Water is not a free resource in California. The right to use it is a property right. It is governed by a complex body of law that can significantly affect what a landowner can do with their land. A ranch that depends on a creek for irrigation, a development project requiring a new well, or a rural parcel at the edge of a water district’s service area: each involves water rights issues that can determine whether a land use is viable, who can use available water, and what happens when demand exceeds supply.
California water rights law is among the most complicated in the United States. It blends common law doctrines, state statutes, regulatory oversight, and constitutional protections in ways that can be difficult to navigate without understanding the underlying framework. This article explains the legal concepts most relevant to California property owners. It focuses on disputes that arise in real estate, agricultural, and development contexts.
California’s Dual Water Rights System
California operates under a dual system of water rights. Riparian rights apply to surface water adjacent to property. Appropriative rights apply to water diverted from a source and put to beneficial use, regardless of whether the diverter owns land adjacent to the source. These two systems operate simultaneously and can conflict with each other.
The California State Water Resources Control Board (SWRCB) is the primary state agency responsible for water rights administration. It issues water rights permits for appropriative uses and adjudicates water rights disputes. Understanding how the SWRCB’s oversight intersects with private property rights is essential for any California landowner dealing with water issues.
Priority and the “First in Time” Principle
Appropriative water rights in California follow a priority system. Senior rights holders have first claim on available water in times of shortage. Junior rights holders may receive no water at all when supply falls short of demand. This seniority principle is the central mechanism for allocating scarce surface water.
In a drought year, the SWRCB may issue curtailment orders cutting off junior water rights holders from diversions. Property owners and agricultural operators who hold only junior appropriative rights may find their water supply significantly reduced or eliminated during dry periods. The priority status of a water right is one of the most critical facts in any water rights analysis.
Riparian Rights: What They Are and What They Cover
Riparian rights attach to land that borders a natural watercourse. A property owner whose land touches a river, creek, or stream generally has the right to use the water flowing past the property. These rights come from land ownership itself. They do not require a permit or separate legal action.
Riparian rights allow landowners to make reasonable use of water for beneficial purposes on their property. California law limits these rights through the “reasonable use” standard. A riparian rights holder cannot divert so much water that it materially harms other riparian users along the same watercourse. These rights are proportional and correlative, not exclusive.
What Riparian Rights Do Not Cover
Riparian rights do not travel with water diverted off the riparian parcel. A landowner cannot divert water from a stream and use it on a non-adjacent parcel while claiming riparian rights. The right is tied to the land bordering the water source.
Riparian rights are also not absolute against appropriative rights holders. California’s 1928 constitutional amendment, Article X, Section 2 of the California Constitution, limits all water rights to reasonable and beneficial use. A riparian right holder who leaves water unused while an appropriator puts it to beneficial use may find a court balancing those interests under the reasonableness standard.
Riparian Rights in Real Estate Transactions
Riparian rights can be a significant component of a property’s value, particularly for agricultural land, ranches, and rural properties. When a riparian parcel is subdivided, the riparian right may not transfer to all subdivided portions. Whether it does depends on how the property was divided and whether the resulting parcels remain adjacent to the watercourse.
Buyers of riparian properties benefit from understanding what those rights cover, what limitations apply, and whether any prior agreements or adjudications affect the right. A property listing that references “water rights” may not specify whether those rights are riparian, appropriative, or based on some other legal basis.
Appropriative Water Rights
Appropriative water rights allow a person to divert water from a surface source and use it for a beneficial purpose, even without owning land adjacent to the source. These rights are acquired by diverting water and putting it to use, and in modern California practice, by obtaining a permit from the SWRCB.
The California Department of Water Resources (DWR) and the SWRCB jointly administer California’s water supply planning and rights systems. For most new appropriative rights, a party seeking to divert water must obtain a permit from the SWRCB through the Water Right Permit process. Pre-1914 rights, meaning rights established before the Water Commission Act took effect, can exist without a permit and carry senior priority status.
Permits, Licenses, and Post-1914 Rights
Modern appropriative rights for post-1914 diversions require a permit issued by the SWRCB. The permit specifies the quantity of water, the diversion point, the purpose of use, and the place of use. Once the water is actually put to use under the permit conditions, the SWRCB may issue a license confirming the right. The process and current permit conditions are explained in the SWRCB’s water rights program resources.
A permit does not guarantee access to water in drought years. It grants the right to divert, but the priority of that right relative to senior users determines how much water is actually available. Junior permit holders may be curtailed before senior users.
