Collecting rainwater, which is considered one of the components of off-grid water systems, is an easy way to cut water bills, support local water conservation, and even create an emergency supply—but is it legal? While no federal laws regulate rainwater harvesting, individual states set their own rules, ranging from full support with incentives to strict restrictions.
For example, states like Texas and Arizona encourage rainwater collection with tax incentives, while others, like Colorado, have strict limits on how much you can store. Understanding your state’s laws is crucial before setting up a system.
In this guide, we’ll break down the legal landscape of rainwater harvesting, explain why some states regulate it, and help you navigate the requirements in your area.
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What Is Rainwater Harvesting?
Rainwater harvesting is the process of collecting and storing rainwater for later use, typically by directing it from a home’s gutters into rain barrels or storage tanks (cisterns). Many homeowners use harvested rainwater for watering gardens, landscaping, or even flushing toilets, helping to reduce their reliance on municipal water.
A basic rainwater collection system includes:
- A capture system – Usually your home’s gutters and downspouts.
- A filter – To remove debris like leaves and dirt.
- A storage tank – Such as a rain barrel or underground cistern.
Some homeowners filter and boil harvested rainwater for drinking, but this isn’t always recommended. Untreated rainwater may contain bacteria, pollutants, or chemicals from roofing materials. If you plan to use rainwater for drinking, you’ll need a proper filtration and purification system to ensure it’s safe.
Most states allow rainwater collection for non-potable water uses like watering plants, washing outdoor surfaces, and irrigation. If you want to use it for drinking or household use, check local regulations, as some states have stricter rules on treatment and usage.
Deciding whether to collect rainwater? Get insight into the process with this video tutorial from Andrew Millison:
Are There Regulations on Rainwater Harvesting?
Yes, rainwater harvesting is regulated differently in each state. Some states encourage collection with tax incentives, while others have strict permit requirements or use restrictions.
Here are the key factors that influence rainwater harvesting laws:
- Permit Requirements – Some states require homeowners to get a permit before installing a rainwater harvesting system. This may include submitting system plans, paying fees, and ensuring compliance with safety standards.
- Water Rights – In states with strict water rights laws, rainwater is considered part of the shared water supply. Homeowners may face limitations on how much they can collect.
- Water Quality Standards – Many states have guidelines on filtering and treating harvested rainwater, especially if it’s used for drinking or household purposes.
- Tax Incentives – Certain states, like Texas and Arizona, offer rebates or tax breaks for homeowners who install rainwater collection systems. These incentives can help offset installation costs.
- Use Restrictions – Some states limit rainwater use to non-potable purposes like irrigation, landscaping, and toilet flushing.
- Mandatory Systems – In arid states, such as New Mexico, some new buildings are required to include rainwater harvesting systems to help with water conservation.
Before setting up a system, check your state and local laws to ensure compliance and take advantage of available incentives.
What Affects State Rainwater Harvesting Laws?
State regulations on rainwater harvesting vary based on several key factors:
- Climate – States with heavy rainfall, like Oregon or Florida, tend to have fewer restrictions, while arid states (e.g., Arizona, New Mexico) often encourage rainwater collection to combat drought.
- Water Scarcity – Areas facing water shortages are more likely to promote harvesting as a conservation strategy. Some states even offer tax incentives for installing collection systems.
- Water Rights Laws – States with strict water rights systems (like Colorado) may have limits on how much rainwater homeowners can collect to ensure enough reaches rivers, lakes, and other users downstream.
- Environmental Policies – States that prioritize sustainability often support rainwater harvesting, sometimes with grants or rebates for homeowners who install systems.
- Local Regulations – City and county governments may have additional rules, restrictions, or incentives, so always check local ordinances before setting up a system.
Before installing a rainwater collection system, research both state and local laws to ensure compliance and take advantage of any available benefits.
State Regulations on Residential Rainwater Collection
Laws on rainwater collection vary by state. To find out the rules in your area, use the interactive map and table below. You can:
- Hover over your state to see its rainwater harvesting regulations.
- Search for your state in the table for specific laws and restrictions.
- Flip through table pages to compare regulations across different states.
Before setting up a rainwater collection system, check your state and local guidelines to ensure compliance and take advantage of any available incentives.
