Groundwater rights and aquifer law in the United States are set almost entirely at the state level, and the rules for pumping water from beneath your property vary sharply depending on which doctrine your state follows. Some states let you pump without limit. Others require a permit, cap your annual withdrawal, and can revoke your right if you don’t use it. Federal law fills a few specific gaps — contamination liability, injection wells, interstate aquifers, tribal and federal reserved rights — but the day-to-day rules come from your state and, often, a local management district. Because an aquifer doesn’t stop at your property line, the law has to balance what you can do on your land against what your neighbors can do on theirs.
Which Doctrine Controls Your Right to Pump
Five doctrines govern groundwater withdrawals, plus a public trust overlay in a small number of states. Which one applies depends on where the well sits, and many states have modified or blended these rules over time.
Absolute Ownership (Rule of Capture)
Under the rule of capture, you own whatever water you can physically pump from beneath your property, regardless of the effect on a neighbor’s well. If your pumping drains the aquifer under adjacent land, the neighbor’s only option is to drill deeper. About a dozen states still follow some version of this rule, though most have added exceptions for malicious or wasteful pumping. In areas with heavy agricultural demand, the doctrine tends to produce a race to the bottom.
Reasonable Use
The reasonable use doctrine lets you withdraw groundwater for any beneficial purpose on the overlying property without liability for harm to neighbors. The critical word is “on.” Transporting water off the property for sale or distant use generally isn’t protected if it interferes with local users. Most eastern states follow some version of this rule.
Correlative Rights
Correlative rights treat everyone above a shared aquifer as co-owners of the supply. Each landowner gets a reasonable share proportional to their overlying acreage, and during shortages everyone cuts back rather than one user draining the rest. Courts or state agencies allocate the shares when users disagree. The approach tends to produce more equitable outcomes during drought and more litigation the rest of the time, because “reasonable share” is inherently arguable.
The Restatement Approach
The Restatement (Second) of Torts focuses on whether a withdrawal causes unreasonable harm rather than on where the water gets used. A landowner is liable if pumping significantly lowers the water table and the harm outweighs the benefit of the use. Courts weigh the purpose of the use, the effect on other users, and whether the pumping exceeds a proportionate share of the available supply.
Prior Appropriation
Most western states apply prior appropriation to groundwater. The first person to put water to beneficial use holds a senior right that takes priority over everyone later in time. You establish your priority date by obtaining a state permit, and during shortage, senior rights fill completely before junior rights get anything. The system protects long-term investments in agriculture and industry, but in over-appropriated basins there may be no water left to appropriate.
The Public Trust Overlay
A small but growing number of states apply the public trust doctrine to groundwater, treating the resource as something the state holds for current and future generations. Hawaii’s courts have applied this to all water resources. Courts in a few other states have extended trust protections to groundwater when its extraction damages connected surface waters. Where it applies, the doctrine gives state agencies a legal basis to deny new well permits or reallocate existing ones.
Whether You Need a Permit
Household use rarely triggers full permitting. Most states exempt domestic wells from the appropriation process as long as daily pumping stays below a set threshold. In the western states alone, at least 16 maintain some form of domestic exemption. Typical caps run between 1,000 and 15,000 gallons per day, and a few states define the exemption by pump capacity, such as 35 gallons per minute, rather than total volume.
The exemption usually covers drinking water, cooking, bathing, and a small garden or lawn. It does not cover commercial crop irrigation, livestock watering beyond a small number of animals, or industrial use. If your planned use exceeds the domestic threshold or involves selling water off-site, you need a full appropriation permit. Even exempt wells typically require a construction permit for safety and sanitary standards, so check with your state’s water agency before hiring a driller.
Larger uses — large-scale irrigation, industrial processing, municipal supply, commercial livestock — go through the full process. Expect to provide the geographic coordinates of the proposed well, a site map showing distances to property boundaries and existing wells, the planned pumping rate in gallons per minute, the intended use, and the estimated annual volume. Most states require a licensed well driller to submit technical specifications covering well depth, casing materials, and the geologic formations the well will penetrate.
After you file the application and pay the fee, the state agency reviews it against regional management plans and available aquifer capacity. In prior appropriation states, that review includes verifying unappropriated water actually exists in the basin. Most states then open a public comment period, advertised in local media, giving neighbors and other stakeholders a chance to object. A protest triggers an administrative hearing before a state official or judge.
