water budget

Search Results

Browse All Documents

2016 Annual Report of Hydrogeologic Conditions, Water Requirements, Supplies and Disposition Santa Maria Valley Management Area

Add to Downloads

2016 Annual Report of Hydrogeologic Conditions, Water Requirements, Supplies and Disposition Santa Maria Valley Management Area
City of Santa Maria | April 13, 2017...
Summary
This annual report of conditions in the Santa Maria Valley Management Area, for calendar year 2016, has been prepared to meet the reporting conditions...
This annual report of conditions in the Santa Maria Valley Management Area, for calendar year 2016, has been prepared to meet the reporting conditions of the June 30, 2005, Stipulation entered by the Superior Court of the State of California, County of Santa Clara, in the Santa Maria Valley Groundwater Basin litigation. The Stipulation divided the overall Santa Maria Valley Groundwater Basin into three management areas, the largest of which overlies the main Santa Maria Valley (the Santa Maria Valley Management Area, or SMVMA) and is the subject of this report. The other two management areas, the Nipomo Mesa Management Area (NMMA) and the Northern Cities Management Area, are addressed in separate annual reports prepared by others.

The Stipulation, approved and implemented in 2008, specifies that monitoring shall be sufficient to determine groundwater conditions, land and water uses, sources of water supply, and the disposition of all water supplies in the Basin. Annual Reports for the SMVMA are to summarize the results of the monitoring and include an analysis of the relationship between projected water demand and supply. The Stipulation was preserved in the California Court of Appeal (Sixth Appellate District) Decision of November 21, 2012, and in the Superior Court of the State of California (County of Santa Clara) Final Judgment of April 23, 2014. Thus, the Physical Solution criteria for monitoring and managing groundwater in the basin remain.

In accordance with the Stipulation, this report on the SMVMA provides a description of the physical setting and briefly describes previous studies conducted in the groundwater basin, including the long-term monitoring program developed for the SMVMA. As reported herein, the Twitchell Management Authority (TMA) commissioned the preparation of a monitoring program for the SMVMA in 2008, and its complete implementation is expected to provide the data with which to fully assess future conditions. This report describes hydrogeologic conditions in the management area historically and through 2016, including groundwater conditions, Twitchell Reservoir operations, and hydrologic and climatic conditions. As with all previous annual reports (commencing in 2008), the water requirements and supplies for agricultural and municipal uses are accounted, as are the components of water disposition in the SMVMA.

Conclusions drawn regarding water resource conditions are discussed, including any finding of severe water shortage, which is concluded to not be the case through 2016. Finally, recommendations are provided with regard to the intra-basin transfer of water from the SMVMA to the NMMA, possible enhancement of groundwater recharge, expanded assessment of water resource conditions, and continued implementation of the monitoring program for the SMVMA.

Janny Choi from Stanford University's Water in the West discusses the Santa Maria stipulation in the 2014 paper Before the Well Runs Dry: Improving the Linkage Between Groundwater and Land Use Planning.

View Document
Become a member to access this feature
Download NowEmail Details
A New Approach to Accounting for Environmental Water Insights from the Sacramento–San Joaquin Delta
$0.00
Add to Downloads

A New Approach to Accounting for Environmental Water Insights from the Sacramento–San Joaquin Delta
Public Policy Institute of California (PPIC) | November 9, 2017...
Summary
How water is apportioned to California’s cities, farms, and the environment can lead to conflict and competition in times of drought. Allocation of...
How water is apportioned to California’s cities, farms, and the environment can lead to conflict and competition in times of drought. Allocation of water to the environment in particular is poorly accounted for and poorly understood—shortcomings that can affect water policy, decision making, and public perception. This report reviews the state’s long-standing methods for defining and accounting for environmental water and proposes reforms to improve the timeliness, transparency, and detail in the accounting of environmental water allocation.

View Document
Become a member to access this feature
Download NowEmail Details
Accounting for California’s Water
$0.00
Add to Downloads

Accounting for California’s Water
Public Policy Institute of California (PPIC) | July 13, 2016...
Summary
Understanding California’s water balance sheet—how much there is, who has claims to it, and what is actually being “spent”—is key to effectively managing...
Understanding California’s water balance sheet—how much there is, who has claims to it, and what is actually being “spent”—is key to effectively managing the state’s limited water supply in support of a healthy economy and environment. The latest drought has spotlighted serious gaps and fragmentation in California’s water accounting system.

