Summary of Hydrologic Testing, Wellbore-Flow Data, and Expanded Water-Level and Water-Quality Data, 2011–15, Fort Irwin National Training Center, San Bernardino County, California

U.S. Geological Survey (USGS) | October 29th, 2019

In view of the U.S. Army’s historical reliance and plans to increase demands on groundwater to supply its operations at Fort Irwin National Training Center (NTC), Calif

In view of the U.S. Army’s historical reliance and plans to increase demands on groundwater to supply its operations at Fort Irwin National Training Center (NTC), California, coupled with the continuing water-level declines in some developed groundwater basins as a result of pumping, the U.S. Geological Survey (USGS), in cooperation with the U.S. Army, evaluated the water resources, including water quality and potential groundwater supply, of undeveloped basins in the NTC. Previous work in the three developed groundwater basins—Langford, Bicycle, and Irwin—provided information to support water-resources management of those basins. During 2009–12, the USGS installed 41 wells at the NTC; 34 wells were at 14 single- or multiple-well monitoring sites, and 7 wells were long-screen test wells. The majority of the wells were installed in previously undeveloped or minimally developed groundwater basins (Cronise, Red Pass, the Central Corridor area, Superior, Goldstone, and Nelson Basins). During 2012–15, the USGS tested hydrologic properties at 32 wells in 8 basins to help characterize the aquifer system. This report presents data and analyses from core samples; slug tests and single-well aquifer tests; coupled measurements of wellbore flow, water levels, and water-quality constituents; and results from two-dimensional numerical modeling. This information provides a basis for developing and constraining basin-scale hydrogeologic framework and groundwater-flow models to further evaluate water resources in each groundwater basin.Core samples were tested for vertical saturated hydraulic conductivity, physical properties, and particle-size distribution. Vertical saturated hydraulic conductivities of the cores ranged from less than 0.00001 to 18.13 feet per day, and porosities ranged from 0.15 to 0.56. These physical properties and particle-size analyses indicate the high degree of heterogeneity of the hydrogeologic deposits penetrated by the boreholes. Horizontal hydraulic conductivities estimated from slug tests in 22 monitoring wells in 6 basins (Cronise, Central Corridor area, Goldstone, Langford, Bicycle, and Nelson Basins) ranged from less than 0.1 to 40 feet per day. Results of the aquifer tests at six test wells in the Goldstone, Nelson, and Superior Basins indicate hydraulic conductivities ranged from 0.37 to 66 feet per day; associated transmissivity values ranged from 130 to 28,000 feet squared per day. Wellbore-flow data, collected from the six test wells under unpumped and pumped conditions, generally showed downward movement of water. Flow data collected under unpumped conditions indicate groundwater entered the well through the upper part of the screened interval and exited to aquifer zones in the lower part of the screened interval at rates ranging from 1 to 3 gallons per minute. Flow data collected under pumping conditions show increased flow downward in the test wells, indicating higher yields from deeper aquifers. Water levels, measured periodically between 2011 and 2015, remained stable during this period in the majority of the wells measured since 2011, except at two monitoring sites in developed basins (Bicycle and Langford). Vertical hydraulic gradients were generally low throughout the NTC, but ranged from –0.0003 to 0.27 during the summer of 2015. Multiple-well monitoring sites in Bicycle, Central Corridor area, Cronise, Goldstone, Nelson, and Superior Basins, had downward vertical gradients.  Groundwater in wells in Nelson and Superior Basins, and wells BLA5, CCT1, and GOLD2 #2, was characterized as sodium-bicarbonate water, whereas groundwater from the remaining wells in Goldstone Basin was characterized as sodium-chloride water and Cronise Basin, and well LL04 was characterized by sodium-sulfate water. Total dissolved solids (TDS) ranged from 285 to 13,400 milligrams per liter (mg/L) TDS and chloride concentrations ranged from 19 to 1,030 mg/L chloride, with lowest concentrations of each in groundwater from Superior and Nelson Basins and highest concentrations in Cronise Basin. Nitrate plus nitrite as nitrogen ranged from less than 0.040 mg/L in groundwater from Cronise and Goldstone Basins to about 20 mg/L in Nelson Basin. Groundwater from wells in Nelson Basin was isotopically light, whereas groundwater samples from wells CRTH1, CRTH2, and LL04 were isotopically heavier and plotted along an evaporative trend line. No measurable tritium was detected in groundwater from 13 wells sampled in 2015, indicating that groundwater was recharged prior to 1952. Measured carbon-14 (14C) activities in groundwater from four wells sampled in 2015 ranged from about 7.9 to 23.5 percent modern carbon and had apparent (uncorrected) ages of 11,970–20,980 years. Arsenic concentrations were above the maximum contaminant level of 10 micrograms per liter in groundwater from all wells, except those in Goldstone Basin and the two deepest wells in Langford Basin (LL04); likewise, fluoride concentrations were above the California maximum contaminant level of 2 mg/L in groundwater from most wells, except those in Goldstone and Superior Basins, the middle well in Langford Basin, middle and deep wells in two locations in Cronise Basin, and two wells in Nelson Basin. Wellbore flow was simulated for each well by using an integrated-flow analysis tool, AnalyzeHOLE, to evaluate aquifer properties and heterogeneity. Horizontal layers in the model (hydrogeologic units) were defined by lithostratigraphic‐geophysical units, interpreted from lithologic and geophysical logs for each well, and were adjusted during calibration. The saturated hydraulic conductivities derived from the calibrated simulations ranged from less than 0.01 to 60 feet per day in Nelson, Goldstone, and Superior Basins.

