University of California

Presentations 2016

Detailed Report by Session Themes : Groundwater Management

Abrishamchi, Ahmad

Presentation Title
Planning for Sustainable Management of Groundwater Resources, Case Study: Nishapur plain in Iran
Institution
Dept. of Civ. Engr.UNESCO Chair in Water & Environ. Mngmt for Sustainable Cities,Sharif Univ.of Tech
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Abstract
Sustainable management of groundwater resources is essential for sustainable agriculture in arid and semiarid regions. Groundwater should be managed to be effective, efficient and robust- balancing changes in demands and supplies over time and space and to ensure that there are no negative long-term irreversible or cumulative impacts on ecosystems. The two important considerations in defining sustainable yield are spatial and time scales. Sustainable yield should be defined on a scale small enough to address important local impacts, but large enough to recognize the ability of aquifer systems to adjust to pumping stress. Sustainable yield must also be defined over a specific time period. Pumping, recharge, and ecological response are all time dependent, changing over varying time scales of days, seasons, and years. So, in order to minimize the adverse impacts, sustainable yield should be defined according to the availability of water in different time scales. In Iran, due to its arid-semiarid climatic condition and limitations of dry farming, groundwater management has an essential role in agriculture as well as drinking water supply. Over the years, the agricultural expansion has resulted in over-exploitation of groundwater resources in almost the whole country. Groundwater depletion has caused many problems such as land subsidence, reduction in base flow of the rivers, destruction of wetlands, increasing the cost of pumping, and salt water intrusion in coastal areas. Studies show that over 90 percent of the groundwater basins in Iran are over-exploited and facing ever increasing depletion. The purpose of this paper is to optimize the spatial and temporal scales of Nishapur plain in Khorasan Province in north east of Iran, in order to maximize sustainable yield and minimize negative impacts of groundwater withdrawal. Uncontrolled withdrawal of groundwater resources threatening social integrity and security of the region evidently shows the importance and necessity of planning for sustainable groundwater use in the region. Planning for sustainable management of groundwater resources is a complex task due to its long-term nature faced with many uncertainties. Considering the conditions of the Nishapur plain, different management scenarios are analyzed using MODFLOW and the concept of “capture” to determine sustainable groundwater discharge as follow: changing crop pattern, increasing irrigation efficiency, and improving water productivity; changing the temporal distribution of water use; wastewater reuse; surface water resources development projects; and controlling GW pumping. Having determined the sustainable aquifer discharge in each scenario, Game Theory is used to determine the optimal groundwater resources allocation to different consumers. To consider the effect of uncertainty and participation of stakeholders in the sustainable management of groundwater resources, Bayesian Belief Network (BBN) is used. Hugin software is used for the development of BBN network structure based on the conceptual model of the study area. Available information and data and the results of the integrated model of water resources and uses provide the input data to the network. The main results of this study are the estimate of the regional groundwater sustainable yield as well as the required time to achieve groundwater sustainability in different scenarios.

Archer, Kelly

Presentation Title
The exportation of agricultural water in California and other arid regions of the US.
Institution
UC Berkeley
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Many of the largest agricultural producers in the United States are located in arid regions that have recently experienced extended droughts. In California, 80% of developed water resources are used in agriculture, but the industry only contributes 2% to the state’s gross domestic product. Much of the water used for irrigation is embedded in food products exported from the state. This study estimates the water exported from California and ten other drought-prone states by combining product-level water consumption and national trade data. This research utilized water footprinting methods to estimate total water use for agriculture production. For California, we derived nine unique product water intensities and used spatial analysis to characterize the water sources being used for agriculture. Expanded water footprinting results showed that California (68 TL/yr), Nebraska (60 TL/yr), and Texas (56 TL/yr) were the largest consumers of water for agriculture in 2012 exporting 26%, 50%, and 28% of this water through products, respectively. Agriculture in these arid regions is heavily reliant on groundwater resources, which are being rapidly exhausted in dry periods, compromising sustained production in future droughts. Agricultural drought resilience in these states could be bolstered through alternative water resources, improving water use efficiency, and sustainable groundwater management.

Bachand, Philip

Presentation Title
The challenges of integrating groundwater in a significant way into California’s water supply portfolio
Institution
Bachand & Associates
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California’s unprecedented drought is very likely sign of California’s water future under climate change: longer drought cycles, less reliable snow pack water supplies, higher temperatures and greater reliance on groundwater. The current drought has accelerated groundwater overdraft throughout the state, increased the cost and value of water for farmers, resulted in farmers moving to high value crops, hardened agricultural water demand despite less reliable water supplies, and perhaps most importantly focused the California public on the looming water challenges in the State. California has begun to take action by passing the Sustainable Groundwater Management Act (SGMA) to protect groundwater resources and by making resources available to address the drought. Nevertheless, in the coming decades California will likely face increased challenges in meeting environmental, urban and agricultural water demand because of a number of factors: climate change will likely increase inter- and intra-annual variability in precipitation and move more precipitation from snow to rain in the Sierra Nevada mountains. Combined with increased temperatures and increased summer crop ET demands these hydro-climatic changes will create greater asynchronicity between water supply and agricultural delivery schedules. These challenges will require a re-imagining and perhaps a re-engineering of California’s water system. One potential tool for addressing this challenge is greater reliance on conjunctive use, leveraging private agricultural acreage throughout the Central valley to capture release flows from reservoirs for storage in groundwater reservoirs. The concept of using agricultural lands to capture excess flood flows has been gaining interest and acceptance in California. Challenges associated with this approach include not only technical challenges associated with developing BMPs, strategies and infrastructure for capturing flood and stormwater flows but also challenges associated with integrating flood capture BMPs with farming BMPs to protect crop yields and agricultural profits at economically sustainable levels and with implementing practices in ways that are legally consistent with State water laws, identified beneficial uses and future groundwater sustainability plans developed to comply with SGMA. These questions being currently addressed under several research efforts discussed here are the foundation for a future in which groundwater becomes a more critical and integrated component of California’s water portfolio.

Boyce, Scott

Presentation Title
New MODFLOW’s One-Water Hydrologic Flow Model and Application to Conjunctive Use of the Rio Grande River and Transboundary Aquifers
Institution
USGS
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The Palomas, Mesilla, and Conejos-Medanos Basins in New Mexico, Texas, and Mexico comprise a geologically and hydrologically complex region. The conjunctive use of surface-water and groundwater takes place under a myriad of legal and operational constraints, including the Rio Grande Compact, an international treaty, and the Bureau of Reclamation’s Rio Grande Project. New demands are being placed on the interconnected water system, even as the region is experiencing an extended drought. To better understand the complex hydrogeologic flow system and support ongoing resource management decisions, the U.S. Geological Survey in cooperation with the Bureau of Reclamation is developing the Rio Grande Transboundary Integrated Hydrologic Model (RGTIHM). This model uses MODFLOW’s One-Water Hydrologic Flow Model (MF-OWHM) to build on previous hydrologic modeling efforts. The RGTIHM model is being developed concurrently with the new release of MF-OWHM to take advantage of new features unique to it.The One-Water Hydrologic Flow Model is a MODFLOW-based integrated hydrologic flow model that is the most complete version, to date, of the MODFLOW family of hydrologic simulators needed for the analysis of a broad range of conjunctive-use issues. MF-OWHM fully links the movement and use of groundwater, surface water, and imported water for consumption by agriculture and natural vegetation on the landscape, and for potable and other uses within a supply-and-demand framework. MF-OWHM is based on the Farm Process for MODFLOW-2005 combined with Local Grid Refinement, Streamflow Routing, Surface-water Routing Process, Seawater Intrusion, Riparian Evapotranspiration, and the Newton-Raphson solver. MF-OWHM also includes linkages for deformation-, flow-, and head-dependent flows; additional observation and parameter options for higher-order calibrations; and redesigned code for facilitation of self-updating models and faster simulation run times. The next version of MF-OWHM, currently under development, will include a new surface-water operations module that simulates dynamic reservoir operations, the conduit flow process for karst aquifers and leaky pipe networks, a new subsidence and aquifer compaction package, and additional features and enhancements to enable more integration and cross communication between traditional MODFLOW packages. By retaining and tracking the water within the hydrosphere, MF-OWHM accounts for “all of the water everywhere and all of the time.” This philosophy provides more confidence in the water accounting by the scientific community and provides the public a foundation needed to address wider classes of problems such as evaluation of conjunctive-use alternatives and sustainability analysis, including potential adaptation and mitigation strategies, and best management practices. Thus this provides a more complete understanding of the conjunctive use of surface-water and groundwater along the transboundary aquifer of the Lower Rio Grande.

Brozovic, Nicholas

Presentation Title
Innovations in Agricultural Groundwater Management: Smart Markets for Transferable Pumping Rights
Institution
Daugherty Water for Food Institute, University of Nebraska
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While no national policy on groundwater use exists in the United States, local groundwater management is emerging across the country in response to concerns and conflicts over declining well yields, land subsidence, and the depletion of hydrologically connected surface waters. Management strategies include well drilling moratoria, pumping restrictions, and restrictions on the expansion of irrigated land. To provide flexibility to groundwater users, local regulatory authorities increasingly have begun to allow the transfer of groundwater rights as a cost-effective management tool. Markets can be a versatile risk management tool, helping agricultural communities to cope with scarcity, to meet goals for sustainability, and to grow resilient local economies. For example, active groundwater rights transfers exist in the High Plains region of the United States. Since most groundwater pumped in the High Plains region is used for irrigation, the transfers of use rights are therefore predominantly between agricultural producers. Yet, several barriers to trade exist: high search costs for interested parties, complicated requirements for regulatory compliance, and reluctance to share sensitive financial information. Additionally, groundwater pumping leads to several kinds of spatial and intertemporal externalities such as stream depletion. Indeed, groundwater management schemes that reallocate water between alternate pumping locations are often explicitly designed to change the distribution and magnitude of pumping externalities. Reallocation may be designed to minimize unwanted impacts on third parties or to encourage trades that reduce the magnitude of externalities.We discuss how “smart” markets can deal with complex biophysical constraints while also encouraging active trading, therefore ensuring local goals for aquifer sustainability while growing local economies. Smart markets address these issues by providing a centralized hub for trading, automating the process of regulatory compliance by only matching buyers and sellers eligible to trade as specified in the regulations, and maintaining anonymous, confidential bidding.