Beneficial Use Requirement
All California water rights, whether riparian or appropriative, are conditioned on beneficial use. Water diverted but not put to beneficial use can be forfeited or limited. The beneficial use doctrine prevents hoarding and encourages efficient use of a scarce resource.
What constitutes beneficial use is defined broadly: irrigation, municipal and industrial supply, livestock watering, recreation, and environmental flows can all qualify. Diverting water and allowing it to go to waste, or using more than necessary for the stated purpose, can jeopardize a water right over time.
Prescriptive Water Rights
California recognizes prescriptive water rights in some circumstances. A person who diverts and uses water openly, notoriously, and adversely to the legal rights holder for five continuous years may acquire a prescriptive right. This doctrine is analogous to adverse possession for land.
Prescriptive water rights are relatively rare and are often disputed. Establishing a prescriptive right requires evidence that the use was adverse, not permissive. If the original rights holder consented to the use, even informally, the prescriptive clock does not run. This distinction between adverse and permissive use is often the central issue in prescriptive water rights disputes.
Groundwater Rights in California
Groundwater law in California has historically differed significantly from surface water law. For most of California’s history, landowners had broad rights to pump groundwater beneath their property under the overlying rights doctrine. That landscape changed significantly with the Sustainable Groundwater Management Act.
The Overlying Rights Doctrine
An overlying rights holder is a property owner who pumps groundwater from an aquifer beneath their land for use on that land. In California, overlying rights are correlative among all landowners above a shared aquifer. When the aquifer cannot satisfy all overlying users, each holder is entitled to a proportionate share rather than first-come-first-served priority.
Landowners who pump groundwater and transport it off their property for sale or use elsewhere hold appropriative groundwater rights, which carry lower priority than overlying rights. Overlying users have priority over those who pump for export or commercial sale.
SGMA and Groundwater Sustainability Plans
The Sustainable Groundwater Management Act (SGMA), enacted in 2014 and codified at California Water Code section 10720 et seq., requires local Groundwater Sustainability Agencies (GSAs) in critically overdrafted basins to develop Groundwater Sustainability Plans (GSPs). These plans may restrict pumping, impose fees, and allocate groundwater among users. The California Department of Water Resources oversees SGMA implementation and evaluates GSP compliance.
For property owners and agricultural operators in affected basins, SGMA can materially affect land use. A ranch that has historically relied on unlimited groundwater pumping may face curtailments under a GSP that prioritizes sustainability over individual use. The economic impact of reduced pumping allocations can be significant, particularly for high-water-use crops.
SGMA and Regulatory Takings
Where SGMA-based pumping restrictions substantially reduce the economic value of agricultural land or eliminate a property’s economically viable use, regulatory takings arguments may arise. California’s inverse condemnation doctrine, grounded in Article I, Section 19 of the California Constitution, covers property damaged by government action as well as property formally taken.
Whether a specific SGMA restriction rises to a compensable taking depends on the extent of the economic impact, the property owner’s investment-backed expectations, and other fact-specific factors. For background on how inverse condemnation and eminent domain intersect with property rights in California, see Eminent Domain vs. Inverse Condemnation in California: What’s the Difference.
Water Rights Disputes Between Property Owners
Disputes Over Surface Water
Surface water disputes between neighboring property owners often involve claims that one party is diverting more than their proportionate share, that a diversion is harming a downstream riparian right, or that a prescriptive right has been established through long-term use. These disputes can arise suddenly, for example when a new pump is installed, or can develop gradually over years of contested use.
The factual issues in surface water disputes are often complex. Historical diversion records, gauge data, creek flow measurements, and expert hydrology testimony may all be relevant. The outcome depends heavily on the specific facts of each property’s water history.
Groundwater Interference Claims
Groundwater pumping by one property owner can affect the water table available to neighboring landowners. Where aggressive pumping by one party causes a neighboring well to go dry or reduces yield, a legal dispute may follow.
California courts recognize claims for interference with groundwater rights. The applicable legal standard and available remedies depend on the specific facts, including the aquifer type, the pumping quantities, the relationship between the parties’ wells, and whether the basin is subject to SGMA or a court adjudication.
Adjudicated Groundwater Basins
Some California groundwater basins have been adjudicated by courts, resulting in court judgments allocating pumping rights among all basin users. In an adjudicated basin, a property owner’s right to pump groundwater is defined by the court judgment rather than by general common law principles. The judgment is enforced by a watermaster appointed by the court.
