WORST States for Rainwater Harvesting

Though there are no states that completely ban rainwater harvesting in the United States as of 2024, some states have stricter regulations than others. 

One of the main reasons some states have stricter regulations has to do with water rights.  Often, this is closely related to the scarcity of water in the state as well as potential environment impacts rain harvesting would have on its natural waterways and ecosystems. In arid states specifically, there may be concerns about the impact of widespread rainwater harvesting on water availability for other users.

These states have the most strict regulations:

Colorado

Colorado historically had some of the strictest laws against rainwater collection due to its adherence to the Prior Appropriation System for water rights[4]. However, the state has relaxed its stance in recent years:

• In 2009, Colorado decriminalized rainwater collection for non-potable purposes.

• As of 2016, residents are allowed to collect rainwater in two rain barrels with a combined capacity of 110 gallons[3].

• The collected water can only be used on the property where it was collected and for outdoor purposes[3].

Nevada

Nevada also has some restrictions on rainwater harvesting:

• Rainwater collection was illegal in Nevada until 2017.

• Currently, Bill Number 138 allows rainwater to be collected for domestic use, but only for non-potable purposes[2].

Arkansas

Arkansas allows rainwater harvesting but with specific regulations:

• Rainwater can only be used for non-potable purposes.

• Harvesting systems must be designed by an Arkansas-licensed professional engineer.

• Systems must be designed with cross-connection safeguards.

• Systems must comply with the Arkansas Plumbing Code[4].

Illinois

Illinois also has relatively strict regulations on rainwater harvesting:

• Collected rainwater can only be used for non-potable purposes.

• Rainwater harvesting systems must be constructed in accordance with the Illinois Plumbing Code[3].

It's important to note that many states are becoming more supportive of rainwater harvesting as a sustainable practice, with some even offering incentives or rebates for installing collection systems. Always check your local and state regulations before setting up a rainwater harvesting system.