Supporting sustainable groundwater management

California Agriculture (UCANR) | March 13th, 2018

Implementation of the 2014 Sustainable Groundwater Management Act is on schedule. The first phase, completed in 2017, created a new layer of local government —

Implementation of the 2014 Sustainable Groundwater Management Act is on schedule. The first phase, completed in 2017, created a new layer of local government — groundwater sustainability agencies. Now, these new agencies must prepare groundwater sustainability plans. These plans will lay out a basic reckoning for every overdrafted basin: without additional water to replace groundwater pumping or to recharge aquifers, there will be less available to produce food, supply homes and businesses, and ensure there is enough water for the environment.

Surface Water-Groundwater Interaction Report, Ventura River Habitat Conservation Plan, Ventura River, California

County of Ventura | February 12th, 2001

ENTRIX, Inc. was contracted by the Cooperating Agencies to perform an analysis of surface water and groundwater hydrology in the Ventura River basin as part of th

ENTRIX, Inc. was contracted by the Cooperating Agencies to perform an analysis of surface water and groundwater hydrology in the Ventura River basin as part of the Habitat Conservation Plan (HCP) for the Ventura River in Ventura County, California. The Cooperating Agencies consist of the County of Ventura, the Ventura County Flood Control District (VCFCD), the City of San Buenaventura, the Casitas Municipal Water District (Casitas), the Meiners Oaks County Water District (MOCWD), the Ojai Valley Sanitary District (OVSD), the Ojai Basin Groundwater Management Agency, the Southern California Water Company (SCWC), the Ventura County Water Agency, and the City of Ojai. These agencies all operate and maintain facilities that may affect sensitive biological resources along the Ventura River. To comply with the Endangered Species Act (ESA), the agencies are developing a HCP in consultation with the National Marine Fisheries Service (NMFS) and U.S. Fish and Wildlife Service (USFWS) to serve as the basis for an Incidental Take Permit. The objectives of the surface water-groundwater interaction evaluation, outlined in The Ventura River Habitat Conservation Plan Technical Approach dated March 30, 2000, are to develop an improved understanding of the hydrologic system dynamics and determine the likelihood of groundwater pumping impacts on surface flows, based on available empirical data. The scope of work involved collecting and evaluating available surface flow and groundwater data and prior analyses of the surface and groundwater system. The focus of the evaluation was on the river reaches where the Cooperating Agencies can affect flow. The availability of concurrent surface flow and groundwater data determined the study period(s) and specific reaches analyzed. The study is focused on the Upper Ventura River and San Antonio Creek basins, and a brief discussion is also included for the Ojai Valley groundwater basin. The data reviewed as part of the evaluation included seasonal changes in groundwater levels and groundwater storage, groundwater flow relationships, and estimated contributions from groundwater to surface water.