Final approval produces a permit or certificate of appropriation that gets recorded with the county and attaches to the property title. The timeline runs from several months to more than a year in contested basins. Once permitted, you’ll typically need to install a meter and report annual usage to keep the right.
Local Groundwater Management Districts
Many states have created localized management bodies with direct authority over extraction within their boundaries. They go by different names — Groundwater Management Districts, Groundwater Conservation Districts, water management authorities — but the function is the same: prevent individual pumping decisions from destroying a shared resource.
Districts set well-spacing requirements that dictate minimum distances between wells and from property lines. They impose annual production limits tied to acreage or historical use, and can mandate temporary pumping reductions during drought or when monitoring shows the aquifer dropping faster than expected. They monitor water quality, require metering and annual reports, and regulate the plugging of abandoned wells so surface contaminants don’t drain into the aquifer.
Violations can result in administrative fines or revocation of the pumping permit itself. Losing a permit means losing the legal right to pump, and reinstating it is far harder than staying current with the reporting requirements.
Losing a Right You Don’t Use
In most prior appropriation states, a water right is not permanent. Stop using your allocation for the statutory period — typically between four and seven consecutive years — and the state can declare the right forfeited. New Mexico triggers forfeiture proceedings after four years of non-use; Utah uses a seven-year threshold. The principle is consistent across states: rights exist to put water to beneficial use, and idle rights can be reclaimed.
Most states provide notice before forfeiture becomes final, giving the rights holder a chance to resume use or show a valid excuse. Common exemptions include land enrolled in federal conservation programs, water rights held under state-approved conservation plans, and periods when the owner is on active military duty.
Abandonment works differently. Forfeiture turns on a fixed period of non-use regardless of intent. Abandonment requires proof that the rights holder intended to give up the right, which is harder for a state to establish. Both end the right; they just get there by different paths.
Water Rights in a Property Sale
In most states, groundwater rights are appurtenant to the land, meaning they transfer automatically when the property sells unless the deed explicitly reserves or severs them. That is where real estate transactions get dangerous for an inattentive buyer. A seller can carve out the water rights and keep them, leaving you with acreage but no legal right to pump the aquifer beneath it. In some states, water rights have been severed and sold separately for decades, so the person legally pumping water from under your property may not be you.
Before buying rural land, especially in western states where water rights carry significant independent value, confirm the rights are still attached to the title. Read the deed for reservations and exceptions. Verify any existing permits are current and haven’t been forfeited through non-use. If the property sits within a groundwater management district, contact the district about permit status and transfer requirements. Administrative fees for processing an ownership change on a water right typically run from a few hundred to a couple thousand dollars.
Federal Rules That Reach Private Wells and Aquifers
The federal Safe Drinking Water Act does not regulate private domestic wells. The statute only covers “public water systems” — defined as systems serving at least 15 connections or 25 people — leaving private well owners responsible for their own water quality.1Office of the Law Revision Counsel. 42 USC 300f – Definitions The EPA confirms that most state governments don’t regulate private well water quality either.2U.S. Environmental Protection Agency. Private Drinking Water Wells
If you rely on a private well, testing is on you. There is no federal requirement for regular testing, no mandated treatment standard, and no agency that will notify you if contamination reaches the water. The EPA recommends annual testing for bacteria and nitrates at minimum, with additional testing for chemicals if you live near agricultural operations, industrial sites, or old landfills. Many county health departments offer low-cost testing, and private labs can run more comprehensive panels for a few hundred dollars.
Contamination coming from someone else is a different story. If you own property above an aquifer contaminated by an off-site source, the federal Superfund law (CERCLA) generally protects you from cleanup liability as long as you didn’t cause or contribute to the contamination. The EPA’s Contaminated Aquifer Policy, first issued in 1995, says the agency will not require cleanup costs from a landowner whose property sits above a contaminated aquifer if the contamination came from off-site.3U.S. Environmental Protection Agency. Contiguous Property Owners CERCLA amendments in 2002 clarified that the “reasonable steps” required of a contiguous property owner do not include conducting groundwater investigations or installing remediation systems.