Buying property in an adjudicated basin without understanding the adjudicated allocation can result in a mismatch between a buyer’s expected water supply and what the adjudication actually permits. This is a critical due diligence issue in agricultural real estate transactions.
Regulatory Oversight and Property Owner Rights
State Water Resources Control Board Authority
The SWRCB has broad authority over surface water rights in California. It can issue curtailment orders during droughts, revoke or modify water rights for non-use or waste, and adjudicate disputes between competing claimants. Property owners whose water diversions are curtailed or whose rights are challenged through SWRCB proceedings have procedural rights to participate in those proceedings and to appeal adverse decisions. The SWRCB’s water rights adjudication process is described at the State Water Resources Control Board.
Water Rights and Development Projects
Development projects that require new or expanded water supplies must demonstrate that an adequate water supply is available before local agencies can approve them. California Government Code section 66473.7 and Water Code section 10910 et seq. require that cities and counties prepare water supply assessments before approving significant residential developments.
Where a development project proposes to use groundwater from a basin subject to SGMA, the project’s water supply analysis must address whether the proposed use is consistent with the applicable groundwater sustainability plan. Inadequate water supply documentation is a frequent basis for CEQA challenges to development approvals.
CEQA review often intersects with water supply issues. The CEQA analysis for a project must address whether the project has adequate water supply and how water use affects regional hydrology. The firm’s CEQA law practice is at CEQA Law. A comparison of NEPA and CEQA is at NEPA vs. CEQA: Key Differences for California Property Owners.
Water Quality and Property Contamination
Water quality issues often intersect with water rights and property law. Contamination of an aquifer by an upgradient source can impair a property owner’s ability to use their well, reduce property value, and give rise to regulatory obligations under state environmental law. Phase I and Phase II environmental site assessments address water quality concerns as part of real estate due diligence. An overview of environmental due diligence in California real estate is at Phase I Environmental Site Assessment in California: Risks and Legal Issues.
Water Districts and Property Owner Rights
Water districts in California have authority to impose connection fees, charge for water deliveries, adopt water conservation regulations, and in some cases restrict new connections. Property owners who are denied connection to a district’s water supply, or who face restrictions on their use of district-supplied water, may have administrative appeal rights within the district and judicial remedies if the district exceeds its authority.
Where a water district’s actions affect a property owner’s ability to develop or use their land, property rights arguments may arise alongside administrative law issues. Permit delays caused by water availability concerns are one context where water law and land use law intersect directly. An overview of permit delay issues in California is at California Building Permit Delays: What Property Owners Need to Know.
Water Rights and California Property Transactions
Water rights are property interests that can be bought, sold, and transferred, subject to regulatory requirements. In agricultural and rural property transactions, water rights can constitute a significant portion of the total property value. A ranch sold “with water rights” may carry a substantially different value than the same land without them.
Riparian Rights in Conveyances
When a property with riparian rights is sold, the riparian right generally transfers with the land without a separate assignment. However, if the property has been subdivided and the deed to a particular parcel does not include riparian land, the riparian right may not transfer. Buyers of subdivided properties near water should verify whether their specific parcel retains riparian access.
Appropriative Rights Transfers
Appropriative water rights can be transferred separately from the land they were originally associated with. A water rights transfer typically requires SWRCB approval to change the point of diversion, place of use, or purpose of use. An unapproved transfer or change in use can jeopardize the right.
Buyers of appropriative water rights should investigate the validity and priority date of the right, any conditions or limitations in the permit or license, and whether the right has been exercised continuously. Long periods of non-use can result in forfeiture under California Water Code section 1241.
Due Diligence for Water-Dependent Properties
Properties whose value depends significantly on water access require thorough due diligence. This includes reviewing recorded water rights, checking for SWRCB permit conditions, understanding the relevant basin’s adjudication or SGMA status, reviewing any water service agreements with local districts, and investigating any pending disputes or curtailment actions affecting the water supply.
Environmental conditions affecting water quality are part of this analysis. Real estate transactions involving potentially contaminated water supplies raise additional due diligence issues addressed at Phase I Environmental Site Assessment in California: Risks and Legal Issues. The firm’s real estate law practice is at Real Estate Law.
Property Damage from Water Infrastructure and Public Projects
Public water infrastructure, including canals, reservoirs, flood control channels, and water delivery systems, can cause physical damage to adjacent private property. Where water released or diverted through public infrastructure floods or damages private land, inverse condemnation claims may arise. California’s constitutional provision covers property “damaged” as well as “taken” by government action for public use. An overview of property damage claims arising from public projects is at Property Damage From Public Projects in California: Your Legal Rights.
