Madera Subbasin Joint Groundwater Sustainability Plan

Madera Subbasin Coordination Committee | January 31st, 2022

The Madera Subbasin is identified by California Department of Water Resources (DWR) as a critically overdrafted basin. Therefore, the Madera Subbasin GSAs must develop,

The Madera Subbasin is identified by California Department of Water Resources (DWR) as a critically overdrafted basin. Therefore, the Madera Subbasin GSAs must develop, adopt, and submit a GSP (or GSPs) to DWR for the entire Madera Subbasin by January 31, 2020. The Madera Subbasin is managed by seven GSAs, of which four (City of Madera GSA, Madera Irrigation District GSA, Madera County GSA, and Madera Water District GSA) have developed a joint GSP (attached here) and three (Gravelly Ford Water District GSA, New Stone Water District GSA, and Root Creek Water District GSA) have developed individual GSPs.

Managed Aquifer Recharge in California: Four Examples of Managed Groundwater Replenishment Across the State

American Geosciences Institute (AGI) | September 29th, 2017

In California, surface water from rainfall, snowmelt, and distant rivers rarely meets the state’s urban and agricultural water needs. Groundwater is an essentia

In California, surface water from rainfall, snowmelt, and distant rivers rarely meets the state’s urban and agricultural water needs. Groundwater is an essential water source, providing 35% of the fresh water used in California. However, when groundwater is used more rapidly than it is naturally replenished, groundwater management becomes necessary. One of the tools used by groundwater managers is managed aquifer recharge (MAR). Aquifers, the porous rocks and sediments that hold and transmit groundwater, are naturally replenished by surface water that seeps into the ground. MAR enhances the recharge rate by creating artificial streams and ponds where water trickles into the ground, or by using wells to directly inject water underground. MAR can also be used to improve groundwater quality and prevent some of the negative consequences of groundwater depletion, like ground sinking (subsidence) or the intrusion of salty groundwater from the oceans into coastal freshwater aquifers. Because of its arid climate and large population, California is home to some of the oldest and largest MAR projects in the United States. This case study highlights four of these projects, covering almost a century of MAR and water security in California.

Mapping Aquifer Systems with Airborne Electromagnetics in the Central Valley of California

National Groundwater Association (NGWA) | March 9th, 2018

The passage of the Sustainable Groundwater Management Act in California has highlighted a need for cost-effective ways to acquire the data used in building conceptual mo

The passage of the Sustainable Groundwater Management Act in California has highlighted a need for cost-effective ways to acquire the data used in building conceptual models of the aquifer systems in the Central Valley of California. One approach would be the regional implementation of the airborne electromagnetic (AEM) method. We acquired 104 line-kilometers of data in the Tulare Irrigation District, in the Central Valley, to determine the depth of investigation (DOI) of the AEM method, given the abundance of electrically conductive clays, and to assess the usefulness of the method for mapping the hydrostratigraphy. The data were high quality providing, through inversion of the data, models displaying the variation in electrical resistivity to a depth of approximately 500 m. In order to transform the resistivity models to interpreted sections displaying lithology, we established the relationship between resistivity and lithology using collocated lithology logs (from drillers’ logs) and AEM data. We modeled the AEM response and employed a bootstrapping approach to solve for the range of values in the resistivity model corresponding to sand and gravel, mixed coarse and fine, and clay in the unsaturated and saturated regions. The comparison between the resulting interpretation and an existing cross section demonstrates that AEM can be an effective method for mapping the large-scale hydrostratigraphy of aquifer systems in the Central Valley. The methods employed and developed in this study have widespread application in the use of the AEM method for groundwater management in similar geologic settings.

