Rainwater Harvesting Laws by State: The Complete 2026 Guide
Every year, thousands of people want to collect rainwater for their homestead, garden, or off-grid water supply — and run into conflicting information online. Some sources claim it’s illegal everywhere. Others say it’s always fine. Neither is accurate.
The truth: no US state bans rainwater harvesting, but the rules vary dramatically. Colorado limits you to two 55-gallon barrels. Texas protects your right to collect unlimited rainwater by law. Utah requires free registration above 200 gallons. Oregon allows it — but only from rooftops.
We’ve researched the actual statutes, state agency guidance, and official sources for all 50 states. Here’s what the law actually says.
The Short Answer: What You Need to Know First
No state prohibits rainwater harvesting. Federal law has no restrictions — this is entirely state and locally administered.
Two states cap residential collection: Colorado (110 gallons maximum) and Utah (200 gallons without registration; 2,500 gallons with free registration).
Most states are unrestricted at the state level — but local codes, county rules, and HOAs may still apply regardless of what the state says.
For indoor use, most states require plumbing permits and mandate “non-potable” labeling. Outdoor irrigation is almost universally unrestricted.
States With No Restrictions (Collect as Much as You Want)
These 27 states have no quantity caps, no registration requirements, and no state-level permit requirements for typical residential collection. Local codes may still apply.
| State | Notes | Financial Incentives |
|---|---|---|
| Alabama | No restrictions; extension services promote rain barrels | None |
| Alaska | No restrictions; common rural water source | None |
| Delaware | No restrictions; state sponsors rain barrel programs | None |
| Florida | No restrictions; multiple counties encourage rain barrels | Orlando ($200 max); St. Petersburg ($50); Manatee County (discounted kits) |
| Idaho | No restrictions; collection from rooftop/impervious surfaces | None |
| Indiana | No restrictions; DNR encourages rain barrels | Greater Elkhart County ($50/barrel, max 2) |
| Iowa | No restrictions; permits only above 25,000 gal/24 hrs (agricultural threshold) | None |
| Kentucky | No restrictions; systems under 10,000 gal/day require no permit | Fayette County community project grants |
| Maine | No restrictions; Portland actively encourages rain barrels | None |
| Maryland | No restrictions; actively promoted by state government | Gaithersburg ($250); Montgomery County (up to $7,500); Prince George’s County ($6,000–$20,000) |
| Massachusetts | No restrictions; state water standards recommend rain barrels | None |
| Michigan | No restrictions; state documents promote rain barrel use | Washtenaw County utility credit |
| Minnesota | No restrictions for domestic use (permit threshold is 10,000 gal/day) | Northfield ($20); Rochester ($10/barrel); South St. Paul ($50) |
| Mississippi | No restrictions | None |
| Missouri | No restrictions; DNR promotes harvesting | Christian County ($300 max) |
| Montana | No restrictions | None |
| New Hampshire | No restrictions; state provides fact sheets | None |
| New Jersey | No restrictions for residential; permits only above 100,000 gal/day | Somerville, Bridgewater area (up to $200) |
| New Mexico | No restrictions; rooftop collection doesn’t affect senior water rights | Albuquerque ($150); Santa Fe ($50/barrel or $0.25/gal) |
| North Dakota | No restrictions for domestic/livestock use under 12.5 acre-feet/year (NDCC § 61-04-02) | None |
| Oklahoma | No restrictions; state actively promotes harvesting | None |
| Pennsylvania | No restrictions; government promotes through funded programs | West Chester Borough stormwater rebates |
| South Dakota | No restrictions under 25,920 gal/day (water rights permit threshold) | None |
| Tennessee | No restrictions; permits only above 50,000 gal/day | Chattanooga reimbursement program |
| Vermont | No restrictions; state promotes rain barrels and cisterns | None |
| West Virginia | No restrictions; state provides detailed guidance | None |
| Wyoming | No restrictions for domestic use | None |
States With Active Incentive Programs
These states have passed legislation explicitly authorizing rainwater harvesting, or offer meaningful financial incentives beyond standard municipal rebates.
Texas — Most Homeowner-Friendly State
Legal status: Explicitly protected by law. No volume caps for residential use.
Texas House Bill 3391 (2011) explicitly protects “the right to harvest rain water.” New state buildings must incorporate rainwater harvesting. Sales tax is exempt on all harvesting equipment, materials, and installation labor — an exemption that has been on the books since 2001.