This site receives compensation from the companies featured in this listing, which may impact where and how products appear. This listing doesn’t feature all companies, products, or offers that may be available.
| State | Regulation Y/N | Encouraged Y/N | Description |
| Alabama | No | No | Water collection is considered a private property right with no regulations. |
| Alaska | No | No | Rainwater harvesting is the primary means of water collection for many Alaskan homeowners and is unregulated. |
| Arizona | No | No | In Arizona, there are bills that allow towns to generate funds for harvesting systems. |
| Arkansas | Yes | No | According to Arkansas code § 17-38-201, homeowners can harvest rainwater as long as it’s non-potable, the harvesting system is installed by a licensed plumber, is designed with appropriate coss-connection safeguards, and is up to plumbing code. |
| California | Yes | No | The Rainwater Capture Act of 2012 allows homeowners, property owners, government agencies, and business owners to harvest rainwater as long as it’s for approved purposes. |
| Colorado | Yes | No | House Bill 16-1005 states that homeowners are allowed to collect a maximum of two rain barrels with a combined capacity of 110 gallons. That water may also only be used outdoors. |
| Connecticut | No | Yes | No regulation exists on rainwater collection, and the state encourages its homeowners to do so. |
| Delaware | No | Yes | No regulations exist, and there are state-sponsored incentive programs. |
| Florida | No | Yes | Florida possesses no rainwater harvesting restrictions and has incentive and rebate programs. |
| Georgia | Yes | No | Rainwater is tightly regulated by the Department of Natural Resources and must only be applied for outdoor use. |
| Hawaii | No | Yes | Rainwater harvesting is highly encouraged by Hawaii’s local government. |
| Idaho | Yes | No | Homeowners are allowed to capture and use rainwater as long as it does not re-enter natural waterways. |
| Illinois | Yes | No | According to the Plumbing-Rainwater Systems Bill SB0038, rainwater harvesting systems must be up to state plumbing code, and the water must be used for non-potable purposes. |
| Indiana | No | Yes | There are no restrictions on rainwater harvesting, and it’s encouraged by the state. |
| Iowa | No | No | No rainwater harvesting regulations exist in the state at this time. |
| Kansas | No | No | Rainwater harvesting is legal in Kansas for domestic use. |
| Kentucky | No | No | No rainwater harvesting regulations exist in the state at this time. |
| Louisiana | Yes | No | Rainwater harvesting is legal in Louisiana as long as the tank holding or capturing the rainwater is properly covered and sealed. |
| Maine | No | No | No rainwater harvesting regulations exist in the state at this time. |
| Maryland | No | Partially | Maryland does not currently have any regulations on rainwater harvesting, with some counties offering incentive programs. |
| Massachusetts | No | Yes | Massachusetts does not have any restrictions on rainwater harvesting and encourages its residents to do so. |
| Michigan | No | Yes | It’s legal to harvest rainwater in Michigan, with the state encouraging its residents to do so. |
| Minnesota | No | Yes | Minnesota allows and encourages its residents to harvest rainwater. |
| Mississippi | No | No | No rainwater harvesting regulations exist in the state at this time. |
| Missouri | No | Yes | There are no restrictions or regulations on water harvesting in Missouri, and the state encourages its homeowners to do so. |
| Montana | No | Yes | The state of Montana does not regulate or restrict rainwater harvesting, actively encouraging its residents to do so. |
| Nebraska | No | Yes | There are no regulations or restrictions on rainwater harvesting in Nebraska, with several universities offering incentives. |
| Nevada | Yes | No | Rainwater collection was illegal in Nevada until 2017. However, Bill Number 138 now states that rainwater can be collected for domestic use as long as it’s non-potable. |
| New Hampshire | No | Yes | New Hampshire encourages its residents to collect rainwater and places no restrictions or regulations on its harvesting. |
| New Jersey | No | Yes | New Jersey Assembly Bill 2442 offers rebate programs for homeowners that use specific harvesting methods. |
| New Mexico | No | Yes | New Mexico places no regulations or restrictions on rainwater harvesting and encourages its residents to do so. |
| New York | No | Yes | New York does not restrict or regulate rainwater harvesting. |
| North Carolina | Yes | No | Rainwater harvesting is allowed with specific regulations, such as the water being used for non-potable purposes, pipes for rainwater harvesting being labeled as purple, and collection tanks being marked as non-potable water. |
| North Dakota | No | Yes | North Dakota does not restrict or regulate rainwater harvesting and encourages its citizens to do so. |
| Ohio | Yes | No | According to Ohio Rev. Code §3701.344, rainwater can be harvested for potable and non-potable purposes for any household or group of fewer than 25 people, with restrictions on what materials can be used in its collection. |