Cehrs, David

Presentation Title
Groundwater Management: Past, Present, and Future in the Upper Kings Basin of the Central Valley, California
Institution
Kings River Conservation District
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The Upper Kings Basin is located in California’s Central Valley. It resides on the east side of the valley floor between the valley axis and the Sierran foothills of Fresno County. It contains some of the most productive agricultural land within California. This basin experienced no long term, groundwater overdraft until 1950 and recovered from the 1924-1934 drought within four years. Post 1950, the basin has experienced a continual groundwater overdraft averaging about 209.6 million m3 (170,000 acre feet(af)) per year. This has been driven by increasing irrigated agricultural lands, conversion of dryland farmed agriculture to permanent cropped, irrigated agriculture, and increasing urban water demand due to population growth. The greatest water table declines occur below agricultural areas with no surface water delivery, relying on groundwater for irrigation, and metropolitan Fresno/Clovis, which until 2007 relied solely on groundwater. The areas within the basin with the least overdraft are beneath irrigation districts with surface water deliveries and use supplementary groundwater during low delivery years.Four years of drought have stressed the groundwater system as surface water availability has declined. Within the basin, the 2015 groundwater overdraft will approach 2.4 billion m3 (1.9 million af) with the dominant groundwater management mode being a “race to the bottom”. The basin has the potential to achieve future sustainability by the use of cyclic groundwater recharge and storage. This will be driven by capture and recharge of Kings River flood flows. During flood years the basin needs to recharge between 246.6 million m3 and 739.8 million m3 (200,000 af to 600,000 af) of flood flow in 90 to 120 days in dedicated groundwater recharge basins, recharge wells, over irrigation of crops, and dormant flooding of crops. Other management tools will include: fallowing of some agricultural land, mainly land with no access to surface water, limits on groundwater only irrigated agriculture to perhaps 7620 m3/hectare (2.5 af/acre) per year, and urban conservation, specifically the limiting of landscaping irrigation. These future management practices will be driven by California’s 2014 Sustainable Groundwater Management Act through at least five Groundwater Sustainablility Agencies (GSA) within the basin. Critical to achieving groundwater sustainability is the ability of each GSA to individually moderate its groundwater use but for all the GSA’s to work together in recharging wet year flood flows for the benefit of the entire basin.

Clausnitzer, Volker

Presentation Title
Balancing of interests in polder dewatering: A starring role for an integrated groundwater-surface water model
Institution
DHI-WASY GmbH
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The Odra river floodplains at the German/Polish border have been dewatered and used for farming since the 18th century. An extensive system of hundreds of drainage ditches, a dike along the Odra river, and numerous pumping stations is used and maintained till date, ensuring to keep groundwater levels low enough for farming. At the same time, the remaining wetlands and pristine riparian forests in the area are valued increasingly from a conservation perspective, energy and maintenance costs become more important, and regarding the downstream flood risk precipitation is to be retained in the area for as long as possible. To facilitate the balancing of interests between the different stakeholders, such as farmers, different government authorities, and conservation groups, a coupled groundwater/surface water model has been set up for one of the polders. The integrated model developed in FEFLOW (groundwater) and MIKE 11 (surface water) considers the surface-water network with all control structures and pumping stations as well as the groundwater system. The model has been calibrated in detail for a transient period. Target groundwater levels have been defined, considering both a spatial and a temporal component. For example, farm land requires a high depth-to-groundwater especially in summer, while for wetlands water levels close to the ground surface during the bird-breeding period (until end of April/early May) are most crucial. The current drainage system operation has been evaluated based on these target groundwater levels, showing large deviations from an ideal situation. On basis of this reference scenario, an optimization of the management of the drainage system has been conducted, with the goals of (2) maximum water retention in the area and (2) matching the target levels as closely as possible. The adjustments to the system included different water levels at weirs, construction of new weirs and removal of existing ones, construction of new and abandoning of existing drainage ditches, modification of ditch-clearance plans and change of pumping station operation.Overall, a scenario could be developed that had the potential to significantly improve the situation. Not all goals, however, could be fulfilled in parallel. In order to use local knowledge as much as possible and to finally achieve a compromise that is acceptable to all different groups, the entire project was accompanied by a comprehensive stakeholder-participation process. Nearly all of the proposed measures have finally been accepted – not the least because the modeling tool, which was trusted by all parties involved, provided nonbiased information about benefits and losses for each party in each of the scenarios discussed.

Ekdahl, Erik

Presentation Title
State Implementation of the Sustainable Groundwater Management Act (SGMA)
Institution
State Water Resources Control Board
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California uses more groundwater annually than any other state in the United States. Yet for over a century, California has not regulated groundwater extractions or required comprehensive groundwater management. The Sustainable Groundwater Management Act (SGMA) was signed into law in September, 2014, marking the first significant groundwater management law enacted in California in more than 100 years. SGMA will result in profound changes in how groundwater is used and managed in California. Local agencies must now define when and how groundwater extractions cause significant and unreasonable undesirable results, where an undesirable result is defined in statute as chronic lowering of groundwater levels, reduction of storage, seawater intrusion, degraded water quality, subsidence, and depletions of interconnected surface water. When local efforts are unsuccessful, SGMA authorizes the State Water Resources Control Board (State Water Board) to directly intervene and develop interim groundwater management strategies. The State Water Board faces numerous challenges in setting up and implementing a groundwater management strategy. The presentation will focus on planning efforts currently underway to prepare the state for intervention, including development of regulations, future data needs, data management, and socio/economic drivers. Specific highlights will include development of a State Water Board database to collect and record groundwater extractions from individual wells, remote sensing capabilities and how remote sensing evapotranspiration data could be used for enforcement, how the State Water Board will develop water budgets and verify water budgets developed at the local level, and how State Water Board actions must comply with existing water rights laws and priorities. Additional topics will focus on how state management will differ from locally-developed plans, with particular focus on metering programs, fees, and mandated pumping reductions. Lastly, challenges to local management and state intervention will drive planning elements and will influence local definitions of sustainability. The presentation will highlight these challenges and discuss how intervention will need to incorporate local values and needs.

Famiglietti, Jay

Presentation Title
Enhancing groundwater management capabilities in California’s Central Valley - generating high-resolution groundwater maps from GRACE and in situ data
Institution
NASA Jet Propulsion Laboratory
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Groundwater is a critical component of the local, regional and global water cycle. It constitutes an important storage of water, often relied upon in times of drought and in arid environments. Sustainable planning and management of groundwater resources requires accurate information about trends in groundwater water levels and quantities. In much of the globe, however, this data is limited. The Gravity Recovery and Climate Experiment (GRACE) has already proven to be a powerful data source for regional groundwater assessments in many areas around the world. However, the applicability of this data product to more localized studies and its utility to water management authorities has been constrained by its limited spatial resolution (~150,000 km2). Researchers have begun to address these shortcomings with data assimilation approaches that integrate GRACE total water storage estimates into complex regional models, producing higher-resolution hydrologic results (~4,000 km2). The present study takes these approaches one step further by developing an empirically-based model capable of downscaling GRACE data to a high-resolution (~16 km2) dataset of groundwater storage changes. The model utilizes an artificial neural network (ANN) to generate a series of maps of groundwater level change over the GRACE time period (2002-present) using GRACE estimates of variations in total water storage and a series of publicly available hydrologic variables. The San Joaquin Valley Groundwater Basin in California’s Central Valley serves as the initial case study. Overall, the present study achieves two main goals: 1) it integrates robust numerical methods from the field of systems analysis with geodesy and hydrology; and most importantly 2) it also represents an important application of GRACE data to a local-scale water management study, illustrating how widely available remote sensing data can be utilized by management authorities.

Gailey, Robert

Presentation Title
Hydro-Economic Analysis for Sustainable Groundwater Management
Institution
UC Davis and R.M. Gailey Consulting Hydrogeologist
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In addition to hydrology, elements critical for the sustainable management of groundwater include aspects of economics, engineering, finance, law and politics. Economic analysis will play a significant role and can be combined with hydrogeologic analysis to create useful management formulations. Important considerations with regard to groundwater are: 1) that it exists as a common-pool resource with open access, 2) the magnitude of pumping and scarcity costs, 3) demands (individual, aggregate and hardening), 4) the potential value of markets in counteracting the negative effects of regulation and 6) pumping taxes. This presentation addresses these points from the perspective of agricultural production and within the general context of California’s Sustainable Groundwater Management Act.

