Who Owns the Water in California

Under California’s Water Code, “water within the State is the property of the people of the State” – water rights holders only hold a right to use water subject to certain restrictions.  In California, water ownership is complex: Who owns the water in California?

  • The State holds significant ownership
  • The federal government owns H2O on federal lands
  • Private entities own groundwater beneath properties
  • Indigenous tribes hold water rights per treaties
  • Riparian landowners have rights along waterways
  • Prior Appropriation grants rights based on seniority
  • Public Trust Doctrine

Water ownership in California is complicated subject with ownership rights held by the state government, federal agencies, private entities, and indigenous tribes. The state and federal governments own significant portions of surface water and designated groundwater basins, while private individuals, corporations, and agricultural enterprises hold water rights through various legal mechanisms.


Water is not merely a resource in California; it is a lifeline, essential for sustaining ecosystems, agriculture, industry, and human life. The state’s complex network of rivers, lakes, aquifers, and reservoirs serves as the backbone of its economy and communities. Understanding the ownership of this vital resource is crucial for comprehending California’s water management landscape.

California’s economy, the largest in the United States, relies heavily on water. The state is a leading agricultural producer, responsible for a significant portion of the nation’s fruits, vegetables, and nuts. Additionally, water supports various industries, including technology, manufacturing, and tourism. Moreover, water plays a fundamental role in sustaining ecosystems, protecting biodiversity, and maintaining the state’s natural beauty.

The ownership of water in California is governed by a complex legal framework that balances competing interests and priorities. At its core are principles derived from Spanish and English common law, as well as indigenous water management practices. The state’s water ownership system encompasses diverse rights and regulations, including the Prior Appropriation Doctrine, Riparian Rights, and Groundwater Regulation. Understanding these mechanisms is essential for navigating California’s intricate water rights landscape.

Who Owns the Water in California

Water ownership in California is a multifaceted issue governed by a complex legal framework. The state government holds significant ownership of water resources, including surface water and designated groundwater basins. Federal agencies also own water on federal lands, such as national parks and forests. Private entities, including individuals, corporations, and agricultural enterprises, hold water rights granted through various legal mechanisms.

Indigenous tribes possess water rights recognized through historical treaties and court decisions. Ownership of water resources is divided among these entities, each with distinct rights and responsibilities. Water allocation is governed by principles of equity, efficiency, and sustainability, balancing competing interests and priorities.

The management of water resources requires collaboration and coordination among stakeholders to ensure equitable access and sustainable use. Despite challenges, including population growth and climate change, California continues to work towards effective water governance and management for the benefit of present and future generations.

The History of California Water

Before the arrival of European settlers, indigenous communities in California practiced sophisticated water management techniques tailored to their local environments. These practices varied across different tribes and regions but often involved the construction of irrigation systems, such as canals and weirs, to divert water for agriculture. Additionally, indigenous peoples had deep cultural and spiritual connections to water, viewing it as sacred and central to their way of life.

With the arrival of Spanish explorers in the 16th century and later Mexican settlers in the 18th and 19th centuries, California’s water management practices underwent significant changes. Spanish and Mexican colonizers introduced new irrigation methods, such as the acequia system, which utilized communal water channels to distribute water for agricultural purposes. These systems laid the groundwork for later water infrastructure development in California.

The development of formal water law in California can be traced back to the mid-19th century, following the state’s admission to the United States in 1850. Influenced by both Spanish and English legal traditions, early water laws in California sought to establish clear rules for water allocation and use. The adoption of the riparian rights doctrine, which grants landowners adjacent to waterways the right to use water for reasonable and beneficial purposes, reflected the state’s agrarian economy and abundant surface water resources.

As California’s population grew and water demand increased, particularly during the Gold Rush era, conflicts over water rights became more prevalent, prompting the state government to enact legislation to regulate water use and resolve disputes. This period marked the beginning of California’s modern water law framework, which continues to evolve to this day in response to changing environmental, social, and economic conditions.

Water Law in California

Prior Appropriation Doctrine

The Prior Appropriation Doctrine, also known as “first in time, first in right,” is a fundamental principle of water law in California. Under this doctrine, the right to use water is based on the California Water Sources principle of priority, with earlier users having superior rights over later users. This system prioritizes efficiency and encourages the productive use of water resources.

Water rights are typically established by obtaining permits or licenses from the state government, and users must adhere to specific conditions and limitations outlined in their permits. The Prior Appropriation Doctrine is particularly relevant in regions with limited water availability, such as arid areas and during drought conditions.