In this report, we identify gaps in California’s water information systems. We recommend that the state adopt an overarching goal of modernizing its water accounting, and that key state agencies—supported by an oversight committee of key stakeholders and independent experts—develop and adopt a common accounting framework. We outline a dozen priority actions to strengthen water accounting by: improving measurements and estimates of water availability and use; firming up legal claims on water rights and water reserved for the environment; establishing protocols, standards, and models for transparent water accounting at all levels across the state; and making water information more available and accessible to water managers, water users, policymakers, and the public.

View Document
Become a member to access this feature
Download NowEmail Details
Considering Water Use Efficiency for the Environmental Sector
$0.00
Add to Downloads

Considering Water Use Efficiency for the Environmental Sector
California Department of Water Resources (DWR) | April 29, 2010...
Summary
The goal of this report is to provide a starting point from which the water planning community can move toward improving the allocation...
The goal of this report is to provide a starting point from which the water planning community can move toward improving the allocation of water within the environmental sector. To facilitate that process, this report presents:

1. A discussion that highlights the water community’s points of agreement on the concept of analyzing the application of water to the environment
2. A term, Managed Environmental Water Use Efficiency (MEWUE), to reflect that concept, and a definition of that term
3. A survey of existing methods that could be used to develop MEWUE
4. Suggestions about how to proceed with implementing MEWUE

Based on our analysis, we found that there was genuine interest in understanding and improving how water is allocated to the environment. The idea of maximizing environmental benefits for a given amount of allocated water is a unifying thread among stakeholder interests. We focus on this idea throughout the report as the central concept that MEWUE is intended to achieve.

We propose a new term to reflect the stated concerns of stakeholders that other terms, Environmental Water Use Efficiency and Ecosystem Restoration Water Use Efficiency, did not fully address. We propose Managed to indicate that MEWUE does not evaluate the environment’s use of water per se but rather the effectiveness of water in controlled systems.

We propose Environmental to reflect the range of “uses” of water in the ecosystem, including ecosystem maintenance, restoration, and water quality. Lastly, we support the use of the word Efficiency because efficiency communicates the intent of maximizing benefit for a given amount of water, providing a basis for comparison of the benefits obtainable from different uses of that water.

MEWUE: a mechanism to analyze alternative uses of managed environmental water to determine which allocation of a given amount of water will maximize environmental benefits, and a means to improve decision-making over time.

We address the issue of why having an explicit decision-making mechanism is essential. It is hard to allay the fears that some have of incorrectly measuring environmental benefits. However, it is even more difficult to claim that decisions based on implicit measures and beliefs are better for the environment than those based on some imperfect but explicit consideration of environmental benefits.

View Document
Become a member to access this feature
Download NowEmail Details
Geohydrology and Simulated Response to Ground-Water Pumpage in Carson Valley, A River-Dominated Basin in Douglas County, Nevada, and Alpine County, California
$0.00
Add to Downloads

Geohydrology and Simulated Response to Ground-Water Pumpage in Carson Valley, A River-Dominated Basin in Douglas County, Nevada, and Alpine County, California
U.S. Geological Survey (USGS) | May 2, 1986...
Summary
This investigation of the ground-water hydrology in Carson Valley was conducted from 1980 through 1985 by the U.S. Geological Survey, in cooperation with...
This investigation of the ground-water hydrology in Carson Valley was conducted from 1980 through 1985 by the U.S. Geological Survey, in cooperation with Douglas County. The purpose of the study was to:

(1) collect, compile, and analyze hydrologic data to quantify the hydrology of the valley and to enhance the understanding of the valley's geohydrologic system; and

(2) develop a ground-water model that would simulate the response of the hydrologic system to applied stresses and that could be used to estimate the probable hydrologic effects of various development alternatives.

This report presents the results of the investigation.