Over 27 municipal programs offer rebates ranging from $25 to $5,000. Austin offers up to $5,000; San Antonio up to $2,000 at $1–$2 per gallon of storage capacity.
Key statute: HB 3391 (2011); Texas Tax Code § 151.355
California — Legal with Property Tax Benefit
Legal status: No volume cap for residential rooftop collection.
The Rainwater Capture Act of 2012 (AB 1750) made rooftop collection exempt from water rights permits. Proposition 72 (2018) added a property tax exclusion for rainwater capture systems installed between January 1, 2019 and January 1, 2029 — the system won’t trigger a property tax reassessment.
Local rebates vary from $25 to $2,000+ depending on municipality.
Key statute: AB 1750 (2012); California Prop. 72 (2018)
Virginia — Tax Credits Available
Legal status: No restrictions on collection.
Virginia offers income tax credits for installation and a cost-share program through Soil and Water Conservation Districts of $4 per gallon of system capacity, up to $20,000.
Key statute: Senate Bill 1416
Arizona — Legal with Tax Credits
Legal status: No quantity limits; no permit required for residential use.
Multiple state and local programs promote collection actively. Prescott offers $0.50/gal; Tucson up to $2,000. A 75% agricultural use tax credit applies for qualifying systems.
Rhode Island — 10% Tax Credit
Legal status: Legal; plumbing permit required for installation.
A 10% tax credit on installation costs is available, up to $1,000 (House Bill 7070). Systems must comply with Rhode Island Plumbing Code § 1303.
Key statute: RI Plumbing Code § 1303; HB 7070
States With Volume Limits
Colorado — Most Restrictive State
Legal limit: Maximum 110 gallons total (two 55-gallon barrels maximum) per household.
Colorado’s strict limit is a product of its prior appropriation water law — senior water rights holders downstream have legal claims on precipitation that falls in the watershed. House Bill 16-1005, signed in 2016, legalized residential collection within this limit.
Rules:
– Two 55-gallon barrels maximum, no exceptions
– Rooftop downspout collection only
– Outdoor, non-potable use only (lawn, garden, plants)
– Cannot be used indoors or for drinking
– No permit required if you stay within these limits
Homeowners with certain well permits may qualify for additional capacity under separate provisions.
Key statute: C.R.S. § 37-96.5-103; HB 16-1005 (2016)
Official source: Colorado Division of Water Resources
Utah — Legal with Registration
Legal limit: 200 gallons without registration; 2,500 gallons with free registration.
Without registering: Two covered containers, neither exceeding 100 gallons (200 gallons total maximum).
With free online registration through the Utah Division of Water Rights: Up to 2,500 gallons of aboveground storage. Collection and use must occur on the same parcel.
Key statute: Utah Code § 73-3-1.5; Senate Bill 32 (2010)
Registration: waterrights.utah.gov
Nevada — Legal for Single-Family Homes
Legal status: Legal for single-family residential rooftop collection; no stated volume cap (characterized as “de minimis”).
Assembly Bill 138 (2017) explicitly legalized collection from the rooftop of a single-family dwelling for non-potable domestic uses (pet/livestock watering, car washing, toilet flushing, evaporative cooling). Multi-family or commercial collection is not authorized under this law.
Before AB 138, all collection technically required a water right — the law was technically ambiguous even for rain barrels until 2017.
Key statute: Nevada AB 138 (2017)
States Requiring Permits or Code Compliance
These states allow rainwater harvesting but require permits, plumbing code compliance, or restrict use to non-potable applications.
Arkansas
Simple rain barrels used solely for drip or subsurface garden irrigation are exempt from permit requirements. Larger systems connected to plumbing must be designed by a licensed professional engineer, limited to non-potable uses, and include cross-connection safeguards.
Incentive: 50% tax credit for agricultural impoundments 20+ acres.
Key statute: Arkansas Code § 17-38-201
Connecticut
Legal but plumbing permits are required for installation. Outlets must be labeled “CAUTION: NONPOTABLE WATER – DO NOT DRINK.” No shutoff valve on overflow pipe allowed. Approved materials only.
Georgia
Legal for non-potable use — vehicle washing, landscape irrigation, livestock watering, toilet flushing. Permit requirements vary by locality.