Gamon, Daniel

Presentation Title
Summary of Managed Aquifer Recharge Concepts and Planning Methods
Institution
Kleinfelder Inc
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Managed aquifer recharge (MAR), also known as water banking, consists of water management methods and techniques - using treated or non-treated water - to recharge an aquifer, or water bearing zone of sediments, using either surface or subsurface (i.e., via wells) recharge methods. The stored water is available for use in dry years when surface water supplies may be low. Other possible benefits of a properly managed water bank may include making water available for sale, lease, or exchange with other water users for regional water supply sustainability and/or mutual benefit.Surface recharge systems are more likely to work in situations where soils are permeable from the ground surface to the water table, and where adequate land area is available at reasonable cost to accommodate the recharge facilities. Solids that accumulate at the surface are periodically removed following a series of wet-dry cycles to maintain the long-term infiltration rate. Where low permeability soils are present between ground surface and the water table, or where land availability at reasonable cost is limited, surface recharge may not be viable (Pyne, 2005). It must be realized that a MAR system is an engineered system requiring technical inputs from multiple disciplines. Mechanical and process engineering is just as important as water quality modeling and hydrogeologic conceptual modeling inputs for successful design and operations of MAR technology. MAR technology has evolved and supported projects in California for over 40 years, with several long-running projects still in existence and serving as industry standards. Several examples of these long-running successful projects are the Water Replenishment District of Southern California, Orange County Water District, Kern County facilities, and the Santa Clara Valley Water District operations. These successful projects are presented in this paper as examples of surface water-applied aquifer recharge and groundwater-applied aquifer recharge methods as the mechanisms to deliver, store or bank, and extract applied water using a groundwater system. When developing a MAR project, experience has proven that well-researched and planned projects that have well-defined objectives, a solid conceptual model, and proper levels of pilot testing have the best chance of achieving a successful, long-term operation. A project’s conceptual model should include at a minimum a thorough understanding of the site’s hydrology, hydrogeology, mixing water geochemistry, and engineering geologic factors such as soil mechanics and land surface expressions of aquifer response to inflation or deflation. Other technical issues involve the above-ground water delivery system, and logic control systems that run the designed system, including flow control valve technologies that regulate injection and extraction rates. Plugging or clogging is a reality of any system, but a well-defined and executed asset management program can alleviate the severity and frequency of these realities and protect the asset’s investments.Regulatory issues must be confronted and incorporated into project planning. Historical experience has provided some key lessons learned, which are worth incorporating in pre-project planning and design to ensure successful MAR operations. A well-planned public outreach program that informs and engages the community to be served by the MAR project is necessary to the success of such projects; economic considerations can be part of this effort to show the long-term benefit to the community. Recent legislation in California has moved the State toward a more strict and comprehensive policy regarding groundwater management. These new regulations and laws will have particular impact on groundwater basins that have been defined by the California Department of Water Resources as medium or high priority basins. The legislation, signed into law in 2014, creates a framework for sustainable local groundwater management, and allows local agencies to modify groundwater plans to their regional needs. As more counties and local agencies have to comprehensively manage large multi-jurisdictional groundwater basins, more opportunities for MAR/groundwater banking projects should emerge. These projects will have to be planned, designed, and operated by well-trained, experienced, multi-disciplinary teams of professionals.

Garcia, Kristin

Presentation Title
California’s New Groundwater Management Laws, and Strategies to Avoid Adverse Impacts on Agriculture in Urbanizing Communities
Institution
Jackson, DeMarco, Tidus & Peckenpaugh
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On September 16, 2014, California enacted the first comprehensive program for managing and regulating groundwater extraction and use in its history (AB 1739 (Dickinson), SB 1168 (Pavley) and SB 1319 (Pavley)). The policies and regulations set in motion by the new laws will impact existing and future agricultural wells and land uses throughout the State. This presentation will educate attendees about California’s new sustainable groundwater management policies, and provide practical strategies for agricultural businesses in urbanizing areas to join with their local water district, city and county to focus regulatory efforts on increasing the yield of local groundwater basins, and avoid unintended consequences that could reduce available water supplies and restrict existing and future agricultural production. The presentation will discusses key changes that the new laws set in motion, opportunities for agricultural groundwater users in urbanizing areas to have a voice in how the State and local agencies will implement them, and examples of emerging groundwater governance structures that urbanizing communities would be wise to follow or avoid. Groundwater accounts for about a third of all water used in California in an average year, and more than half in a drought year when surface water supplies are unavailable. Some communities are totally reliant on groundwater. Yet, efforts to allocate and manage groundwater in California have often been reactionary, initiated after groundwater use was already impaired by an existing or imminent overdraft condition or groundwater quality degradation. The new laws establish a State policy requiring all groundwater resources to be managed “sustainably”. They also establish a new Sustainable Groundwater Management Act. The Act gives groundwater sustainability agencies broad authority to regulate the extraction and use of groundwater supplies under their groundwater sustainability plans. Any local public agency having water supply, water management or land use responsibilities within a basin (such as public water suppliers, flood control districts, cities and counties) may elect to be the basin’s groundwater sustainability agency. The Act also allows cities and counties to participate in a groundwater sustainability agency. Their participation could bring broader public perspectives to the planning process and help alleviate the concerns of agricultural landowners, who hold superior overlying water rights, potentially being subjected to the control of municipal water agencies in urbanizing areas that operate wells competing for the same limited groundwater supplies and are primarily concerned with their own customers’ interests. The Act defines sustainable groundwater management to include the use of groundwater. By January 1, 2017, the California Department of Water Resources is to publish Best Management Practices to be included in groundwater sustainability plans. Groundwater sustainability plans are also to specify efficient water management practices. Once the BMPs and efficient water management practices are included in a local groundwater sustainability plan, they can be enforced against groundwater users. The presentation will discuss the importance of including agricultural groundwater users in the local groundwater management process in order to maintain production of food and fiber in urbanizing areas.

Holley, Cameron

Presentation Title
Regulating Water Bore Drillers: Lessons from Australia
Institution
Connected Waters Initiative Research Centre, UNSW Australia
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Abstract

Drillers of water bores are vital but rarely-examined actors in water law and regulation. They carry out drilling, bore construction, and other work on bores on behalf of landholders to supply groundwater for stock, domestic, agricultural/irrigation and town water supply purposes. The quality of drilling practices can have significant impacts on groundwater misuse, wastage and degradation, and the location, size and use of bores can impact on the sustainability of groundwater resources. As such, Australia licenses and regulates their activities to ensure the protection of groundwater resources and the long-term economic production of groundwater.Beyond the need to regulate the drilling industry, drillers themselves play a unique role in providing information to agricultural landholders. Because landholders will typically engage a driller to access groundwater, drillers may be the first points of contact about the landholder’s obligations under water management legislation (e.g. to obtain necessary approvals). This role means that drillers have the potential to be a key party that assist or undermine agricultural water user compliance with their obligations under water management legislation.Given the limited examination of the regulation of drillers to date, and their potential lynchpin role in ensuring landholder compliance, this paper examines and assesses the operation of drilling regulation in New South Wales, Australia. Drawing on approximately 45 interviews with drillers and government officers, it provides insights into the effectiveness of these regulations. Its findings reveal some success, but suggest regulation remains confounded by a lack of inspectoral oversight due to geography, resourcing and driller mobility, and current administrative and training arrangements. The paper canvasses options for addressing these challenges, and argues that more effective regulation requires utilising remote monitoring technology and engaging drillers in the regulatory process through a best practice accreditation approach.

Huntington, Justin

Presentation Title
Towards development of a complete Landsat evapotranspiration and energy balance archive to support agricultural consumptive water use reporting and prediction in the Central Valley, CA
Institution
Desert Research Institute / University of Nevada, Reno
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Mapping evapotranspiration (ET) from agricultural areas in California’s Central Valley is critical for understanding historical consumptive use of surface and groundwater. In addition, long histories of ET maps provide valuable training information for predictive studies of surface and groundwater demands. During times of drought, groundwater is commonly pumped to supplement reduced surface water supplies in the Central Valley. Due to the limited data on historic groundwater pumping, using satellite imagery to map evapotranspiration is an efficient and robust way for estimating agricultural consumptive use and assessing drought impacts. To this end, we have developed and implemented an algorithm for automated calibration of the METRIC remotely sensed surface energy balance model on NASA’s Earth Exchange (NEX) to estimate ET at the field scale. Using automated calibration techniques on the NEX has allowed for the creation of spatially explicit historical ET estimates for the Landsat archive dating from 1984 to the near present. Further, our use of spatial NLDAS and CIMIS weather data, and spatial soil water balance simulations within the NEX METRIC workflow, has helped overcome challenges of time integration between satellite image dates. This historical and near present time archive of agricultural water consumption for the Central Valley will be extremely useful dataset for water use and drought impact reporting, and predictive analyses of groundwater demands.

Illangasekare, Tissa

Presentation Title
Incorporating land-atmospheric-vegetation feedbacks into subsurface models used for agriculture water management.
Institution
Colorado School of Mines
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The need for new technologies and improved management strategies for the efficient agricultural water use and sustainability has become imperative due to increasing demand for food due to global population growth as well as climate change driven stresses. Groundwater is a critical resource in the water-energy-food nexus. The problems and challenges associated with groundwater are not only limited to the semi-arid west but also many parts of the word facing with water shortages. Numerical models of both subsurface flow and transport play a central role in assessing the impacts of over water withdrawal and water quality degradation, developing strategies for efficient use and conservation, and management during droughts. In traditional models used in these applications, only the flow processes in the surface water systems, and the unsaturated and saturated zones are simulated. The conditions that determine the mass and energy fluxes at the land surface are incorporated as external boundary conditions. These types of models where the land-atmospheric interactions are decoupled do not allow for the accurate representation of the feedback processes occuring between the soils, plants and the atmosphere. In agriculture applications, such models should capture the boundary layer interactions with the surface topography that is modified by land preparation, vegetation density and distribution on bare soil surfaces and soil structure affected by macroporosity. This paper discusses the knowledge gaps that need to be filled to develop better conceptual and numerical models. Many challenges exist in developing and validation of such models. First the models need to couple drastically different flow dynamics in the boundary layer and the shallow soil in the unsaturated zone. The models also need to capture simultaneously occurring heat and mass fluxes across interfaces. How to parameterize these coupling processes at different scales associated with the soil heterogeneity, micro-topography of land surface and vegetation distribution is not well understood. Validation of these types of models in the field is not practical due to lack of control of the climate conditions. A validation methodology at the intermediate scale using a unique coupled porous media/climate wind tunnel facility is presented.