Buyers of already-contaminated property can also qualify for CERCLA’s “bona fide prospective purchaser” defense, which shields buyers who acquire property after contamination occurred, as long as they conducted appropriate environmental due diligence before the purchase and did not impede any cleanup.4Office of the Law Revision Counsel. 42 USC 9601 – Definitions You knew about the contamination, or should have. You bought the property anyway. You cooperate with any cleanup. What you didn’t do is cause the problem.
Waste disposal facilities face a separate layer of federal oversight. Under the Resource Conservation and Recovery Act, certain facilities must install groundwater monitoring well networks, conduct semiannual sampling, and follow a detection monitoring program for the active life of the facility plus 30 years after closure.5eCFR. 40 CFR Part 257 Subpart B – Ground-Water Monitoring and Corrective Action If monitoring detects contamination above background levels, the facility must notify the state within 14 days and establish an assessment program within 90 days.
Anyone injecting water underground — for aquifer storage and recovery, for example — falls under the EPA’s Underground Injection Control program, which prohibits any injection activity that could move contaminants into underground sources of drinking water.6eCFR. 40 CFR Part 144 – Underground Injection Control Program Most such wells are rule-authorized Class V injection wells, meaning they can operate without an individual permit as long as the operator submits inventory information to the EPA before construction and the project doesn’t threaten drinking water aquifers. An individual permit becomes necessary when the injected water could introduce contaminants, and permits for Class V wells last up to 10 years.
Federal Reserved Rights, Tribal Rights, and Interstate Aquifers
When the federal government sets aside land for a specific purpose, such as a national monument, military reservation, or national forest, it implicitly reserves enough water to fulfill that purpose, including groundwater. The Supreme Court established this in Cappaert v. United States, holding that the government can protect its reserved water from later diversion “whether the diversion is of surface or groundwater.”7Justia. Cappaert v. United States, 426 U.S. 128 (1976) The amount reserved is limited to what’s necessary for the primary purpose; the government can’t claim unlimited water for later, secondary uses.
Tribal water rights reach further. Under the Winters doctrine, established in 1908, Native American reservations hold implied water rights dating back to the creation of the reservation, often giving tribal claims seniority over virtually every other user in the basin.8Justia. Winters v. United States, 207 U.S. 564 (1908) Whether Winters extends to groundwater is contested. Arizona courts have held that reserved rights include groundwater when necessary to accomplish the reservation’s purpose; Wyoming courts have rejected that extension. Where tribal groundwater claims are recognized, a senior priority date can limit or eliminate the pumping rights of non-tribal users who arrived later.
When an aquifer crosses state lines, management becomes a federal issue. The primary tool is the interstate compact, a binding agreement between states, authorized under the Constitution’s Compact Clause, that allocates shared water resources.9Constitution Annotated. ArtI.S10.C3.3.1 Overview of Compact Clause Compacts set extraction limits for each state and typically create a commission to oversee compliance.
When compacts fail or don’t exist, states can sue each other directly in the Supreme Court, which holds original and exclusive jurisdiction over disputes between states.10Office of the Law Revision Counsel. 28 USC 1251 – Original Jurisdiction The Court applies the equitable apportionment doctrine, weighing historical use, economic dependence, conservation efforts, and the physical characteristics of the water source to divide the resource. The Ogallala Aquifer, which underlies parts of eight states from South Dakota to Texas, is being pumped faster than it recharges in many areas, making it effectively a nonrenewable resource in its central and southern reaches.11Climate.gov. National Climate Assessment: Great Plains’ Ogallala Aquifer Drying Out
Subsidence Liability
Excessive pumping doesn’t just lower the water table. It can cause the land surface itself to sink permanently. When water is pulled from fine-grained sediments, the pore spaces that held the water collapse, compacting the soil and reducing the aquifer’s storage capacity for good. The USGS estimates that more than 17,000 square miles across 45 states have been affected by subsidence, and over 80 percent of that damage traces to groundwater pumping.12U.S. Geological Survey. Land Subsidence
The damage shows up as cracked foundations, broken pipelines, surface fissures, and increased flood risk in areas that have dropped below their original elevation. The legal exposure matters because subsidence caused by one user’s pumping can damage neighboring properties, creating potential liability under negligence or nuisance theories even in states that otherwise follow permissive doctrines like the rule of capture. In the worst-affected areas, management districts have imposed mandatory pumping reductions specifically to halt ongoing subsidence.