Incentive: Rainharvest System Tax Rebate up to $2,500 (HB 1069, 2010).
Key statute: Georgia Plumbing Code Chapter 15
Illinois
Legal for non-potable use. Exterior catchment systems for outdoor drip irrigation under 360 gallons do not require a plumbing permit. Larger systems must comply with Illinois Plumbing Code.
Incentive: Springfield: rebates up to $25 for barrels 50+ gallons.
Kansas
Domestic use is exempt from water permit requirements — covers household use, livestock watering, watering up to 2 acres of lawn/gardens. Commercial/agricultural use requires a permit from the Kansas Department of Agriculture.
Key statute: KSA 82a-703a
Nebraska
Legal; Section P2912 of the Nebraska Residential Code requires: debris excluder, first-flush diversion, tank outlet no less than 4 inches from tank bottom.
New York
Legal; residential collection unrestricted. Plumbing permits required above 100,000 gal/day. Systems must include debris excluder, first-flush diverter, and filtration requirements for non-potable indoor use.
North Carolina
Legal; no quantity cap. Multiple cost-sharing programs: New Hanover County (75% reimbursement), Raleigh (90% reimbursement).
Key legislation: House Bill 609 (2011); Senate Bill 163 (2014)
Ohio
Non-potable use unrestricted. Potable use systems subject to Ohio Administrative Code Rule 3701-28-12 (effective January 1, 2020). Multiple county workshops and Franklin County $50 rebates.
Oregon
Legal for rooftop collection only without a permit. Collecting from ground-level surfaces or natural channels requires a water rights permit. This distinction matters: you can collect from your roof — you cannot intercept rainwater running across the ground.
Key statute: Oregon House Bill 2080 (2009)
Incentive: Portland: up to $120 in stormwater fee savings.
Rhode Island
Plumbing permit required. Non-potable labeling mandatory. Systems under 5,000 gallons do not require a separate water permit.
Incentive: 10% tax credit on installation, up to $1,000.
South Carolina
Legal; Section 1303 of South Carolina Plumbing Code governs debris exclusion, first-flush diversion, and filtration for non-potable indoor use.
Washington State
Legal with conditions. No permit required if: (1) water is used on the same property where collected, (2) collection is from existing structures that also serve another primary purpose. Indoor non-potable systems must be designed by a registered professional engineer. Potable use as primary water supply requires county approval — many counties prohibit it.
Official source: Washington Dept. of Ecology
Wisconsin
No permit required for aboveground systems not connected to buildings and not used for potable purposes. Permits required for systems above 100,000 gallons per 30-day period.
Incentives: River Falls ($30); Verona ($10/barrel, 4 max); Waukesha ($20/barrel, 2 max).
Full 50-State Quick Reference Table
| State | Status | Volume Limit | Potable? | Permit? |
|---|---|---|---|---|
| Alabama | No restrictions | None | Not addressed | No |
| Alaska | No restrictions | None | Common rural use | No |
| Arizona | Encouraged | None | Allowed | No |
| Arkansas | Conditional | None (simple barrels exempt) | No | Yes (engineered systems) |
| California | Encouraged + tax benefit | None | Per local rules | No (rooftop) |
| Colorado | Volume-capped | 110 gal max | No | No (within limits) |
| Connecticut | Permit required | None stated | No | Yes |
| Delaware | No restrictions | None | Not addressed | No |
| Florida | No restrictions | None | Not addressed | No |
| Georgia | Non-potable only | None | No | Varies locally |
| Hawaii | Encouraged | 360 gal outdoor (permit-free) | Allowed | No (under 360 gal outdoor) |
| Idaho | No restrictions | None | Not addressed | No |
| Illinois | Non-potable only | 360 gal outdoor (permit-free) | No | No (simple barrels) |
| Indiana | No restrictions | None | Not addressed | No |
| Iowa | No restrictions | None | Not addressed | No |
| Kansas | Domestic use exempt | None (domestic) | Household use allowed | No (domestic) |
| Kentucky | No restrictions | None | Not addressed | No |
| Louisiana | No restrictions | None | Not addressed | No (cover required) |
| Maine | No restrictions | None | Not addressed | No |
| Maryland | No restrictions | None | Not addressed | No |
| Massachusetts | No restrictions | None | Not addressed | No |
| Michigan | No restrictions | None | Not addressed | No |
| Minnesota | No restrictions | None (domestic) | Not addressed | No |