Jain, Meha

Presentation Title
The relative influence of groundwater versus surface irrigation sources for agricultural production in India
Institution
Stanford University
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India is a hotspot for food security issues over the upcoming decades, due to increasing population, groundwater depletion, and climate change. Investing in additional irrigation infrastructure may bolster food security, however, the relative influence of different types of irrigation (e.g. groundwater versus canal) on agricultural production remains unclear. We assess the relative impact of groundwater (i.e. dug, shallow, and deep wells) and canal irrigation (i.e. surface lift and flow canals) on winter cropped area and its sensitivity to rainfall across India at the village-scale from 2000 to 2012 using high-resolution cropped area maps produced using a novel algorithm applied to MODIS satellite data. We find that deep well irrigation is both associated with the greatest amount of winter cropped area, and is also the least sensitive to monsoon and winter rainfall variability. However, the effectiveness of deep well irrigation varies across India, with the greatest benefits seen in the regions that are most at risk for losing groundwater as a possible source of irrigation over the upcoming decades (e.g. Northwest India). This work highlights the need to develop ways to use remaining groundwater more efficiently (e.g. drip irrigation, less water-intensive crops) given that canal irrigation is not an adequate substitute for India's groundwater.

Joseph, Trevor

Presentation Title
Building Capacity for Regional Sustainability with SGMA
Institution
CA Dept. of Water Resources
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joseph_trevor2
Abstract
While California has vast infrastructure to store winter flows and deliver water hundreds of miles to where it is needed, the majority of water infrastructure and related investment is at the local and regional level. Over the past decade, the State has provided technical services and over $990 million in financial assistance, matched over 4:1 by local agencies, to implement more than 700 regional multi-benefit projects to improve water sustainability in regions across the State.The prolonged drought, reduction of water supply due to reduced rainfall and snowpack, and compliance with various biological opinions, coupled with increases in permanent crops and increases in urban population, have all taken a toll on regional water supply reliability and sustainability. In many areas, imbalance between water availability and demand has increased groundwater pumping and resulted in overdrafting of groundwater basins. This, in turn, has caused drinking and agricultural water wells to go dry and alarming evidence of subsidence, especially in California’s Central Valley.The most significant piece of legislation was the State’s passage of the Sustainable Groundwater Management Act (SGMA) in 2014. For the first time in history, the State must manage groundwater use in a sustainable manner. The landmark law requires water and land use agencies to come together in governance, and develop plans to manage groundwater – in the context of an overall regional water balance – sustainably. The State will provide financial incentives, technical tools, and enforcement to ensure implementation of the legislation, but the key to success lies with the local agencies and their ability to balance regional supply and demand in a more sustainable fashion.The Governor’s 2014 Action Plan has been instrumental in focusing the State’s water leaders on a common set of goals and priority actions, and it has leveraged general obligation bond revenues with existing agency budgets and other funding sources. But, full implementation of the Action Plan, and related actions like SGMA to improve water sustainability, will require investments above the current baseline budgets of State, federal, tribal, and local governments. Multiple and more stable, funding sources will be needed. A key challenge is overcoming regulatory hurdles, including surface water rights and federal and State environmental regulations. Here again, close cooperation between federal, State and local stakeholders will be required for success.

Kacimov, Anvar

Presentation Title
Control of Topology of Water Fluxes in Arid Agriculture: Amalgamation of Subsurface Irrigation, Managed Aquifer Recharge and Engineered Soil Substrate
Institution
Sultan Qaboos University
Video
Video Not Available
Presentation
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Kacimov2
Abstract
Arid zone agriculture in Oman consumes more than 80% of national fresh water resources and relies on shallow unconfined aquifers with an emerging dependence on sewage treated water of quality different from groundwater. A superjacent coarse-textured vadose zone and top soil host plants’ roots subject to harsh conditions of moisture deficit and heat stress that calls for improvements of the conjunctive water use efficiency. Mitigation of adverse ambient conditions impeding the plant growth and causing secondary salinization of topsoil is proposed by innovative agro-engineering techniques. We present the results of field-, farm- observations and experiments, as well as mathematical modeling of optimal control of descending, ascending and lateral water fluxes (viz., evapotranspiration, infiltration, seepage from/to subsurface emitters/drains, losses/gains from/to a deeper confined aquifer commingled via a leaky layer with the irrigated one, and water uptake by roots). We consider two main scenarios of moistening the root zone: by furrows and linear/point sources (subsurface emitters/ leaky pipes) over the soil substrate designed as a tessellation (double-porous medium with a cascade of silt-sand capillary barriers at the interfaces between blocks and fractures). In the first case, two flow regimes are studied: a) with intensive infiltration and phreatic surface mound commanding the periodic surface channels (typical for crop fields with drainage trenches in Holland) and aquitard transmitting groundwater upward from the subjacent aquifer, and b) with intensive evapotranspiration (typical in Oman) when surface water in furrows commands the phreatic surface trough caused by evapotranspiration and groundwater recharged through a leaky layer. The Emikh-Rybakova and Boussinesq-Cherepanov models and analytical solutions are used for quantification of managed aquifer recharge and recovery by controlling the furrow spacing, accretion to the water table and water level in the furrows. In the second scenario, the emitter depth-intensity and hydraulic properties (saturated hydraulic conductivity and capillarity) of the two porous elements and the tessellation geometry determine the tension-saturated perched flow. J.R.Philip, Kirkham-Brock, and Riesenkampf-Vedernikov models are used for predicting the following: a) how much water is “adsorbed” by blocks for further gradual interception by roots, b) how much is winding through the fractures to the next level of the substrate cascade, and c) how much is eventually percolated to the “natural” subsoil and recharges groundwater. Modeled flow nets, isochrones, isotachs, and lines of equal force acting on saturated soil REV (important for structural stability of the designed heterogeneity) are computed by computer algebra routines. Plant characteristics (biomass, number-size of leafs, roots’ architecture) are found in field experiments for various tessellations and irrigation schedules. Both physical and mathematical models prove the efficiency of the proposed optimization of irrigation water fluxes.Acknowledgements: This work was funded by TRC grant RC/AGR/SWAE/16/01.; by SQU, grant IG/AGR/SWAE/14/02; by USAID-FABRI, grant AID-OAA-TO-11-00049, project code:1001626 – 104; by Russian Foundation for Basic Research, grant No 13-01-00322.References:Al-Maktoumi, A., Al-Ismaily, S., Kacimov, A., Al-Busaidi, H., Al-Saqri, S., Al-Haddabi, M. Soil substrate as a cascade of capillary barriers for conserving water in a desert environment: lessons learned from arid nature. J. Arid Land, 2014, 6(6), 690-703, doi: 10.1007/s40333-014-0068-7.Kacimov A.R., Obnosov Yu.V. An exact analytical solution for steady seepage from a perched aquifer to a low-permeable sublayer: Kirkham-Brock's legacy revisited. Water Resources Research, 2015, v.51, 3093–3107, doi:10.1002/2014WR016304.Kacimov A.R., Obnosov Yu.V. Tension-saturated and unsaturated flows from line sources in subsurface irrigation: Riesenkampf’s and Philip’s solutions revisited. Water Resources Research, 2016 (under review).

Kendall, Anthony

Presentation Title
Quantifying the Impacts of Irrigation Technology Adoption on Water Resources in the High Plains Aquifer
Institution
Michigan State University
Video
Video Not Available
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kendall
Abstract
Producers in key agricultural regions worldwide are contending with increasing demand while simultaneously managing declining water resources. The High Plains Aquifer (HPA) is the largest aquifer system in the United States, and supplied most of the water to irrigate 6 million hectares in 2012. Water levels in the central and southern sections of the aquifer have steadily declined, as groundwater recharge in this semi-arid region is insufficient to meet water demands. Individual irrigators have responded to these declines by moving from less efficient irrigation technologies to those that apply water more precisely. Yet, these newer technologies have also allowed for water to be pumped from lower-yielding wells, thus extending the life of any given well and allowing drawdown to continue. Here we use a dataset of the annual irrigation technology choices from every irrigator in the state of Kansas, located in the Central High Plains. This irrigation data, along with remotely-sensed Leaf Area Index, crop choice, and irrigated area, drives a coupled surface/groundwater simulation created using the Landscape Hydrology Model (LHM) to examine the impacts of changing irrigation technology on the regional water cycle, and water levels in the HPA. This application of a coupled surface and groundwater model with unprecedented detail of input land cover characteristics and irrigation water use offers new insights into water resources of this complex and vast aquifer system. For instance, the model is applied to simulate cases in which no irrigation technology change had occurred, and complete adoption of newer technologies to better understand impacts of management choices on regional water resources, and how technologies may be developed or adopted to help adapt to global change.

