As an affiliate, we may earn a commission from qualifying purchases. We get commissions for purchases made through links on this website from Amazon and other third parties.
As of August 31, 2026, some form of rainwater collection is legal in every U.S. state. There is no statewide rule that completely bans a homeowner from collecting rainwater in every situation.
The important part is what happens after that basic answer. Some states limit how much water you can store, where you can collect it, or how you can use it. Local plumbing, building, health, and water-right rules can add more requirements.
The U.S. Department of Energy notes that rainwater harvesting is handled mainly at the state level and that permits may also be required by state or local government. The National Conference of State Legislatures says most states give residents broad freedom to collect rain, while Colorado and 18 other states place some type of limit on access or use.
States Where Rainwater Collection Is Legal
All 50 states allow rainwater collection in at least some form:
| State | Rainwater Collection Legal? |
|---|---|
| Alabama | Yes |
| Alaska | Yes |
| Arizona | Yes |
| Arkansas | Yes |
| California | Yes |
| Colorado | Yes, with important limits |
| Connecticut | Yes |
| Delaware | Yes |
| Florida | Yes |
| Georgia | Yes |
| Hawaii | Yes |
| Idaho | Yes |
| Illinois | Yes |
| Indiana | Yes |
| Iowa | Yes |
| Kansas | Yes |
| Kentucky | Yes |
| Louisiana | Yes |
| Maine | Yes |
| Maryland | Yes |
| Massachusetts | Yes |
| Michigan | Yes |
| Minnesota | Yes |
| Mississippi | Yes |
| Missouri | Yes |
| Montana | Yes |
| Nebraska | Yes |
| Nevada | Yes |
| New Hampshire | Yes |
| New Jersey | Yes |
| New Mexico | Yes |
| New York | Yes |
| North Carolina | Yes |
| North Dakota | Yes |
| Ohio | Yes |
| Oklahoma | Yes |
| Oregon | Yes |
| Pennsylvania | Yes |
| Rhode Island | Yes |
| South Carolina | Yes |
| South Dakota | Yes |
| Tennessee | Yes |
| Texas | Yes |
| Utah | Yes, with storage and registration rules |
| Vermont | Yes |
| Virginia | Yes |
| Washington | Yes, with conditions |
| West Virginia | Yes |
| Wisconsin | Yes |
| Wyoming | Yes |
"Yes" does not mean every rainwater system is automatically allowed. A simple barrel used to water flowers may face few rules, while a large cistern connected to household plumbing can be regulated much more closely.
Colorado Has Some of the Clearest Collection Limits
Colorado is the state most likely to cause confusion because it historically had strict water-right rules.
Most qualifying homeowners can now collect rooftop rainwater without getting a special water-right permit. However, the standard residential exemption allows:
- No more than two rain barrels.
- No more than 110 gallons of combined storage.
- Collection from the roof of a single-family home or a residential building with four or fewer units.
- Use on the same property where the water was collected.
- Outdoor uses such as watering lawns, gardens, and plants.
Colorado's Division of Water Resources confirms these conditions. A 2025 bill that would have removed the collection limits was postponed indefinitely, so those proposed changes did not take effect.
Some rural properties with qualifying exempt wells may have other collection options under separate Colorado rules.
For a typical homeowner, this means installing several thousand gallons of rooftop storage in Colorado should not be treated the same way as installing two ordinary rain barrels.
Utah Allows Larger Systems but May Require Registration
Utah also has clear statewide limits.
You can collect rainwater without registration when you use no more than two covered storage containers and neither container holds more than 100 gallons.
For larger systems, Utah allows up to 2,500 gallons of total storage, but you must register the rainwater harvesting system with the Utah Division of Water Rights. Registration is free.
The collected water must also be used on the same parcel where it was captured and stored.
For example, two 55-gallon rain barrels would normally fall below the registration threshold. A 1,000-gallon tank would require registration.
California Allows Rooftop Rainwater Harvesting
California specifically exempts rooftop rainwater harvesting from the normal requirement to obtain a water-right permit.
California Water Code Section 10574 allows rainwater collected from rooftops to be stored without obtaining that permit.
That does not remove every other rule. A barrel feeding a garden is very different from a cistern connected to toilets, washing machines, or drinking-water plumbing. Building and plumbing requirements can still apply.
Washington Allows Rooftop Collection Without a Water-Right Permit
Washington's Department of Ecology says a water-right permit is generally not required for rooftop rainwater collection when certain conditions are met.
The water must be collected from an existing structure that has another purpose besides collecting rain, and it must generally be used on the property where it was collected.
Rules become much stricter if you want rainwater to supply a house.
Washington notes that counties differ on whether collected rainwater can serve as a drinking-water source. A homeowner planning a rainwater-only water supply for new construction should check with the county planning and health authorities first.
Oregon Allows Collection From Artificial Impervious Surfaces
Oregon water law exempts collection of precipitation from an artificial impervious surface from the normal water-right permit requirement.