Surveillance and Monitoring Program (SAMP) Revised Final Report

Central Valley Salinity Alternatives for Long-Term Sustainability (CV-SALTS) | December 1st, 2016

Among other things, the State Recycled Water Policy (SRWP) requires that development of the Salt and Nitrate Management Plan (SNMP) include the following element (S

Among other things, the State Recycled Water Policy (SRWP) requires that development of the Salt and Nitrate Management Plan (SNMP) include the following element (SRWP Section 6.b.3 (a)): “A basin/sub‐basin wide monitoring plan that includes an appropriate network of monitoring locations. The scale of the basin/subbasin monitoring plan is dependent upon the sitespecific conditions and shall be adequate to provide a reasonable, cost‐effective means of determining whether the concentrations of salt, nutrients, and other constituents of concern as identified in the salt and nutrient plans are consistent with applicable water quality objectives.” Furthermore, “Salts, nutrients, and the constituents identified in paragraph 6(b)(1)(f) shall be monitored. The frequency of monitoring shall be determined in the salt/nutrient management plan and approved by the Regional Water Board pursuant to paragraph 6(b)(2).” This report describes the CV‐SALTS Surveillance and Monitoring Program (SAMP), which was developed to meet the monitoring requirements of the SRWP.

Sustainable Groundwater Management

U.S. Geological Survey (USGS) | February 1st, 2016

According to the [Sustainable Groundwater Management] act, local agencies must develop and implement groundwater-sustainability plans for managing and using groundwater w

According to the [Sustainable Groundwater Management] act, local agencies must develop and implement groundwater-sustainability plans for managing and using groundwater without causing “undesirable results” related to the following: • Groundwater-level declines. • Groundwater-storage reductions. • Seawater intrusion. • Water-quality degradation. • Land subsidence. • Interconnected surface-water depletions. The U.S. Geological Survey (USGS) uses data collection, modeling tools, and scientific analysis to help water managers plan for and assess hydrologic issues that can cause “undesirable results” associated with groundwater use. This information helps managers understand trends and investigate and predict effects of different groundwater management strategies.  

Sustainable Groundwater Management Act (with 2015 amendments)

State of California | January 5th, 2016

Sustainable Groundwater Management Act [And Related Statutory Provisions from SB1168 (Pavley), AB1739 (Dickinson), and SB1319 (Pavley) as Chaptered]

Sustainable Groundwater Management Act [And Related Statutory Provisions from SB1168 (Pavley), AB1739 (Dickinson), and SB1319 (Pavley) as Chaptered]

Sustainable Groundwater Management Act Governance Strategies Summary Report

California State University, Fresno (CSUF) | September 15th, 2021

A three-bill legislative package, referred to as the Sustainable Groundwater Management Act (SGMA), created a fundamental change in the governance of California’s groun