| Mississippi | No restrictions | None | Not addressed | No |
| Missouri | No restrictions | None | Not addressed | No |
| Montana | No restrictions | None | Not addressed | No |
| Nebraska | Code compliance | None | Non-potable code requirements | No |
| Nevada | Single-family rooftop | No stated cap | No — non-potable | No |
| New Hampshire | No restrictions | None | Not addressed | No |
| New Jersey | No restrictions | None | Not addressed | No |
| New Mexico | No restrictions | None | Not addressed | No |
| New York | Code compliance | None (residential) | Non-potable (code) | No (permits above 100K gal/day) |
| North Carolina | No restrictions | None | Not addressed | No |
| North Dakota | No restrictions | None (domestic) | Not addressed | No |
| Ohio | Encouraged | None | Non-potable unrestricted | No (non-potable) |
| Oklahoma | No restrictions | None | Not addressed | No |
| Oregon | Rooftop only | None (rooftop) | Not addressed | No (rooftop) |
| Pennsylvania | No restrictions | None | Not addressed | No |
| Rhode Island | Permit required | None stated | Non-potable only | Yes |
| South Carolina | Code compliance | None | Non-potable (code) | No |
| South Dakota | No restrictions | None (domestic) | Not addressed | No |
| Tennessee | No restrictions | None | Not addressed | No |
| Texas | Explicitly protected | None | Potable has requirements | No (residential) |
| Utah | Registration above 200 gal | 100 gal/container unregistered; 2,500 gal registered | No — same-parcel only | No (free online registration) |
| Vermont | No restrictions | None | Not addressed | No |
| Virginia | No restrictions | None | Not addressed | No |
| Washington | Conditions apply | None stated | County approval required | No (non-potable) |
| West Virginia | No restrictions | None | Not addressed | No |
| Wisconsin | Code for connected systems | None (simple outdoor barrels) | Permits for potable/connected | No (simple outdoor barrels) |
| Wyoming | No restrictions | None | Not addressed | No |
| D.C. | Encouraged + required for commercial | None | Not addressed | No |
Key Facts to Know Before You Start
1. Local rules override state rules. Over 3,200 counties and 19,500 municipalities can impose additional restrictions. If you’re in an HOA, read your CC&Rs — HOAs can prohibit rain collection regardless of state law.
2. For drinking water, always filter and treat. Even in states where potable collection is technically allowed, rainwater collected from rooftops picks up bird droppings, metal particles from roofing materials, and atmospheric contaminants. It should be treated through a proper filtration system before drinking.
3. “Non-potable” restrictions are common. Many states allow unlimited outdoor collection but restrict indoor use to toilets, laundry, and irrigation — not drinking or cooking. Check your state’s specific rules for indoor use.
4. California’s Prop. 72 property tax exclusion expires January 1, 2029 unless renewed by the legislature. Systems installed before that date retain the exclusion for the duration of the system’s life.
5. Colorado is not improving. The 110-gallon cap is codified in statute and there’s no pending legislation to change it. If you’re in Colorado and want a serious rainwater system, the practical path is to move water rights law forward politically — or collect only what’s legal and supplement with other sources.
Recommended Equipment
If you’re setting up a rainwater collection system, the most common approach is a food-grade polyethylene storage tank connected to a downspout diverter. For potable use, pair storage with filtration.
For simple barrel setups, search Amazon for rain barrel diverter kits. For larger cistern systems capable of holding hundreds or thousands of gallons, IBC tote tanks (275–330 gallon) are the most cost-effective solution for homesteaders.
For off-grid potable water from rainwater, look at a gravity-fed ceramic filter system capable of removing bacteria, protozoa, and heavy metals.
Official Sources
- Colorado: Division of Water Resources | HB 16-1005
- Utah: Division of Water Rights — Registration
- Texas: Texas Water Development Board
- California: AB 1750 — Rainwater Capture Act of 2012
- Oregon: Building Codes Division — Rainwater Smart Guide
- Nevada: AB 138 (2017)
- Washington: Dept. of Ecology
- EPA Water Reuse State Summaries: epa.gov/waterreuse
Last updated April 2026. Laws change — always verify your state’s current rules with the relevant state agency before installing a system.