Riparian Rights

Riparian rights are another key aspect of California’s water law, particularly in areas where surface water sources, such as rivers and streams, are abundant. Under riparian rights doctrine, landowners whose property borders a waterway have a right to use water for reasonable and beneficial purposes, such as irrigation, domestic use, and livestock watering.

Unlike the Prior Appropriation Doctrine, riparian rights are not based on priority of use but rather on the ownership of adjacent land. However, riparian rights are subject to the doctrine of reasonable use, which prohibits wasteful or excessive water consumption that harms other riparian users or the environment.

Groundwater Regulation

In recent years, the regulation of groundwater has become increasingly important in California due to overdrafting and depletion of aquifers. Unlike surface water, which is governed primarily by surface water rights systems like riparian and appropriative rights, groundwater management historically lacked comprehensive regulation.

However, the passage of the Sustainable Groundwater Management Act (SGMA) in 2014 marked a significant milestone in groundwater regulation in California.

SGMA requires the formation of groundwater sustainability agencies (GSAs) to develop and implement groundwater sustainability plans (GSPs) aimed at achieving sustainable groundwater management within designated groundwater basins. The implementation of SGMA represents a shift towards more sustainable and integrated management of both surface and groundwater resources in California.

Public Trust Doctrine

The Public Trust Doctrine is a legal principle derived from ancient Roman law that asserts the government’s obligation to protect and preserve certain natural resources, including water, for the benefit of the public. In California, the Public Trust Doctrine applies to navigable waters and their associated natural resources, such as beaches, wetlands, and wildlife habitat. This doctrine imposes a duty on the state government to manage these resources for the use and enjoyment of present and future generations. The Public Trust Doctrine has played a significant role in shaping California’s environmental policy, particularly in the regulation of water resources and the protection of aquatic ecosystems.

Water Ownership Entities in California

State Ownership

Water Challenges Facing California's Central Valley | FGS
Water Challenges Facing California’s Central Valley

The state of California holds significant ownership of water resources within its boundaries. This ownership extends to navigable waterways, such as rivers, lakes, and streams, as well as groundwater basins designated as part of the state’s public trust resources.

As a trustee of these resources, the state has a legal responsibility to manage them in the public interest, ensuring equitable access and sustainable use for current and future generations. State agencies, such as the California Department of Water Resources (DWR) and the State Water Resources Control Board (SWRCB), play key roles in managing and regulating water resources on behalf of the state government.

Federal Ownership

The federal government also holds ownership interests in certain water resources in California, particularly those located on federal lands or reserved for specific purposes, such as national parks, forests, and military installations.

Examples of federally owned water resources in California include reservoirs managed by the Bureau of Reclamation (e.g., Hoover Dam, Shasta Dam) and waterways under the jurisdiction of federal agencies like the U.S. Forest Service and the National Park Service. Federal ownership often involves complex jurisdictional issues and cooperative management arrangements between federal, state, and local entities to ensure the effective stewardship of these resources.

 Private Ownership

In addition to government ownership, water resources in California are also owned and managed by private entities, including individuals, corporations, and agricultural and industrial enterprises.

Private ownership rights may arise from various legal doctrines, such as riparian rights, appropriative rights, and private contracts. Landowners with riparian rights can use water from adjacent waterways for reasonable and beneficial purposes, while appropriative rights holders obtain water rights through permits or licenses issued by the state government. Private ownership of water resources often coexists with regulatory oversight and is subject to compliance with applicable laws and regulations governing water use and management.

California Water Rights Allocation

Prior Appropriation System

The Prior Appropriation System, also known as “first in time, first in right,” governs water allocation in California based on the principle of priority. Under this system, water rights are established by the order of appropriation, with earlier users having superior rights over later users during times of scarcity. Water rights holders must use water for beneficial purposes and comply with the conditions outlined in their permits or licenses. The Prior Appropriation System is particularly relevant in regions with limited water availability, where competition for water resources is high. During droughts or water shortages, water rights are prioritized based on seniority, ensuring that older rights holders receive their allocated share before newer rights holders.

Riparian Rights

Riparian rights allocate water to landowners whose property borders a waterway, granting them the right to use water for reasonable and beneficial purposes. Unlike the Prior Appropriation System, riparian rights are not based on priority of use but rather on ownership of adjacent land. Riparian rights holders have a continuous and uninterrupted right to use water from the waterway, subject to the doctrine of reasonable use, which prohibits wasteful or excessive consumption that harms other riparian users or the environment. Riparian rights are typically associated with areas where surface water sources, such as rivers and streams, are abundant, and play a significant role in water allocation in those regions.