| Oklahoma | No | No | There are no restrictions or regulations on harvesting rainwater in Oklahoma at this time. |
| Oregon | Yes | No | Rainwater collection is legal, often requiring a permit and restricting homeowners to outdoor systems (such as through rooftop collection). |
| Pennsylvania | No | Yes | Harvesting rainwater in Pennsylvania has no restrictions or regulations and is encouraged. |
| Rhode Island | No | Yes | State Bill 7070 provides tax incentives for up to 10% of the cost of the installation of cisterns. |
| South Carolina | No | Yes | Rainwater harvesting has no restrictions or regulations in South Carolina, with the state encouraging its practice. |
| South Dakota | No | No | No rainwater harvesting regulations exist in the state at this time. |
| Tennessee | No | No | Tennessee does not have any laws regulating or restricting the harvesting of rainwater. |
| Texas | Yes | Yes | Texas has multiple regulations on harvesting rainwater, such as requiring written notice to be given to the municipality. But, the state also offers various incentives like no tax on rain barrels. |
| Utah | Yes | No | Utah has strict regulations on rainwater harvesting. Specifically, you must register your harvesting system, use the water on the land it was harvested on, and collect no more than 2,500 gallons of rainwater. Unregistered systems may collect no more than 100 gallons. |
| Vermont | No | No | No rainwater harvesting regulations exist in the state at this time. |
| Virginia | Yes | Yes | Virginia encourages its residents to harvest rainwater, with Senate Bill 1416 offering tax credits to those with rainwater collection and harvesting systems. There are regulations as well, such as rainwater only being used for non-potable purposes, and the first 4 inches of water must be flushed via a diverter. |
| Washington | Yes | No | It’s legal to collect rainwater in Washington, but there are regulations. You must use the water on the property it was collected on, the system for collecting water must serve another purpose (such as irrigation), and each county has different rules on the potability of rainwater. |
| West Virginia | No | No | No rainwater harvesting regulations exist in the state at this time. |
| Wisconsin | No | No | No rainwater harvesting regulations exist in the state at this time. |
| Wyoming | No | No | No rainwater harvesting regulations exist in the state at this time. |
Closing Thoughts
Harvesting rainwater is a great way to reduce your water bill while helping the environment by aiding in groundwater recharge. While no state outright bans rainwater harvesting, many have strict regulations or permit requirements, while others actively encourage it with tax incentives and rebates.
Because there are no federal rainwater laws, it’s up to each state—and sometimes local governments—to set the rules. Before installing a system, check your state’s regulations to ensure compliance and take advantage of any incentives that can help offset costs.
By following the rules and using a well-designed system, you can responsibly harvest rainwater, reduce your reliance on municipal water, and support long-term environmental conservation efforts—all while saving money.
Frequently Asked Questions
Yes, collecting rainwater is legal in California, but it must comply with state regulations. The Rainwater Capture Act of 2012 allows homeowners, businesses, and government entities to install and use rainwater collection systems, such as rain barrels and cisterns.
However, these systems must follow State Water Resources Board requirements, which ensure water quality and safe use.
In California, collected rainwater is typically limited to non-potable (not for drinking) purposes like irrigation, landscaping, and toilet flushing. If you plan to install a system, check local ordinances, as some cities may have additional rules.
Some states regulate rainwater collection to prevent disruptions to natural water cycles. When rain falls, it replenishes underground aquifers, lakes, and rivers. If too much rainwater is diverted, it could reduce available water for agriculture, wildlife, and other users.
Additionally, water rights laws play a role. In Western states with strict water rights systems, such as Colorado, water is legally allocated to users downstream, meaning even rainwater is considered part of this system. This is why certain states limit how much homeowners can collect or require permits.
Some states regulate rainwater collection with restrictions, permits, or guidelines. Examples include:
- Colorado – Homeowners can collect up to 110 gallons of rainwater, but only for outdoor use.
- Arkansas & Georgia – Require harvested rainwater to meet state plumbing codes.
- Idaho & Illinois – Restrict collection for potable (drinking) use unless systems meet strict treatment standards.
- Louisiana – Requires homeowners to follow specific construction guidelines for rainwater harvesting systems.
- California – Allows collection but requires compliance with state water board regulations.
While no state completely bans rainwater harvesting, some make it easier than others. Always check with local authorities before setting up a system to ensure compliance.