Work began with a gravity survey in 1980 to determine the depth to bedrock in Carson Valley; the results are discussed in detail in a separate publication (Maurer, 1986). From 1981 to 1983, work included:

(1) measurement of water-level fluctuations and surface-water runoff,

(2) drilling of additional observation wells,

(3) collection of ground-water pumpage data and measurement of pump efficiencies, and

(4) compilation of existing data reports and drillers 1 logs to obtain estimates of geohydrologic characteristics of the ground-water reservoir.

Development of a water budget and initial estimates of hydraulic conductivities and specific yield were accomplished in 1983. From 1983 to 1985, the ground-water model was developed and calibrated, and simulations of possible ground-water development were made. The model, which represents a compilation of all available data, was used to

(1) test estimates of the geohydrologic characteristics of the ground-water reservoir,

(2) evaluate the components of the water budget for the basin,

(3) enhance the understanding of the hydrologic flow system in the basin, and

(4) simulate the effect of various possible developmental alternatives on Carson River outflow, evapotranspiration, ground-water levels, and ground-water storage in the valley.

View Document
Become a member to access this feature
Download NowEmail Details
Groundwater Availability of the Central Valley Aquifer
$0.00
Add to Downloads

Groundwater Availability of the Central Valley Aquifer
U.S. Geological Survey (USGS) | July 15, 2009...
Summary
California’s Central Valley covers about 20,000 square miles and is one of the most productive agricultural regions in the world. More than 250...
California’s Central Valley covers about 20,000 square miles and is one of the most productive agricultural regions in the world. More than 250 different crops are grown in the Central Valley with an estimated value of $17 billion per year. This irrigated agriculture relies heavily on surface-water diversions and groundwater pumpage. Approximately one-sixth of the Nation’s irrigated land is in the Central Valley, and about one-fifth of the Nation’s groundwater demand is supplied from its aquifers.

The Central Valley also is rapidly becoming an important area for California’s expanding urban population. Since 1980, the population of the Central Valley has nearly doubled from 2 million to 3.8 million people. The Census Bureau projects that the Central Valley’s population will increase to 6 million people by 2020. This surge in population has increased the competition for water resources within the Central Valley and statewide, which likely will be exacerbated by anticipated reductions in deliveries of Colorado River water to southern California. In response to this competition for water, a number of water-related issues have gained prominence: conservation of agricultural land, conjunctive use, artificial recharge, hydrologic implications of land-use change, and effects of climate variability.

To provide information to stakeholders addressing these issues, the USGS Groundwater Resources Program made a detailed assessment of groundwater availability of the Central Valley aquifer system, that includes: (1) the present status of groundwater resources; (2) how these resources have changed over time; and (3) tools to assess system responses to stresses from future human uses and climate variability and change.

This effort builds on previous investigations, such as the USGS Central Valley Regional Aquifer System and Analysis (CV-RASA) project and several other groundwater studies in the Valley completed by Federal, State and local agencies at differing scales. The principal product of this new assessment is a tool referred to as the Central Valley Hydrologic Model (CVHM) that accounts for integrated, variable water supply and demand, and simulates surface-water and groundwater-flow across the entire Central Valley system.

The development of the CVHM comprised four major elements: (1) a comprehensive Geographic Information System (GIS) to compile, analyze and visualize data; (2) a texture model to characterize the aquifer system;(3) estimates of water-budget components by numerically modeling the hydrologic system with the Farm Process (FMP); and (4) simulations to assess and quantify hydrologic conditions.

Chapter A: Introduction, Overview of Hydrogeology, and Textural Model of
California’s Central Valley

Chapter B: Groundwater Availability in California’s Central Valley

Chapter C: Numerical Model of the Hydrologic Landscape and Groundwater Flow in California’s Central Valley

Appendix 1: Supplemental Information—Modifications to
Modflow-2000 Packages and Processes

View Document
Become a member to access this feature
Download NowEmail Details
Groundwater Availability of the Central Valley Aquifer, California
$0.00
Add to Downloads

Groundwater Availability of the Central Valley Aquifer, California
U.S. Geological Survey (USGS) | June 2, 2009...
Summary
The purpose of this report is to describe groundwater availability in the Central Valley. The descriptions are derived largely from the study results,...
The purpose of this report is to describe groundwater availability in the Central Valley. The descriptions are derived largely from the study results, including modeling; however, they also utilize the extensive literature on California’s Central Valley.