 Groundwater Management

Groundwater management in California involves regulating the extraction and use of groundwater from underground aquifers to ensure sustainability and prevent overdrafting. Historically, groundwater was largely unregulated, leading to depletion of aquifers and subsidence in certain regions.

The Sustainable Groundwater Management Act (SGMA), enacted in 2014, represents a significant shift in groundwater management by requiring the formation of groundwater sustainability agencies (GSAs) to develop and implement groundwater sustainability plans (GSPs) for designated groundwater basins. These plans aim to achieve sustainable groundwater management by establishing goals, objectives, and actions to prevent undesirable impacts, such as groundwater overdraft, depletion of storage, land subsidence, and degradation of water quality. SGMA emphasizes local control and collaboration among stakeholders to achieve long-term groundwater sustainability.

California’s Water Challenges and Controversies

One of the most pressing challenges in California’s water management is the overallocation of water resources, exacerbated by recurrent droughts and increasing water demand. The state’s complex water rights system, which includes both surface water and groundwater allocations, has led to competition and conflicts among various users, including agricultural, urban, and environmental interests.

Front yard water wise plans - City of Roseville
Front yard water wise plans

During droughts, water scarcity intensifies, highlighting the need for effective water allocation and conservation measures. Overallocation of water resources can have adverse effects on ecosystems, agriculture, and communities, necessitating adaptive management strategies and collaborative approaches to address competing demands and ensure equitable access to water resources.

California’s diverse ecosystems and wildlife habitats depend on healthy water systems to support biodiversity and ecological functions. However, water diversions, pollution, habitat destruction, and other human activities have resulted in significant environmental degradation and loss of habitat. Environmental concerns related to water management include habitat fragmentation, altered hydrology, water pollution, invasive species, and the decline of native species populations.

Balancing water allocations to meet human needs while protecting and restoring aquatic ecosystems poses a significant challenge, requiring integrated approaches that consider ecological, social, and economic factors. Efforts to enhance environmental flows, restore habitat connectivity, and improve water quality are essential to safeguarding California’s natural heritage and ensuring the long-term sustainability of its water resources.

Tribal water rights are an important aspect of California’s water management landscape, stemming from historical treaties, agreements, and court decisions that recognize Native American tribes’ rights to water resources. However, tribal water rights have often been marginalized or overlooked in water allocation decisions, leading to conflicts and legal disputes between tribes, government agencies, and other water users.

ribal water rights encompass various uses, including domestic, agricultural, cultural, and ceremonial purposes, and are integral to tribal sovereignty and self-determination. Recognizing and upholding tribal water rights is essential for promoting tribal sovereignty, advancing tribal water security, and honoring treaty obligations. Collaborative approaches that engage tribal governments, stakeholders, and regulatory agencies are crucial for resolving disputes, protecting tribal water rights, and achieving equitable water allocation outcomes.

The Future of California Water

The future of California’s water presents both challenges and opportunities as the state grapples with growing population, climate change, and competing demands for limited water resources. Sustainable water management strategies will be essential for addressing these challenges, including enhancing water conservation, improving water efficiency, and investing in water infrastructure.

Water conservation and efficiency | | Wisconsin DNR
Water conservation and efficiency

Legal reforms and policy recommendations are needed to strengthen water governance, promote equitable water allocation, and protect environmental resources. By embracing principles of sustainability, collaboration, and innovation, California can navigate its water challenges and build a more resilient and prosperous future for all residents.

Looking ahead, sustainable water management strategies will be critical for addressing the challenges posed by population growth, climate change, and competing water demands in California. Sustainable water management encompasses a range of practices aimed at optimizing water use, enhancing water efficiency, and protecting water quality and ecosystems. Key strategies include:

  1. Water Conservation and Efficiency: Implementing water conservation measures and promoting efficient water use in urban, agricultural, and industrial sectors to reduce water demand and minimize wastage.
  2. Integrated Water Resources Management: Adopting integrated approaches that consider the interconnectedness of surface water and groundwater systems, as well as the needs of diverse stakeholders, to achieve more holistic and sustainable water management outcomes.
  3. Ecosystem Restoration and Protection: Investing in habitat restoration, watershed protection, and ecosystem-based approaches to enhance water quality, restore natural hydrological processes, and support healthy aquatic ecosystems.
  4. Climate Resilience and Adaptation: Developing adaptive management strategies and infrastructure improvements to address the impacts of climate change, such as droughts, floods, sea-level rise, and altered precipitation patterns, on water availability and reliability.
  5. Public Education and Engagement: Increasing public awareness and engagement on water issues through outreach, education, and community involvement to foster a culture of water stewardship and collective responsibility.

By implementing these sustainable water management strategies, California can better prepare for future water challenges while safeguarding its water resources for future generations.