Maps, Models, and Mystery: Interconnected Groundwater and the Public Trust

American Bar Association (ABA) | August 10th, 2019

Walk into the office of any water law practitioner, anywhere, and you might think you made a wrong turn and walked into the office of your local cartographer. We are a p

Walk into the office of any water law practitioner, anywhere, and you might think you made a wrong turn and walked into the office of your local cartographer. We are a profession that depends on, and you might even say reveres, a good map. Rights to water flowing in surface streams are fundamentally defined by geography, and maps have long been a requirement of appropriation and essential evidence of riparian ownership. In turn, injury to a surface water right is determined by physics, as the topography of the land establishes the linear relation of impacts from other diversions, whether it be upstream (cause), or downstream (affected). In homage to these principles, some hydrologists will orient their maps top-to-bottom as upstream to downstream, rather than north to south. In our practice, gravity is our compass. Upending the convenient simplicity of rivers and streams flowing from mountaintop to ocean are alluvial and glacial valleys, in which unconsolidated sediment serve as giant sponges and blocks of fractured rock contain hidden stores of oftentimes ancient waters. Through these geologic features, hidden beneath the surface, water percolates, flows, and moves across the landscape. These subsurface waterbodies interconnect with surface streams and changes in the groundwater basin, whether due to drought or artificial extractions, and influence surface flow on a time scale ranging from minutes to centuries. To understand the relationship with any hope of precision, we need much more than a map; we need a hydrogeologist and a whole lot of data. All of this is by way of introducing two themes of emerging law in California that stand to influence trends beyond the state: (1) the legal relevance of interconnected groundwater to surface flows in protecting instream uses, and (2) recognition in the law of the need to understand and manage these interconnected waters.

Martis Valley Groundwater Basin Sustainable Groundwater Management Act Alternative Submittal

Truckee Donner Public Utility District (TDPUD) | December 22nd, 2016

McMullin Area Groundwater Sustainability Agency Groundwater Sustainability Plan

McMullin Area Groundwater Sustainability Agency (MAGSA) | November 6th, 2019

Measuring What Matters: Setting Measurable Objectives to Achieve Sustainable Groundwater Management in California

Union of Concerned Scientists | September 1st, 2015

Groundwater supplies between 30 and 50 percent of California’s water supply, depending on precipitation, and represents a storage reservoir that is over three times gre

Groundwater supplies between 30 and 50 percent of California’s water supply, depending on precipitation, and represents a storage reservoir that is over three times greater than available surface water storage. The California Water Action Plan (CNRA, CDFA, and CEPA 2014) identifies groundwater as “a critical bu?er to the impacts of prolonged dry periods and climate change on our water system.” Many groundwater basins have historically experienced significant chronic overdraft and related negative impacts. California’s ongoing drought helped spur the state to enact legislation to strengthen local control and management of groundwater basins. Governor Jerry Brown signed the threebill package (AB 1739, SB 1168, SB 1319), known as the Sustainable Groundwater Management Act (SGMA), into law on September 16, 2014. SGMA represents California’s attempt to regulate groundwater comprehensively for the first time in the state’s history. SGMA, which went into e?ect on January 1, 2015, lays out a process and a timeline for local agencies to achieve sustainable management of groundwater basins (see Box 1). It also provides tools, authorities, and deadlines meant to lead to achievement of the legislation’s purpose. For local agencies involved in implementation, the requirements are significant and are expected to take many years to accomplish. While setting measurable objectives is a new requirement, it is by no means a new concept in natural resource management. This report summarizes the theory and practice of setting measurable objectives for groundwater management, using examples from California and elsewhere. The goal is to begin to develop a shared knowledge base and to identify key features of e?ective measurable objectives.

Merced Groundwater Subbasin Groundwater Sustainability Plan

Merced Subbasin Groundwater Sustainability Agency (MSGSA) | November 12th, 2019

Merced Groundwater Subbasin Groundwater Sustainability Plan (Revised)

Merced Subbasin Groundwater Sustainability Agency (MSGSA) | July 6th, 2022

Due to size, this file has been divided into six part. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6

Due to size, this file has been divided into six part. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6

Mid-Kaweah Groundwater Sustainability Agency 2022 First Amended Groundwater Sustainability Plan

Mid-Kaweah Groundwater Sustainability Agency (MKGSA) | July 27th, 2022

Due to size, this file has been divided. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8, Part 9

Due to size, this file has been divided. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8, Part 9