s adjudicated basins with respect to sustainable groundwater management as defined in SGMA including: accomplishments, challenges, how management can be improved, and whether there are common elements that result in the sustainable management of an adjudicated groundwater basin.

An Evolutionary Theory of Administrative Law

Southern Methodist University | May 25th, 2018

Law evolves to accommodate change—this is axiomatic in most academic legal traditions. But in the era of the administrative state, with congressional gridlock and a jud

Law evolves to accommodate change—this is axiomatic in most academic legal traditions. But in the era of the administrative state, with congressional gridlock and a judiciary hesitant to address policy questions, evolution of statutory law has become much more difficult. This leads to pent up demand for change in legal regimes. If the legislature and the courts cannot provide an outlet for this pressure, where does it go? How does the law continue to change? Although other scholars have looked to agencies as engines of legal change, we lack a theoretical framework to understand how that change happens. I argue that an evolutionary framework provides an informative framework for understanding administrative legal change. I provide three case studies that demonstrate the administrative evolution of the Endangered Species Act. In spite of tremendous advances in conservation, fundamental changes in scientists’ understanding of human impacts on the natural world, and increasingly strident clashes over private property rights and endangered species, the Act has remained largely unchanged for the last 35 years. In a functioning legislative system, the Act would have been amended to accommodate many of these changes. Instead, the case studies show a mechanism of legal change through agency action analogous to the mechanisms underlying biological evolution. Other commentators have argued the administrative state stymies evolution of the law, but this research contradicts that view. Applying an evolutionary framework to administrative actions creates a new theory of administrative evolution of the law, placing administrative analysis within the long tradition of evolutionary approaches to legal change used by commentators from Aristotle to Holmes. In contrast to traditional normative theories of administrative law, an evolutionary approach focuses on how change progresses over time. This theory of administrative evolution of the law also casts new light on a host of normative questions, from the role of judicial review to improvements in agency decision-making. Considering administrative actions within the broader context of the legal evolution promises a fruitful new approach to analyzing administrative law.

An Update of the Death Valley Regional Groundwater Flow System Transient Model, Nevada and California

U.S. Geological Survey (USGS) | October 31st, 2016

The U.S. Geological Survey (USGS) has revised the regional-scale Death Valley regional groundwater flow system (DVRFS) numerical model with new data and interpretations s

The U.S. Geological Survey (USGS) has revised the regional-scale Death Valley regional groundwater flow system (DVRFS) numerical model with new data and interpretations since the original numerical flow model was published in 2004 (Belcher (2004); re-published as Belcher and Sweetkind [2010]). Since the original publication of the DVRFS flow model, additional data have been collected and interpretations have been made. Cooperators such as the Bureau of Land Management, National Park Service, U.S. Fish and Wildlife Service, the Department of Energy, and Nye County, Nevada, recognized a need to update the existing regional numerical flow model to maintain its viability as a groundwater management tool for regional stakeholders. For the purposes of this report, the version of the DVRFS numerical flow model documented in Belcher and Sweetkind (2010) and Faunt, Blainey, and others (2010) is designated as DVRFS v. 1.0. The updated version, as presented in this report, is referred to as DVRFS v. 2.0. Knowledge of basin water balances and the magnitude of interbasin groundwater flow is the basis for regional groundwater management and water-resource planning in the Great Basin of Nevada (Scott and others, 1971). Rapid population growth, arid conditions, and increased water use have led to development of available groundwater resources. Groundwater use in some alluvial-fill basins has resulted in continued water-level declines and land subsidence. Adjacent bedrock aquifers are increasingly being targeted for additional development. Such groundwater development may potentially impact local and regional water quantity and quality, existing water rights, and wildlife habitats. An understanding of hydrogeologic processes that control the rate and direction of groundwater flow in southern Nevada is necessary to assess the potential effects of any proposed large-scale groundwater development. Potential water-resource conflicts exist because of disparate interests in the region, particularly with respect to the development of groundwater resources to meet agricultural, municipal, and industrial water demand and the need to protect habitat for endangered and threatened species. Water demands in the Amargosa Farms area from agricultural and suburban development, and rapidly urbanizing areas in Las Vegas and Pahrump Valleys place increasing pressure on existing groundwater resources. In addition, several solar-energy facilities have been proposed within the Death Valley region; water demands for these facilities will vary. Natural groundwater discharge at springs and seeps sustains habitat for numerous species, many of which are threatened, endangered, or otherwise considered sensitive. In 2004, the USGS documented a calibrated numerical flow model of the DVRFS (Belcher, 2004). The model, DVRFS v. 1.0, incorporated elements of several precursor numerical models but defined the boundaries of the regional flow system slightly different than in previous versions. The model simulates transient groundwater flow conditions in the DVRFS from 1913 through 1998. The report was subsequently revised and published as a USGS Professional Paper (Belcher and Sweetkind, 2010). Since release of DVRFS v. 1.0 in 2004, continued use of the model by cooperators, stakeholders, and interested parties in the region has demonstrated the need to improve specific aspects (such as the flow into northern Yucca Flat and parts of the Amargosa Desert), to update it with more recently acquired geologic and hydrologic data, and to extend the simulation period.

Analysis of Potential Water-Supply Management Options, 2010-60, and Documentation of Revisions to the Model of the Irwin Basin Aquifer System, Fort Irwin National Training Center, California

U.S. Geological Survey (USGS) | October 31st, 2014

The Fort Irwin National Training Center is considering several alternatives to manage their limited water-supply sources in the Irwin Basin. An existing three-dimensional

The Fort Irwin National Training Center is considering several alternatives to manage their limited water-supply sources in the Irwin Basin. An existing three-dimensional, finite-difference groundwater-flow model—the U.S. Geological Survey’s MOD-FLOW—of the aquifer system in the basin was updated and the initial input dataset was supplemented with groundwater withdrawal data for the period 2000–10. The updated model was then used to simulate four combinations, or scenarios, of groundwater withdrawal and recharge over the next 50 years (January 2011 through December 2060). The scenarios included combinations of continuing withdrawals from currently active production wells, supplementing any increases in demand with withdrawals from an inactive production well, reducing withdrawal amounts and rates, and reducing the discharge of treated wastewater to infiltration ponds that provide a recharge source to the underlying aquifer. Results of the simulations indicated that, depending on the scenario implemented, groundwater levels would rise (over the next 50 years) from 40 feet to as much as 65 feet in the northwestern part of the Irwin Basin, and from 5 feet to 10 feet in the southeastern part.