A three-bill legislative package, referred to as the Sustainable Groundwater Management Act (SGMA), created a fundamental change in the governance of California’s groundwater. SGMA requires, with some exceptions, the formation of groundwater sustainability agencies (GSAs) for identified groundwater subbasins. Signed into law in 2014 by Governor Jerry Brown, it set forth a long-term, statewide framework to protect groundwater resources. This report outlines the initial implementation of these new laws by the GSAs in 21 critically overdrafted groundwater subbasins2. Based on a review of multiple statutes, regulations, early research, official government documents and interviews with individuals involved in the process, the authors explain how these first GSAs were created and the organizational and governance challenges they navigated. Once formed, the GSAs were charged with the development and implementation of groundwater sustainability plans (GSPs). The purpose of a GSP is to avoid the undesirable results of groundwater depletion and mitigate overdraft within 20 years. A review of the formation process for this set of GSAs was particularly instructive as they were required to meet a set of SGMA requirements two years earlier than the remaining legislatively identified basins. Presented in an approach that moves from the general to the specific, this report documents the historic process of how 125 GSAs began to implement SGMA. In addition, this report provides important baseline information to help researchers, regulators, policy makers and GSAs themselves, in the development and evaluation of governance and future governance strategies, statutes and regulatory actions. The report is organized into two major topics. 1. Governance structure choices available to GSAs and the GSA formation process set forth in SGMA, including: Specific examples of GSA governance choices. How governance choices were influenced by the preparation and financing of GSPs. 2. Summary findings and observations from interviews of policymakers, technical experts, and thought leaders on their perception of the GSA governance decision-making process and the improvements they believe would benefit SGMA outcomes.The interviewees’ insights reflect the experience they gained during the formation of the critically overdrafted basins GSAs. They identified key elements they felt would be helpful when forming future GSAs, most notably: Providing simplified groundwater science education information for managers, leaders, and groundwaters users. Implementing agency leadership training so the organizational structures and efforts of GSAs can be fully responsive to constituents. Heightening attention relative to some of the beneficial uses of groundwater that were not adequately addressed by GSPs, such as small domestic wells and environmental needs. These experts also observed that implementation of SGMA is an iterative process and that time will be needed to develop, implement, measure, and improve the results of groundwater management strategies. A variety of additional sources of information are offered throughout this report. In addition, Appendix A includes searchable links and information on GSAs, GSPs and other governance elements found in DWR’s (Department of Water Resources) SGMA Portal.

Sustainable Groundwater Management Program Groundwater Sustainability Plan Assessment Staff Report – Big Valley Basin (No. 5-004)

California Department of Water Resources (DWR) | October 26th, 2023

Sustainable Groundwater Management: What We Can Learn from California’s Central Valley Streams

Nature Conservancy | June 13th, 2014

Groundwater is intimately connected to surface water, which has profound implications for sustainable water resource management. California has historically overlooked th

Groundwater is intimately connected to surface water, which has profound implications for sustainable water resource management. California has historically overlooked this important interaction and as a consequence, decisions about groundwater extractions have generally failed to address the resulting impacts to surface flows and aquatic ecosystems such as rivers, wetlands and springs. This has contributed to a loss of approximately 95 percent of the historical wetlands and river habitat in California’s Central Valley. With the passage of the Sustainable Groundwater Management Act (SGMA), groundwater sustainability agencies across the state will soon be required to manage groundwater resources to avoid causing undesirable results to groundwater levels and interconnected groundwater and surface water. These groundwater levels and areas of interconnection support groundwater- dependent ecosystems2 (GDEs). Therefore, an important first step in sustainable groundwater management is to understand how groundwater pumping impacts surface water, including streams, and GDEs.

Sustainable L.A. Grand Challenge Environmental Report Card for Los Angeles County: Water 2019

University of California, Los Angeles (UCLA) | October 22nd, 2019

The Sustainable LA Grand Challenge (SLA GC) Environmental Report Card (ERC) for Los Angeles County (L.A. County) is the only comprehensive environmental report card for

The Sustainable LA Grand Challenge (SLA GC) Environmental Report Card (ERC) for Los Angeles County (L.A. County) is the only comprehensive environmental report card for a megacity in the world. This 2019 ERC on Water provides an in-depth look at the region’s efforts in moving toward a more resilient local water supply, which requires maximizing high quality local water supplies, improving water conveyance and treatment infrastructure, reducing water consumption, and implementing innovative technology and policy solutions. Twenty indicators were assessed across eight categories. Many of these indicators are new areas of assessment for the ERC and will provide a more comprehensive picture of current conditions compared to the 2015 ERC that last assessed L.A. County’s water. Grades were assigned in each category based on compliance with environmental laws or numeric standards where applicable, on our best professional judgment, and on historical improvements and context. This year’s grades range from D/ Incomplete to B+, and although there has been great progress in some areas, others still require significant improvement to raise the county’s C+ average.