Kimmelshue, Joel

Presentation Title
Remotely Sensed Crop Mapping Applications for Water Resource Management and Decision Support
Institution
Land IQ
Video
Video Not Available
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kimmelshoe1
Abstract
Accurate and current information on constantly changing agricultural acreage and distribution of crops is critical for environmental, economic and resource management applications. Land use, resource optimization, and economic models and planning significantly depend on accurate spatial land use data, specifically crop type and change. It is important to understand the impacts of crop type and distribution, crop change, acreage, permanent crop age and associated production practices on resource issues such as water quality, water supply, groundwater depletion/recharge, and economic factors. Conversely, environmental factors, such as climate change and sensitive habitats, increasingly influence how much and where these crops are grown. For these purposes, as well as many others, a current spatial mapping base layer is integral for effective resource analysis and decision-making. Past efforts to categorize and/or spatially map land use (specifically field by field agricultural production) throughout the Central Valley of California has either been:• accurate, but intermittent and not spatially contiguous (e.g. CA Department of Water Resources crop mapping)• frequent and spatially contiguous, but with marginal accuracy (e.g. USDA Crop Data Layer)• spatially contiguous, but lacking in specific crop granularity (e.g. CA Department of Conservation Farmland Mapping)• detailed, but incomplete and not spatial (e.g. grower surveys)As a result, there is currently no highly accurate, spatially contiguous, field scale agricultural land use mapping product. In response to this need, detailed crop mapping has been completed across the state of California. Methods have been developed to accurately and efficiently map field-scale crop coverage with remotely sensing techniques. Field-scale information is important because it accurately characterizes acreage irrigated and it captures variability in crop production within parcels or operations. The result is an accurate spatial database of individual crops throughout the state of California with accuracies exceeding 95%. These data are being used to inform decisions on water resource management, support and greatly refine models, evaluate groundwater recharge suitability, and better assess the role of agriculture in management and sustainability of surface and groundwater resources. These data are also integral to the assessments that will be needed as future Groundwater Sustainability Agencies respond to the Sustainable Groundwater Management Act requirements. Growers, industry, regulators, government agencies, and commodity groups also benefit from applying spatial data for land use change, crop type, location, permanent crop age, and density for management of environmental resources and proximity to sensitive areas of water quality, air quality, disease/pest vectors, etc. Collectively, remotely sensed crop mapping data are valuable for:• Surface & groundwater modeling and assessments of groundwater pumping• Groundwater Recharge Enhancement • Evapotranspiration estimations and models (remotely sensed and conventional)• Permanent crop age determination to further refine water use assessments • Permanent (“hard” water requirements) vs. annual crops and locations• Economic & land use trend analysis• Drought and climate change impact analysis• Fallowing trends and locations• Water use efficiency & water infrastructure planning

Kretsinger Grabert, Vicki

Presentation Title
Napa County Groundwater Resources: A Comprehensive Program to Ensure Sustainability
Institution
Luhdorff & Scalmanini Consulting Engineers
Presentation
Abstract
Groundwater and surface water are highly important natural resources in Napa County. Together, the County and other municipalities, water districts, the agricultural community, commercial and industrial operations, and the general public are stewards of the available water resources. Everyone living and working in Napa County has a stake in protecting the county’s groundwater resources, including groundwater supplies, quality, and associated watersheds and ecosystems. Without sustainable groundwater resources, the character of the County would be significantly different in terms of its economy, communities, rural character, ecology, housing, lifestyles, and especially its worldwide acclaim for its vineyards and wines. Similar to other areas in California, businesses and residents of Napa County face many water-related challenges, including sustaining the availability, reliability, and quality of water supplies; preparedness for resources management during drought conditions; and changes in long-term availability due to climate change. In 2009, Napa County embarked on a comprehensive, multi-faceted groundwater program to develop a sound understanding of groundwater conditions through development of an updated hydrogeologic conceptualization and an expanded groundwater monitoring, including designated facilities to assess surface water/groundwater interaction. The program provides the foundation for future coordinated, integrated water resources planning and dissemination of water resources information. In 2011, the Napa County Board of Supervisors adopted a resolution to establish a Groundwater Resources Advisory Committee (GRAC). The County Board of Supervisors appointed 15 residents to the GRAC, which represented diverse interests, including environmental, agricultural, development, and community interests. The GRAC was created to assist County staff and technical consultants with recommendations, including synthesis of existing information and identification of critical data needs; development and implementation of an ongoing groundwater monitoring program; development of groundwater sustainability objectives; and building community support for these activities and next steps. Monitoring provides the metrics that support the larger goal of sustainability. Key objectives of the Napa County Groundwater Monitoring Plan (2013) include addressing data gaps, regular evaluation of groundwater level and/or quality and surface water level and quality trends and factors that warrant further examination to ensure sustainable water resources, and public dissemination. The Napa County monitoring program relies on both publicly-owned and volunteered private wells. To fulfill its mission and garner community interest and support, the GRAC developed an outreach brochure and a series of fact sheets on specific topics, designed to implement the Monitoring Plan through voluntary participation. Ensuring groundwater sustainability is an adaptive process that maintains the ability of future generations to make choices about how they use groundwater resources. Monitoring is one of many steps in a larger adaptive cycle, along with evaluating progress toward meeting objectives, learning from whole systems data evaluation, revising objectives and activities, developing and implementing best management practices (BMPs), and adjusting BMPs as needed. This presentation describes the approaches that Napa County undertook to integrate water resources sustainability into County policies and programs in advance of California’s 2014 Sustainable Groundwater Management Act (SGMA). The County has developed an important foundation upon which to respond to SGMA requirements with community involvement and support.

Langridge, Ruth

Presentation Title
Institutional Approaches to Manage Groundwater in California:Evaluating Special Act Districts and Court Adjudications
Institution
University of California, Santa Cruz
Presentation
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Ruth_Langridge
Abstract
Groundwater in California is managed by four general institutional arrangements: 1) local groundwater management districts with limited regulatory powers, 2) special act districts that are provided with enhanced authority to establish rules for groundwater management, 3) court adjudications, where the court is generally focused on the assignment of private property rights to users, and 4) city and county ordinances. The 2014 Sustainable Groundwater Management Act (SGMA) enabled special act districts to exercise extra authority as needed to comply with SGMA, but exempted all 26 of the state’s adjudicated groundwater basins from the Act. Adjudicated groundwater basins and special act districts underlie large areas of Southern California and parts of the Central Coast including major agricultural regions. Working with the State Water Resources Control Board, our research provided two extensive reports that evaluated the history and current condition of all of California’s adjudicated basins and special act districts, along with potential future improvements that would better align these institutional management arrangements with SGMA goals for the sustainable management of groundwater. The presentation will provide a summary of our findings and highlight and compare the successes and challenges both special act districts and adjudicated basins face to achieve long-term sustainable groundwater management. It will include a review of: whether groundwater extractions are at or near a basins’ designated safe yield; whether overdraft conditions are reduced or eliminated over the long term; and the degree of collaboration and inclusion of community stakeholders in determining how the basin is managed. In addition to this overview, the presentation will highlight 4-6 basins with a significant agricultural presence and particularly interesting management challenges and solutions. For these basins, key issues that will be highlighted include: 1) the problem that precipitated the need for court adjudication or the formation of a special act district; 2) the management structure and current strategies to manage the basin, including how costs and benefits are distributed in the basin; 3) how safe yield and overdraft are defined and determined; and, 4) how well management is aligned with SGMA goals for sustainable management.

Loaiciga, Hugo

Presentation Title
Safe yield of large and small aquifers in agricultural regions
Institution
University of California
Presentation
Profile Picture
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Abstract
The safe yield is perhaps the most important management variable of an aquifer: it describes the maximum amount of groundwater that can be extracted from an aquifer without causing adverse effects. This paper compares four traditional methods and one novel method to estimate the safe yield in aquifers supporing agriculture. The paper also stresses the importance of adjusting groundwater extraction to protracted decline in recharge caused by drought. This is essential to protect against adverse impacts such as seawater intrusion in coastal aquifers and against land subsidence in layered aquifers with compresible aquitards. Two examples are presented illustrating this paper's methodology. One involves a 15 square mile aquifer supporting agriculture in the Carpinteria Valley, Santa Barbara, County. The other example concerns the 15000 square mile regional Edwards aquifer in south central Texas, which serves agricultural, aquatic, and urban functions. Both aquifers have detailed water-balance data for nearly one century, providing strong statistical reliability for the estimates of safe yield.

Lockwood, Brian

Presentation Title
Working toward Sustainable Groundwater Resources in an Uncertain Future
Institution
Pajaro Valley Water Management Agency
Presentation
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Lockwood
Abstract
Groundwater overdraft and seawater intrusion are two serious threats to the sustainability of groundwater resources in the Pajaro Valley. Located adjacent to the Monterey Bay in Central California, the Pajaro Valley is home to some of the most productive agricultural land in the country, producing more than $900 million/year of high value fruit, vegetable, and flower crops on approximately 28,500 irrigated acres. Average water usage in the valley is 55,000 acre-feet/year (AFY), with groundwater providing over 95% of the supply. Decades of groundwater overdraft have induced seawater intrusion, which was first documented in 1953. The Pajaro Valley Water Management Agency (Agency) was formed by an act of state legislature in 1984 to “efficiently and economically manage existing and supplemental water supplies in order to prevent further increase in, and to accomplish continuing reduction of, long-term overdraft.” The Agency developed its first Basin Management Plan (BMP) in 1993 and has updated twice since that time to reflect changing conditions. The BMP guides PVWMA’s efforts to reduce groundwater production and develop supplemental water supplies in an effort to balance the basin and halt seawater intrusion. Implementation of BMP projects occur in phases as funding allows. Between 2000 and 2009, the Agency constructed a managed aquifer recharge and recovery facility, a water recycling facility, and over 20 miles of distribution pipeline. While these projects reduced the magnitude of groundwater overdraft and seawater intrusion affecting the basin, they were not able to solve these problems entirely. In 2010 the Agency set out to identify the next phase of projects and programs needed to solve the water resource issues affecting the basin. The Agency’s extensive monitoring program, which includes among other things the metering of production wells and collection of groundwater levels, provided valuable data for the development of a regional scale hydrologic model that was used to estimate the basin’s water budget. The Pajaro Valley Hydrologic Model (PVHM), is an integrated hydrologic flow model that uses MODFLOW-OWHM, a code which fully couples the simulation of the use and movement of water throughout the hydrologic system, was created to help inform water resource management decisions. Stakeholder driven committees were formed to guide development of a suite of projects and programs to address a shortfall in the simulated water budget of ~12,000 AFY. The PVHM was later used to evaluate the effectiveness of proposed solutions toward attaining the co-equal goals of balancing the groundwater basin and stopping seawater intrusion. Following nearly two years of meetings, the planning committee decided on a suite of seven projects and programs that include conservation (5,000 AFY), optimizing the use of existing supplies (3,000 AFY), and developing new supplies (4,100 AFY). Projects being implemented in phases. If basin monitoring shows continued overdraft and/or seawater intrusion following the completion of each phase, additional projects identified in the BMP Update will be considered for implementation.