An artificial impervious surface is something water cannot easily soak through, such as a roof or paved surface. Oregon law specifically recognizes collecting and using precipitation from such surfaces.
Oregon also has plumbing requirements for rainwater systems used inside buildings. A simple outdoor barrel therefore has a different regulatory path from a cistern connected to household fixtures.
Texas Strongly Supports Rainwater Harvesting
Texas allows rainwater harvesting and has several state laws that support it.
The Texas Water Development Board provides guidance for systems used for landscaping as well as more complex applications. Texas law also limits the ability of homeowners associations to simply prohibit rainwater harvesting systems.
The rules get more involved if harvested rainwater is connected to a public water system or used indoors for potable purposes.
Guidance on state prohibitions on collecting rainwater helps document jurisdiction-specific guidance for the project.
Potable means water intended to be safe for drinking, cooking, and similar uses.
Texas requires safeguards against cross-connections between certain rainwater systems and the public drinking-water supply. Additional plumbing and approval requirements can apply.
Illinois Allows Rainwater Harvesting but Plumbing Rules Still Matter
Illinois recognizes rainwater harvesting as a form of green infrastructure. State guidance includes rain barrels and cisterns used to capture water for later use.
As in other states, collecting roof runoff for garden irrigation is usually a much simpler issue than routing harvested water into a building.
Indoor systems can fall under state or local plumbing requirements.
Legal Collection Does Not Mean Legal Use for Everything
This is one of the most important distinctions.
Your state may allow you to put a barrel under a downspout, but that does not automatically mean the collected water can be used for:
- Drinking
- Cooking
- Showering
- Washing dishes
- Supplying a toilet
- Connecting to household plumbing
- Connecting to a public water supply
Roof runoff can pick up bird waste, insects, dust, roofing materials, metals, chemicals, and microorganisms.
A screen or ordinary sediment filter does not make that water safe to drink. Neither does a single UV unit, water-quality meter, test strip, or other individual treatment device.
Using harvested rainwater as drinking water should be treated as a complete water-supply project. Collection surfaces, prefiltration, treatment, disinfection, storage, current laboratory testing, maintenance, plumbing protection, and applicable health rules all matter.
Check Local Rules Before Installing a Large System
State law is only one layer.
Counties, cities, water districts, health departments, and building departments may regulate the system even when rainwater harvesting itself is legal.
Local requirements become especially important when you plan to:
- Install a large cistern.
- Bury a tank.
- Connect a pump or pressure system.
- Run rainwater pipes inside the house.
- Connect rainwater plumbing near a public water supply.
- Use rainwater for drinking or other household uses.
- Build a rainwater system as the main water supply for a new home.
A basic garden barrel usually involves fewer issues. A 5,000-gallon household system deserves a check with the local building, plumbing, water, or health authority before construction begins.
Rainwater Collection Laws Can Change
The information here is current as of August 31, 2026.
Water law changes, especially in western states where water rights can affect rainwater collection. Local plumbing codes and allowed uses can also change separately from state collection laws.
Before spending money on a large tank or plumbing system, check the current guidance from your state's water agency and your local building or health department. The Department of Energy's rainwater harvesting tool also provides a state-level starting point, but DOE advises users to verify state and local permit requirements.
Frequently Asked Questions
Is collecting rainwater illegal anywhere in the United States?
No state has a complete statewide ban on all rainwater collection as of August 31, 2026. Some form of collection is legal in every state, but restrictions and allowed uses vary.
What state has the strictest rainwater collection rules?
Colorado has unusually specific limits for ordinary residential rain barrels. Most qualifying homes are limited to two barrels with no more than 110 gallons of combined storage under the standard exemption.
How much rainwater can I legally collect in Utah?
Utah allows up to 2,500 gallons of total storage after registering with the Division of Water Rights. Registration is generally not required for no more than two covered containers when neither holds more than 100 gallons.
Do I need a permit for a rain barrel?
Usually not for a simple residential barrel, but you should check your state and local rules. Larger tanks, plumbing connections, indoor uses, and some special water-right situations can require permits or registration.
Can an HOA stop me from collecting rainwater?
That depends on state law and the HOA rules. Some states, including Texas and Colorado, limit an HOA's ability to prohibit qualifying rainwater systems, although reasonable appearance or placement requirements may still be allowed.
Can I legally drink collected rainwater?
Collection being legal does not automatically make drinking it legal or safe. Potable rainwater systems may be regulated by plumbing, building, and health authorities. Drinking-water use also requires suitable collection, treatment, laboratory testing, and ongoing maintenance.
Can I collect rainwater in a large IBC tote or cistern?
Possibly, but tank size can change which rules apply. Utah, for example, requires registration above its small-container exemption, while Colorado's standard residential rain-barrel allowance has a 110-gallon combined storage limit. Check state and local requirements before installing a large tank.