The report comprises three chapters and an appendix. Chapter A (this chapter) summarizes the study’s purpose and scope and provides an overview of the hydrogeology of the study area. The hydrogeologic description includes the geologic framework and regional groundwater-flow.

Chapter B describes an analysis and assessment of groundwater availability in the Central Valley—the principal focus of this report. Included in Chapter B are descriptions of the effects of development on the flow system, groundwater sustainability and management, and monitoring of the groundwater system.

Chapter C documents the development of a three-dimensional (3-D), finite-difference numerical model of the Central Valley regional groundwater-flow system. This model is used to evaluate the groundwater availability described in Chapter B. Relative to the previously developed Central Valley Regional Aquifer System Analysis (CV-RASA) model (Williamson and others, 1989), the current model was extended to incorporate a slightly larger geographic area (fig. A1), has a finer spatial and temporal discretization, uses a more-detailed depiction of subsurface geology, and simulates monthly water budgets for April 1961 through September 2003.

Finally, an appendix documents modifications to MODFLOW-2000 (MF2K) that were required to align the functionality of MF2K with the landscape, hydrologic and geologic architecture of the Central Valley. In support of the assessment of groundwater availability in the Central Valley, the study has three objectives:

1. Develop a better understanding of the 3-D internal architecture of the freshwater-bearing deposits of the Central Valley;

2. Utilize enhanced water-budget analysis techniques to estimate water-budget components (recharge, discharge, storage) for the groundwater flow system in areas dominated by irrigated agriculture; and

3. Quantify the Central Valley’s groundwater-flow system to enable the forecasting of system response to stresses from human and environmental stresses at scales relevant to water-management decisions.

The first objective is achieved through the development of a texture model. This texture model is documented in the “Aquifer Characteristics” section of Chapter A of this report. The second objective is achieved through the development of the “Farm Process” (FMP) as an additional simulation component within MF2K. A U.S. Geological Survey Techniques and Methods report documents the Farm Process (Schmid and others, 2006). The application of the FMP within the context of simulating the irrigated agriculture and as much as possible of the hydrologic cycle in the Central Valley also is documented in Chapter C. The final objective is accomplished using a quantitative numerical modeling tool, referred to in this report as the Central Valley Hydrologic Model (CVHM). CVHM consists of a linked landscape-process and groundwater-flow model that is described in Chapter C. Chapter B describes the application of this model for an analysis of groundwater availability in the Central Valley

View Document
Become a member to access this feature
Download NowEmail Details
Missing Water: The Uses and Flows of Water in the Colorado River Delta Region
$0.00
Add to Downloads

Missing Water: The Uses and Flows of Water in the Colorado River Delta Region
Pacific Institute | September 1, 2001...
Summary
The Pacific Institute for Studies in Development, Environment, and Security is pleased to announce the release of Missing Water: The Uses and Flows of...
The Pacific Institute for Studies in Development, Environment, and Security is pleased to announce the release of Missing Water: The Uses and Flows of Water in the Colorado River Delta Region. This new study describes the fate of the millions of acre-feet of water diverted from the Colorado River at and below Imperial Dam, and the total inflows to and outflows from the Colorado River delta region more generally.

This study uses the classic hydrologic boundaries of the delta region described by Godfrey Sykes in 1937, encompassing some 3,325 square miles (8,611 square kilometers) in the states of Arizona, Baja California, California, and Sonora, including the Imperial, Mexicali, and San Luis valleys, Yuma Project lands, and the lower Coachella Valley. The study period examines the flows and uses of water in the years 1991-1998, divided into Flood and Non-Flood years to reflect the tremendous variability of mainstem Colorado River flows.

Missing Water compiles flow data along the mainstem and along diversions within the delta region, the first time such data has been compiled for the region as a whole. The study also report consumptive uses of water in the agricultural and urban sectors, and estimates such use by the environment. Agricultural use is also reported for the major crops in the region, both by acreage and by water use.