Matsumoto, Sandi

Presentation Title
Sustainable Groundwater Management: What We Can Learn from California’s Central Valley Streams
Institution
The Nature Conservancy
Presentation
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Abstract
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 conse¬quence, decisions about groundwater extractions have generally failed to address the resulting impacts to sur¬face 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 unde¬sirable results to groundwater levels and interconnected groundwater and surface water. These groundwater levels and areas of interconnection support ground¬water-dependent ecosystems (GDEs). Therefore, an important first step in sustainable groundwater man¬agement is to understand how groundwater pumping impacts surface water, including streams, and GDEs. To build the case for ecosystem protections now found in SGMA, The Nature Conservancy completed a study to illustrate how groundwater pumping is affecting streams and rivers in California’s Central Valley. The report uses an inte¬grated hydrologic model to reconstruct the historical impacts of groundwater use on groundwater levels and stream flow conditions. Our study focused on the state’s Central Valley because of its importance in California’s overall water supply. We used a model developed by the Department of Water Resources (DWR) to simulate the Central Valley’s hydrologic conditions during the years from 1922 to 2009, a period during which groundwater production grew threefold. The results reveal profound impacts to the stream flow conditions due to increased groundwater pumping. Across the Tulare Basin, San Joaquin Basin and Sacramento Valley these changes have differed in mag¬nitude, but share a similar trend. In areas with hydraulic connection between groundwater and surface water, increases in groundwater extraction continue to cause declines in groundwater levels that reduce stream flow. In many of these historically interconnected areas, declines in groundwater levels have caused segments of streams to change from gaining to losing reaches. In other words, portions of streams that once gained sur¬face flows from groundwater were converted to losing reaches, where surface flows are being lost to ground¬water. This reversal from gaining streams to losing streams has been most dramatic in the Tulare Basin, which converted largely by the 1920’s, with the San Joaquin Basin largely converting in the 1960’s. Our results indicate that the Sacramento Valley may be at a tipping point in this transformation, with some areas likely begin¬ning to lose stream flows to groundwater. The results of our study pre-date the extended drought that began in 2011 and it is likely that the drought has exacerbated stream depletions. In addition, our study illustrates that the effects of groundwater pumping can take years—even decades—to recover. This means that the full extent of the impacts of groundwater pumping during the drought will continue to plague California for many years.

Medellin-Azuara, Josue

Presentation Title
Economics of Long Term Groundwater: A Case Study for the Tulare Lake Basin, California
Institution
Center Watershed Sciences, University of California, Davis
Presentation
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Abstract
Groundwater serves as a buffer for droughts especially in areas with low precipitation and high reliance on imports. However, a steadily increasing proportion of permanent crops and persistent groundwater overdraft tend jeopardize long term sustainability of agriculture in some areas. Increased groundwater pumping especially during drought has the potential of increasing pumping costs due to lower water tables and loss of shallow wells in some areas. This study explores an area over the Tulare Lake Basin using hydro-economic model for agricultural production, information on well depth distribution and remote sensing data for land and water use. Results highlight economic net benefits of reducing irrigated areas, managing groundwater reserves sustainably and intensification in the crop mix. Challenges ahead in achieving sustainability in agriculture and groundwater are discussed.

Mehl, Steffen

Presentation Title
Can California Groundwater be Sustainably Managed with Agricultural Water Transfers? Effects on Aquifer Declines, Energy, and Food Production
Institution
California State University, Chico
Presentation
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mehl1
Abstract
California recently passed the Sustainable Groundwater Management Act, which requires that groundwater users develop sustainable groundwater management plans. However, California imports more water than any other place on Earth and is the largest producer of food in the USA. This creates competition between the “sustainable” uses of groundwater. Furthermore, recent droughts place even more pressure on water supplies (2013 was identified as the driest calendar year in California’s records). The ability to transfer water places pressure on northern California farmers to sell/lease their water, and decrease production and/or increase groundwater pumping to offset these transfers; however, the impacts of these transfers on regional economies and aquifer levels are often poorly understood. This work examines the effects of water transfers from northern California by using the United States Geological Survey’s Central Valley Hydrologic Model (CVHM) to simulate groundwater pumping scenarios corresponding to water transfers. The CVHM allows analysis of the spatial and temporal effects of pumping on the groundwater levels which are used to estimate: (1) the impact of additional groundwater pumping on aquifer levels, (2) the energy costs associated with additional lift due to aquifer declines throughout the region, and (3) the impacts associated with land fallowing for surface water transfers.

Melton, Forrest

Presentation Title
Operational Mapping of Evapotranspiration over Agricultural Land in the California Central Valley
Institution
NASA ARC-CREST
Presentation
Profile Picture
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Abstract
A key challenge in groundwater modeling in California is the limited historic data on groundwater withdrawals for irrigation. Satellite mapping of evapotranspiration (ET) is an efficient way to quantify consumptive water use and can play an important role in filling this data gap. Recent advances in satellite mapping of ET have made it possible to largely automate the process of mapping ET over large areas at the field-scale. This development allows for the creation of multi-decade timeseries that can be used to constrain groundwater models and improve estimates of groundwater withdrawals in agricultural regions.We present an approach for operational mapping of ET in California that leverages two automated ET mapping capabilities to estimate ET at the field scale over agricultural areas in the California Central Valley. We utilized the NASA Earth Exchange and applied a python-based implementation of the METRIC surface energy balance model and the Satellite Irrigation Management Support (SIMS) system, which uses a surface reflectance-based approach, to map ET over agricultural areas in the Central Valley. Though theoretically and computationally quite different from each other, the combined approach increases data continuity and reduces reliance on a single satellite or sensor. We present a comparison of results from both models, and discuss the strengths of limitations of the combined approach. We also discuss comparisons against ET measurements collected on commercial farms in the Central Valley and discuss implications for accuracy of the two different approaches. The objective of this analysis is to provide data that can support planning for the development of sustainable groundwater management plans, and assist water managers and growers in evaluating irrigation demand during drought events.

Mountjoy, Daniel

Presentation Title
On-Farm Recharge: Acceptance and use by farmers and water managers in the San Joaquin Valley, California
Institution
Sustainable Conservation
Presentation
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Abstract
Decades of groundwater depletion in California is recognized as a threat to the reliability and quality of water available to farms, communities and the environment. The new California Sustainable Groundwater Management Act (SGMA) requires local Groundwater Sustainability Agencies (GSAs) to develop plans to manage groundwater supplies to ensure long-term sustainable yields. Replenishing depleted groundwater supplies will be essential to achieving this balance. The current default for groundwater recharge – dedicated recharge basins – is costly, and requires the purchase and retirement of many acres of productive land in order to capture the infrequent but large flood flows needed to achieve balance.On-farm recharge is an innovative solution to get water into the ground without taking agricultural land out of production. It can be implemented quickly using existing irrigation surface canals during heavy floodwater conditions without investing in costly new infrastructure. Accelerating the replenishment of groundwater supplies through on-farm recharge can also reduce the extent to which GSAs may need to restrict groundwater pumping. The success of this new practice will depend on acceptance of the strategy by individual farmers and GSA managers.This presentation will present the findings of interviews and surveys with farmers who have experimented with applying floodwater on working cropland in excess of their crop’s water demand. In response to four years of drought and concerns about declining groundwater, farmers on over 100 fields with highly permeable soils volunteered to accept flood flows during the 2015-2016 flood season to accelerate groundwater recharge. In the absence of rigorous scientific data about the tolerance of crops on sandy soils to periodic over application of water, farmers growing 10 different crops as well as fallow ground were asked about the management decisions they make regarding acceptable timing and duration of water for recharge. The acceptable quantity of water applied in excess of crop demand also provides a starting point for determining the potential of this practice to address basin wide groundwater depletion under different cropping systems.The acceptance of this strategy also depends on acceptance by GSAs who must weigh the financial and social costs and benefits of alternative groundwater management methods. The presentation will compare the costs of on-farm recharge with dedicated recharge basins in terms of construction and operation expenses as well as potential incentives that may be needed to achieve widespread use. Unlike traditional recharge basins, on-farm recharge places individual farmers at greater risk of crop damage while their voluntary actions benefit all groundwater users in the basin. Information and decision support tools about the feasibility of on farm recharge will enable GSAs to consider on-farm recharge as a cost-effective and immediate option to include as part of their Groundwater Sustainability Plans..This presentation addresses the social and economic dimensions of on-farm recharge and complements presentations by other collaborators that address hydrologic infiltration potential, the effect on nitrate management and groundwater quality, and crop health. All these issues must be more fully understood before this strategy is promoted at scale to achieve groundwater sustainability goals.