In addition to sustainable water management strategies, legal reforms and policy recommendations are needed to enhance California’s water governance framework and address existing gaps and inefficiencies. Key areas for reform include:

  1. Strengthening Groundwater Regulation: Enhancing the implementation and enforcement of the Sustainable Groundwater Management Act (SGMA) to achieve sustainable groundwater management goals, improve data monitoring and reporting, and streamline groundwater permitting and adjudication processes.
  2. Updating Water Rights Administration: Modernizing California’s water rights administration system to improve transparency, accountability, and efficiency in water allocation and permitting processes, while ensuring equitable access and protection of environmental flows.
  3. Promoting Tribal Water Rights Recognition: Upholding and respecting tribal water rights through meaningful consultation, collaboration, and engagement with tribal governments and stakeholders in water planning, decision-making, and resource management processes.
  4. Integrating Water and Land Use Planning: Incorporating water considerations into land use planning and development decision-making processes to minimize water demand, reduce land use conflicts, and promote sustainable growth and development.
  5. Investing in Water Infrastructure: Investing in the maintenance, rehabilitation, and expansion of water infrastructure, including dams, reservoirs, pipelines, and water treatment facilities, to improve water supply reliability, water quality, and water distribution efficiency.

By implementing these legal reforms and policy recommendations, California can strengthen its water governance framework, enhance water security, and promote more sustainable and equitable water management practices statewide.


In conclusion, California’s water ownership dynamics are shaped by a complex legal framework that governs the allocation, management, and use of water resources across the state. Ownership of water resources is divided among various entities, including the state government, federal agencies, private landowners, and indigenous tribes, each with distinct rights, responsibilities, and interests in water allocation and management.

From the Prior Appropriation System to riparian rights and groundwater regulation, California’s water ownership landscape reflects a rich history of legal, cultural, and environmental influences that continue to shape water governance in the state.

Balanced water allocation is essential for sustaining California’s economy, environment, and communities in the face of growing water challenges and uncertainties. Achieving a balance between competing water demands requires equitable and efficient allocation mechanisms that prioritize water conservation, environmental protection, and social equity. By considering the needs of all stakeholders and adopting integrated water management approaches, California can enhance water security, promote resilience to climate change, and protect its natural resources for future generations.

Looking ahead, equitable water management will be crucial for ensuring sustainable water use and resilience in California. This entails addressing historical inequities, fostering collaboration and partnership among diverse stakeholders, and promoting inclusive decision-making processes that prioritize the needs of marginalized communities, tribal nations, and future generations. By embracing principles of equity, justice, and sustainability, California can navigate its water challenges and build a more resilient and prosperous future for all.


California Department of Water Resources-The California Water System


  1. How is water allocated in California? Water allocation in California is governed by a complex legal framework that includes principles of prior appropriation, riparian rights, and groundwater regulation. Water rights holders must adhere to conditions outlined in permits or licenses issued by state agencies, and allocations are prioritized based on seniority during times of scarcity.
  2. What are the challenges in California’s water management? Challenges in California’s water management include overallocation of water resources, droughts, environmental degradation, and conflicts among competing water users. Addressing these challenges requires sustainable water management strategies, collaborative decision-making processes, and investments in water infrastructure and conservation.
  3. How does California regulate groundwater? California regulates groundwater through the Sustainable Groundwater Management Act (SGMA), which requires the formation of groundwater sustainability agencies (GSAs) to develop and implement groundwater sustainability plans (GSPs) for designated groundwater basins. SGMA aims to achieve sustainable groundwater management to prevent overdrafting and depletion of aquifers.
  4. What role do federal agencies play in California’s water management? Federal agencies, such as the Bureau of Reclamation and the U.S. Forest Service, play significant roles in California’s water management, particularly on federal lands and water projects. These agencies own and manage water infrastructure, reservoirs, and waterways, and collaborate with state and local entities on water-related issues.
  5. How can individuals and communities contribute to water conservation in California? Individuals and communities can contribute to water conservation in California by adopting water-efficient practices, such as reducing outdoor water use, fixing leaks, installing water-saving devices, and landscaping with drought-tolerant plants. Additionally, supporting policies and initiatives that promote water conservation and sustainability can help address water challenges at the local and statewide levels.
  6. What are the future perspectives for water management in California? The future of water management in California will involve implementing sustainable water management strategies, enhancing regulatory frameworks, investing in water infrastructure, and promoting collaboration among stakeholders. Addressing challenges such as population growth, climate change, and competing water demands will require innovative solutions and collective efforts to ensure the long-term sustainability of California’s water resources.

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