Property owners adjacent to irrigation districts, flood control channels, and municipal water infrastructure should understand their rights when that infrastructure causes damage to their property. The applicable legal framework differs depending on whether the damage was caused by design of the public improvement, failure to maintain it, or some other cause.
Kassouni Law’s Water Law and Property Rights Practice
Kassouni Law’s water law practice handles legal issues involving water rights, private property ownership, land use, and regulatory disputes in California. The firm represents clients in water rights disputes between neighboring property owners, SGMA compliance matters, and regulatory takings claims. The practice also covers water supply issues in real estate transactions, development approvals, CEQA challenges involving water availability, and property damage claims from water infrastructure. The firm’s water law practice is at Water Law. Its broader environmental law practice is at Environmental Law.
The firm represents private property owners, agricultural operators, and developers exclusively. It has never represented a government agency. Managing attorney Timothy V. Kassouni has over three decades of experience in California property rights and land use law, including matters that intersect with water rights and environmental regulation.
Protect Your California Property Rights in Water Disputes
Kassouni Law represents California property owners in water rights and property-related disputes, including riparian and appropriative water rights matters, SGMA-related regulatory issues, real estate matters involving water interests, and claims involving water infrastructure impacts. If a water rights issue is affecting your property, land use plans, or ownership interests, contact Kassouni Law at 877-770-7379 or visit kassounilaw.com/contact to discuss your situation with our team.
Frequently Asked Questions
1. What is the difference between riparian rights and appropriative water rights in California?
Riparian rights attach to land that borders a natural watercourse. The property owner may make reasonable use of the water flowing past the land. These rights come from land ownership and do not require a permit. Appropriative water rights allow a party to divert water from a surface source for beneficial use, even without owning adjacent land. Post-1914 appropriative diversions require a permit from the State Water Resources Control Board. These rights follow a priority system, giving senior rights holders the first claim during shortages. Both systems coexist in California. Disputes between riparian and appropriative rights holders follow the reasonableness standard under Article X, Section 2 of the California Constitution.
2. How does SGMA affect California property owners who rely on groundwater?
The Sustainable Groundwater Management Act (Cal. Water Code § 10720 et seq.), enacted in 2014, requires local Groundwater Sustainability Agencies to develop plans to achieve sustainable groundwater management in critically overdrafted basins. These plans can restrict the amount of groundwater individual landowners may pump, impose fees, and allocate pumping rights among basin users. For agricultural operators and rural landowners in affected basins, SGMA can materially reduce available water and affect land productivity. Where SGMA restrictions substantially diminish a property’s economic value, regulatory takings arguments may arise, depending on the severity of the restriction and the specific facts of the property and the applicable plan.
3. Can a California property owner lose water rights from non-use?
California law may forfeit appropriative water rights when owners fail to use the water for five years. California Water Code section 1241 creates a rebuttable presumption of abandonment after five or more years of non-use. A rights holder may rebut that presumption by showing the non-use resulted from drought, unavoidable circumstances, or another valid reason. Riparian rights generally do not face the same forfeiture rules. However, California law still requires owners to use those rights reasonably and for beneficial purposes. Property owners who hold appropriative water rights but have not used them recently should evaluate whether their rights remain active.
4. What happens when a neighboring property owner’s groundwater pumping affects my well?
A property owner may have legal claims when a neighboring landowner’s groundwater pumping lowers the water table and reduces an adjacent well’s yield or causes it to go dry. California courts recognize certain claims for interference with water rights, depending on the circumstances. The applicable legal standard depends on several factors. These include whether the basin has been adjudicated, whether SGMA applies, and the relationship between the wells and the underlying aquifer. Remedies may include limits on further pumping, damages for resulting losses, or allocation of available groundwater among affected users. The outcome depends on the specific facts, the basin’s legal status, and the governing law.
5. Do water rights transfer automatically when California property is sold?
The answer depends on the type of water right and the way the property transfers. Riparian rights generally transfer with the riparian land when the owner sells the property. They do not usually require a separate assignment. However, a riparian right may not transfer if the owner subdivides the parcel and the buyer’s lot no longer borders the water source. Appropriative water rights, by contrast, can transfer separately from the land. However, changes to the point of diversion, place of use, or purpose often require approval from the State Water Resources Control Board. An unapproved transfer or unauthorized change in use can put the right at risk. Buyers of California properties with water rights, especially agricultural and rural properties, should investigate the rights’ legal basis and status during due diligence.