Parker, Timothy

Presentation Title
Groundwater Management in Mexico – Embarking on New Horizons?
Institution
Parker Groundwater Management
Presentation
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Abstract
The main law governing water resources management in Mexico is the National Water Law of 1992, which lays out the top-down key legal functions and responsibilities of the National Water Commission (CONAGUA). CONAGUA's mission is to manage and preserve national water resources, working with society, to achieve water sustainability. CONAGUA administrates major federal programs to support investments in water supply, sanitation, irrigation, and manages key hydraulic facilities that meet most of the water demand in Mexico City. CONAGUA also owns and operates most dams in Mexico and the country's water monitoring network. The state Water Commissions are autonomous entities that generally fall under the authority of the State Ministry of Public Works. Their responsibilities and authorities vary between states and include water resources management, irrigation, water supply and sanitation services. Besides CONAGUA and the state Water Commissions, other entities including the Ministry of Finance, the Federal Congress, State Governments and State Congresses, Ministry of Environment and Natural Resources are important policy-makers in the sector.CONAGUA is responsible for issuing water use permits and levying groundwater extraction charges to help manage the demand versus supply. However, the total volume of water for which permits have been granted exceeds the total supply in some regions. Water resource pricing through extraction charges is carried out on the basis of the Federal Rights Law, which classifies the country in nine water scarcity zones. However, the major water user, agricultural, is exempt and charges are paid only by industry and municipal users, which considerably limits the effectiveness of the charge as a tool for water demand management.Through amendments of the National Water Law in 2004, two new entities were created intended to provide more local bottom up responsibilities and involvement: Basin Councils and Basin Agencies. The 26 basin councils created are advisory bodies that include representatives of the federal government, state and municipal governments, with at least half the council representing water users and Non-governmental organizations. The basin agencies are local decision-making bodies and regional administrative branches of CONAGUA.Despite progress and many achievements, Mexico still faces significant water resources challenges not uncommon to much of the modern word, including: 1) Increasing water scarcity2) Over-exploitation of freshwater resources, especially groundwater3) Increasing water quality degradation4) Sustainable water industry funding and finance 5) Modernization of facilities and services6) Improving agricultural irrigation efficiency7) Strengthening of local water institutions8) Climate change adaptation to periodic droughts and floodsRecognizing the need for further progress and to improve groundwater management, CONAGUA made the decision to begin work on groundwater management policy principles to use as a framework to amend the water resources law in the near future. The dialogue on developing groundwater management policy principles began in late 2015 and was continued through two working sessions at the Ninth International Symposium on Managed Aquifer Recharge (ISMAR9) in Mexico City in June 2016. This presentation will provide outcomes of the groundwater management discussions of ISMAR9, including the draft policy principles for groundwater management in Mexico.

Perrone, Debra

Presentation Title
California’s Sustainable Groundwater Management Act: A Perspective Looking Across the South-Western US
Institution
Stanford University
Video
Video Not Available
Presentation
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Abstract
As the 2015 New Year dawned on one of the worst droughts in the history of California, the state’s Sustainable Groundwater Management Act (SGMA) came into effect. The legislation is not only momentous in California’s legal history, but also it is significant in the context of western United States (US) groundwater legislation. This work analyzes the SGMA from the comparative perspective of groundwater legislation across the south-western US. We focus on the regulation of groundwater extraction in pursuit of sustainable use of the resource. We focus on five key elements in extraction permit (or, in the terminology of the SGMA, “allocation”) regimes: first, criteria for issuing groundwater permits; second, requirements to meter and report withdrawals; third, exemptions from permit requirements; and fourth, penalties for violating permit terms. Fifth, we explore how the overarching balance between state and local powers supports these elements. We compare the powers granted to local agencies in California with those available under permit regimes that apply broadly throughout the states of the south-west, as well as in “special groundwater management areas”, which typically impose more stringent requirements on groundwater permitting relative to “default” state groundwater laws. We developed a template and an associated codebook to record, in a standardized way, how each jurisdiction reflects these elements. Data were collected using a range of standard legal research techniques (e.g., legal text searches and analysis, reviewing secondary literature, interviews with state agency staff). These data enable us to demonstrate how these south-western permit regimes vary along several dimensions in relation to each of the permit regime elements.Relative to south-west states, we find that local agencies in California have the powers to establish relatively rigorous permit and allocation regimes, with comprehensive well registration, metering, and reporting of extraction, and relatively limited exemptions from these requirements. Nevertheless, California local agencies will not have the benefit of the stronger enforcement provisions available elsewhere in the south-west. Consistent with California’s local-centric model of groundwater governance, local agencies retain significant discretion in these matters, especially in relation to criteria for issuing permits. South-western permit regimes may provide useful models of regulatory options for California local agencies contemplating establishing a groundwater extraction permit or allocation regime. Under the SGMA, and for the first time, California local agencies will have a clear, broad-scale permit power with relatively few legal constraints, as well as accompanying powers related to metering, reporting, exemptions, and enforcement, which are vital to the effectiveness of a permit regime. But having these powers will not be sufficient to meet sustainability goals. History suggests that local agencies will need to overcome substantial practical and political obstacles to using these powers in order to ensure they contribute meaningfully to the pursuit of groundwater sustainability. Pointing to the precedents set by regimes in the south-west may also help to overcome these obstacles.

Reinelt, Peter

Presentation Title
To Maximize Net Benefits, Abolish or Limit Water Data Confidentiality to 1-5 Years
Institution
State University of New York at Fredonia
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Reinelt
Abstract
With water supplies constrained by prolonged drought and future climate change and water demands rising with population growth, California faces a future of increasing water scarcity and attendant impacts on water quality. Improvements in resource management will require greater integration of surface and groundwater supply quantity and quality, more extensive and accurate measurement of relevant water parameters, and storage of this critical information in comprehensive databases available to government planners, affiliated and independent researchers, and the public. However, in a recent assessment by state-funded groundwater quality researchers:Inconsistency and inaccessibility of data from multiple sources prevent effective and continuous assessment.… [W]e often faced insurmountable difficulties in gaining access to data already collected on groundwater and groundwater contamination… A statewide effort is needed to integrate diverse water-related data collection activities .... Comprehensive integration, facilitation of data entry, and creation of clear protocols for providing confidentiality as needed are key characteristics of such an integrated database structure.1The benefits to society from detailed, publicly accessible data has routinely been dismissed or ignored at the local resource agency level. Increasing scarcity demands that the unexamined consequences of “confidentiality as needed”, often leading to the continued acceptance of indefinite water data confidentiality, be thoroughly analyzed in light of the pressure on current water institutions and how they are likely to evolve.This paper frames the analysis of societal tradeoffs in a farming context with respect to the literatures on patents, proprietary information, emissions reporting law, and peer effects. We first analyze the physical properties of water (and contaminant) flows and the legal conventions governing its use. Both the physical and legal dimensions only exist in relationship between any extractive user and other extractive users, which constitute the public at large, as well as in relationship to societal benefits from non-extractive uses and the public trust.2 We then discuss the potential public and private benefits and losses of limiting or abolishing water data confidentiality. We conclude that permanent confidentiality is not in the public interest. Disclosure of water data can produce societal gains through better public water resource modeling, better monitoring and transparency of local water institutions charged with managing extractive and non-extractive uses leading to better performance, accountability, credibility and confidence in the integrity of laws governing water use, by reducing delays caused by those who use water data confidentiality as a barrier to the development and implementation of socially beneficial water quantity or quality regulations, and by encouraging more efficient private use of water.From the analysis, we identify two potential subsets of individual farming unit data for disclosure, either contemporaneously or after a fixed time delay. Recommended water data disclosure is limited to that which is necessary for the public purpose and structured to mitigate potential profit losses from disclosure of proprietary information.Finally, in light of water system security concerns, we discuss potential adjustments to the spatial resolution of readily accessible data or to methods for gaining accessibility to more precise locational data.1. Harter, Thomas and Jay R. Lund et al. of Center for Watershed Sciences, “Addressing Nitrate in California’s Drinking Water, With a Focus on Tulare Lake Basin and Salinas Valley Groundwater: Report for the State Water Resources Control Board Report to the Legislature, California Nitrate Project, Implementation of Senate Bill X2 1”, p. 74, January 2012.2. Qureshi, M., Andrew Reeson, Peter Reinelt, Nicholas Brosovic, Stuart Whitten, “Factors determining the economic value of groundwater”, Economics of Groundwater Management special issue, Eds. Reinelt, Brosovic, Qureshi, Hellegers, Hydrogeology Journal, International Association of Hydrogeologists, 2012.

Scherberg, Jacob

Presentation Title
Numerical evaluation of managed aquifer recharge as a conjunctive water resource management tool in the Walla Walla Basin
Institution
GeoSystems Analysis, Inc.
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Abstract
The Walla Walla Basin, located in Eastern Oregon and Eastern Washington, USA, faces challenges in sustaining an agricultural water supply while maintaining sufficient flow in the Walla Walla River (WWR) to sustain endangered fisheries. Managed Aquifer Recharge (MAR) is currently used in the basin to supplement groundwater used for summer irrigation to allow greater instream flow during dry summer months. The numerical groundwater-surface water model, Integrated Water Flow Model (IWFM), was calibrated to hydrological conditions in the Walla Walla Basin and applied to predict future hydrological conditions under current management practices (baseline model) and for three alternative water management scenarios. Alternative management scenarios assumed unlined canals were converted into pipelines to improve the efficiency of irrigation water deliveries and a concurrent reduction of diversions from the WWR during summer months. MAR is incrementally increased among the three management scenarios, with “Current MAR” using the current annual MAR input of 11.1 million cubic meters per year (Mm3/Y) at the seven currently active MAR sites, “Increased MAR” using 17.7 Mm3/Y among 22 MAR sites, and “Maximum MAR” using 29.3 Mm3/Y among 60 MAR sites. Model results indicate that canal piping without increased MAR will increase instream flow in the lower portions of the WWR by up to 0.20 m3/s relative to baseline conditions. The predicted impact of MAR on instream flow is minimal in the upper portion of the WWR. Under the “Increased MAR” and “Maximum MAR” scenarios summer flows in the lower portions of the WWR are predicted to increase by up to 0.45 m3/s and 0.51 m3/s, respectively, relative to baseline conditions due to an increase in groundwater return flows in the WWR and tributaries. Conversion of canals into pipelines is predicted to decrease seepage from canals as a source of groundwater recharge, resulting in decreased groundwater storage in the “Current MAR” scenario relative to the baseline model. Under “Increased MAR” and “Maximum MAR scenarios groundwater storage was predicted to be greater than baseline conditions. Model results indicate that canal piping in combination with increased MAR provides benefits for riparian and instream habitat by allowing for significantly increased summer flows in the WWR and inflowing tributaries, while stabilizing groundwater storage levels. This supports that MAR is a tool that can be used to apply conjunctive water management effectively in the Walla Walla Basin.