View Document
Become a member to access this feature
Download NowEmail Details
Scott Valley Integrated Hydrologic Model: Data Collection, Analysis, and Water Budget Final Report
$0.00
Add to Downloads

Scott Valley Integrated Hydrologic Model: Data Collection, Analysis, and Water Budget Final Report
University of California at Davis, Center for Watershed Sciences | November 14, 2017...
Summary
The Scott Valley is an agricultural groundwater basin in Northern California, within the Scott River watershed and part of the much larger Klamath...
The Scott Valley is an agricultural groundwater basin in Northern California, within the Scott River watershed and part of the much larger Klamath Basin watershed straddling the California-Oregon border. The Scott River provides important habitat for salmonid fish, including spawning and rearing habitat for coho and fall-run Chinook salmon and steelhead trout. Sufficient flows at adequately low temperatures during summer, for rearing, and fall, for spawning, are critical for healthy fish habitat in the mainstem and tributaries.

This report presents the data assembled and the methods used for data analysis and data modeling to prepare the Scott Valley Integrated Hydrologic Model Version 2, which is currently under development. The report includes precipitation data analysis, streamflow data analysis and modeling, geology and groundwater data review and analysis, evapotranspiration and soils data analysis, and preparation of relevant watershed, land use, topography, and irrigation data.

The data collection and analysis efforts culminate in the development of a spatio-temporally distributed soil water budget model for the Scott Valley. The soil water budget model is used to determine spatially and temporally varying groundwater pumping rates, surface water diversion rates, and groundwater recharge across the groundwater basin. The spatial resolution of the soil water budget model is by individual fields (land use polygons). Temporal discretization is in daily time steps for the period from October 1, 1990 to September 30, 2011. This period includes several dry years, average years, and wet year periods. Methods and results of the soil water budget model are presented in this report.

This report represents the next step toward a better understanding of the interactions between groundwater, surface water, land-use, and agricultural practices with a specific focus on the seasonal impacts of groundwater pumping on streamflow during critical low flow periods.

The work presented here relies on an extensive data collection facilitated by the voluntary and active collaboration of communities, landowners, the Scott River Watershed Council (SRWC), the Siskiyou Resource Conservation District (SRCD), and the Scott Valley Groundwater Advisory Committee (GWAC) which has been appointed by the Board of Supervisors in January 2011, meeting monthly since April 2011 and advising UC Davis on its data collection and modeling efforts.

In the data analysis and during the model development, numerous assumptions have been made as is common in building a conceptual and numerical integrated hydrologic model. Models cannot represent the complexity of the real system, but are an effort to capture salient hydrologic features with sufficient accuracy to develop modeling results that are useful for a better understanding of the watershed dynamics and water balance.

View Document
Become a member to access this feature
Download NowEmail Details
SGMA Best Management Practice: Water Budget
$0.00
Add to Downloads

SGMA Best Management Practice: Water Budget
California Department of Water Resources (DWR) | December 23, 2016...
Summary
The objective of this Best Management Practice (BMP) is to assist the use and development of water budgets. The Department of Water Resources...
The objective of this Best Management Practice (BMP) is to assist the use and development of water budgets. The Department of Water Resources (the Department or DWR) has developed this document as part of the obligation in the Technical Assistance Chapter (Chapter 7) of the Sustainable Groundwater Management Act (SGMA) to support the long-term sustainability of California’s groundwater basins. Information provided in this BMP provides technical assistance to Groundwater Sustainability Agencies (GSAs) and other stakeholders on how to address water budget requirements outlined in the Groundwater Sustainability Plan (GSP) Emergency Regulations (GSP Regulations). This BMP identifies available resources to support development, implementation, and reporting of water budget information.

This BMP includes the following sections:
1. Objective. The objective and brief description of the contents of this BMP.
2. Use and Limitations. A brief description of the use and limitations of this BMP.
3. Water Budget Fundamentals. A description of fundamental water budget concepts.
4. Relationship of Water Budgets to other BMPs. A description of how the water budget BMP relates to other BMPs and how water budget information may be used to support development of other GSP requirements.
5. Technical Assistance. A description of technical assistance to support the development of a water budget, potential sources of information, and relevant datasets that can be used to further define each component.
6. Key Definitions. Definitions relevant for this BMP as provided in the GSP Regulations, Basin Boundary Regulations, SGMA, and DWR Bulletin 118.
7. Related Materials. References and other materials that provide supporting information related to the development of water budget estimates.

View Document
Become a member to access this feature
Download NowEmail Details