Schmidt, Kirk

Presentation Title
California Groundwater Management - the 21st Century Gordian Knot
Institution
Central Coast Water Quality Preservation, Inc.
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Abstract
Short deadlines and historic local conflicts make formation of a Groundwater Management Agency (GMA) and adoption of a Groundwater Management Plan a mirage for many under California’s new Sustainable Groundwater Management Act (SGMA). Success is determined by a 2020 plan submittal mandate, one that may only be possible with cooperative and compatible local agencies and objectives.Why? The Pajaro Valley Water Management Agency, one of 15 state special districts that were already tasked with managing critically overdrafted basins in California prior to the new SGMA legislation, has accomplished this daunting task. Their experience demonstrates that it takes two years and $500,000, plus existing staff time, to “revise” an existing plan and 18 months and $500,000 to devise and adopt a financing scheme, required environmental studies, and hold a rate-setting election. PVWMA’s prior experience, including a number of precedence-setting legal challenges, shows all of these steps need both be focused on a realistic basin plan and equally on the rate-setting benefits analysis.Local conflicts in San Luis Obispo, San Joaquin County and the Salinas Valley may cause both the formation and plan deadlines to be missed. There are three parts to this problem: 1) part of the problem is inherent in the state’s definition of a high priority basin; 2) non-compatible local objectives whether urban versus agriculture, or county versus irrigation district versus cities. Furthermore, the SGMA specifically claims not to alter existing property rights and the alternative of adjudication mean that some participants may exercise greater sway in formation and planning; 3) no funding -you need a GMA to write a plan, which will require money, you need money to first evaluate and then run a GMA. How do you structure a “benefits analysis” for a mere agency without an idea of the plan? Again, money is needed to implement the plan. Three times to the well may be two too many for some taxpayers. After all what is the downside to not completing the plan? The county or state takes over the basin, and they also have no taxing authority so, from the perspective of some taxpayers there is no downside to failure. Placing meters on wells is an apostate to many farmers. Very few agricultural wells in California are metered. PVWMA metered all large groundwater wells (pumping more than 10 acre feet per year) in 1994 and began charging a fee to pumpers to fund the cost of managing the basin. This will be an affront to some farmers – a notoriously self-reliant independent group.The Gordian Knot was a tightly wound ball of rope with no beginning or end visible to the observer. No one was able to untie it, so failed the test. Alexander the Great was confronted by the unsolvable riddle, analyzed it for a moment, then drew his sword and cut the knot in half. Problem solved. It is not certain if California can devise such a clean solution to the dilemma created by the SGMA.

Shilling, Fraser

Presentation Title
California Almond Water Footprint
Institution
University of California, Davis
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Abstract
The domestic and international media have recently focused on the water footprint of California almonds and have related the water footprint to water use and the drought. The water footprint is an index of the complete use of and impacts to water systems. It is the sum of water impacts from production of a good or service used by people. It is typically expressed per unit production, per region, or per capita. It goes beyond consideration of water use (e.g., from irrigation) and according to the International Standards Organization is similar to the life cycle analysis approach. Besides the problem of perception that California almonds have a large water footprint, there is the additional problem that the water footprint estimate quoted in the media is not accurate and has gradually improved over time. Finally, the many nutritional and economic benefits that almond production and almonds provide are lost in a water footprint calculation that report volume of water per unit weight of almonds. Almond production provides a large economic and employment benefit to California. Almonds are also high in food value, especially relative to other high water footprint foods, such as beef. We are calculating the water footprint in terms of economic benefit, protein (g), or total food benefit in order to provide a better representation of the benefits of almonds relative to the water footprint. Almond water footprints show a great deal of variability around the state based on yield, evapotranspiration (ET) rates, and recently updated crop coefficients (Kc). The lowest almond water footprints are in the southern San Joaquin Valley and the highest are in the northern Sacramento Valley. This is due primarily to differences in yields between north (low) and south (high). However, the agricultural water sources and water quality concerns that are present in the north vs. the south are also quite different. While current estimates of an average almond water footprint may be only slightly (+20%) revised by this research, we find almonds to have economic and health productivity advantages over other crops commonly grown in the region. Further, we see potential for management actions that reduce water footprints synergistically with greenhouse gas and other ecological footprint indicators.

Sneed, Michelle

Presentation Title
Evolution of Water Availability and Land Subsidence in California’s San Joaquin Valley
Institution
U.S. Geological Survey
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Abstract
The San Joaquin Valley covers about 26,000 km2 and is one of the most productive agricultural regions in California. Because the valley is semi-arid and the availability of surface water varies substantially from year to year and season to season, the agricultural industry developed a reliance on local groundwater for irrigation. Groundwater pumpage caused significant and extensive drawdowns, resulting in land subsidence at rates up to 0.3 meters per year. The completion of state and federal water distribution systems by the early 1970s eased the reliance on local groundwater as dependence shifted to diverted surface water. As a result, groundwater levels recovered and subsidence virtually ceased. In the last 20 years, however, land-use changes and an assortment of restrictions to surface-water availability—including droughts and environmental flows—have resulted in increased pumping and renewed land subsidence. The spatially variable subsidence has changed the land-surface slope in some places and caused operational, maintenance, and construction-design problems for water-delivery and flood-control canals as well as other infrastructure.The location, extent, and magnitude of land subsidence from the 1920s to 2015 were examined using Interferometric Synthetic Aperture Radar (InSAR), geodetic survey (spirit leveling and Global Positioning System surveys), extensometer, and continuous Global Positioning System (CGPS) data to estimate subsidence. Spatially and temporally dense data types are complementary and are needed to understand the mechanisms that underlie the spatial subsidence patterns and improve subsidence simulations. Since InSAR data became available in 1992, the comprehensive spatial coverage it provided has allowed the delineation of the spatial extent of subsidence: Geodetic survey, extensometer, and CGPS measurements show monthly, seasonal, and (or) inter-annual variations in subsidence rates at specific locations. Spirit-leveling surveys between the 1920s and 1970 indicated that more than half of the valley was affected by at least 0.3 m, and a local maximum exceeded 8 m of subsidence. Data from extensometers, combined with geodetic survey or CGPS data, indicated that compaction of sediments below the Corcoran Clay was the primary cause of subsidence. Data from extensometers, combined with other data sources, indicated that beginning around 1970, subsidence during the remainder of the 20th century occurred largely during drought periods. However, data from InSAR, geodetic surveys, extensometers, and CGPS during the 21st century showed subsidence patterns have changed, and in some circumstances, subsidence occurred irrespective of climatic conditions and was tied to land-use changes. Planning for the effects of subsidence in the San Joaquin Valley is important for water managers. As land use and surface-water availability continue to vary; long-term groundwater-level and subsidence monitoring, analysis, and modeling are critical to understanding the dynamics of historical and continued groundwater use resulting in water-level and groundwater-storage changes, and associated subsidence. Modeling tools, such as the USGS Central Valley Hydrologic Model, can be used in the evaluation of management strategies to mitigate adverse impacts due to subsidence while also optimizing water availability. This knowledge will be critical for successful implementation of recent legislation aimed toward sustainable groundwater use.

Vrain, Emilie

Presentation Title
Factors influencing the adoption of water pollution mitigation measures by farmers in England
Institution
Environmental Science Department
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Abstract
A range of interventions are available to influence the uptake of farm practices which mitigate groundwater pollution. Deciding which are the most appropriate for particular measures poses a challenge to policy makers. Whilst many measures remain voluntary, implementation will only be effective with the co-operation of stakeholders and evidence regarding the factors influencing measure uptake is crucial to aid policy design.Research conducted as part of the Demonstration Test Catchment (DTC) project explored the factors influencing farmer adoption of water pollution mitigation measures through three related surveys. Over two hundred farmers and farm advisors participated in interviews from three contrasting regions of England: the grassland dominated North West; the arable dominated East Anglia; and the mixed and dairy farming of the South West.Results from the two farmer surveys provided a baseline of current agricultural practices, insights regarding farmer attitudes to the adoption of other mitigation measures in the future and understanding of the motivations and barriers to the adoption of specific measures such as, cover crops, sub soiling and farm yard infrastructure. Results from the farm advisor interviews revealed the types of mitigation measures recommended by various advisors, which mechanisms (regulatory advice, financial incentives, signposting or voluntary approach) were being used to influence the uptake of measures, and whether differences occurred between sources of advice.The results illustrate the great diversity amongst the farming community, the range of factors influencing mitigation measure uptake and the differing complexities of farmers’ decisions to change their behaviour. Different combinations of interventions are required not only for each mitigation measure but also within the different regions surveyed. The importance of advice is illustrated but knowing which advisors are most suitable to deliver information and how is highlighted as being essential for policy design. Policy recommendations are provided as to what needs to change to influence adoption of specific mitigation measures to improve catchment management and advice provision.

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