Rainwater collection, which is simply the practice of collecting or storing rainwater from a catchment area, is becoming increasingly popular in areas of the world facing water shortages, particularly in developed countries. Rainwater collection has been practiced for centuries, and thankfully is becoming more widely accepted. 

Rainwater collected from rooftops and other structures such as tanks, cisterns, ponds, and barrels, can be significantly beneficial for agricultural, industrial, recreational, and residential uses. This water can also be used as an alternative to traditional potable or drinking water sources, if treated properly.

In certain parts of the world, the legalities of rainwater collection vary depending on the region and sometimes include state-specific regulations and requirements. As this is a critical aspect to consider before attempting to capture and use water collected through rainfall, it is important to understand the different legalities surrounding the various states.

Understanding the Legality of Rainwater Collection by State

Having an understanding of the law in regards to rainwater collection is paramount, as this can be used as an additional water source by individuals looking to supplement their water supply, preserve the environment and conserve natural resources. Before harvesting rainwater, one should always be aware of any legal ramifications and obtain the necessary permits.


In Alabama, rainwater collection is allowed, with the exception of run-off water from agricultural land used for irrigating crops. Since the state is in a constant state of drought, harvesting rainwater is generally both praised and encouraged within the state legislature.


In Alaska, rainwater collection is also allowed, however, rainwater capture or catchment from roofs, gutters or other available structures is regulated. The Alaska Division of Environmental Conservation (DEC) has established regulations for the harvesting of rainwater and indicates that such water may be used for non-potable purposes without the need for a permit. All harvested rainwater should not be used for drinking or cooking, unless approved by the state health department.


In Arizona, the ownership of collected rainwater falls under the ‘Appurtenant Rights of Capture’ law which states that property owners can capture and use the rainwater falling on their property as long as they don’t adversely affect other water sources. The state encourages citizens to participate in rainwater collection and provides helpful resources on the implementation of such projects.


In California, the law allows residents to collect rainwater on their own property as long as the collection is properly managed and does not divert or interfere with any streams or water sources. However, the quantity of rainwater collected should not exceed two acre-feet or 10,000 gallons per year. Any collected water used for agricultural purposes must be registered with the Department of Water Resources and may require additional permits from the State Water Resources Control Board.


In Colorado, the law states that the ownership of collected rainwater lies with the water commissioner as long as the catchment does not adversely affect other water sources. However, if the rainwater is caught in a cistern, barrel or tank on the property of a user, the collected water is owned by the person or entity capturing it. Additionally, the user must apply for a water right permit with the state water court and abide by various regulations.

Overall, understanding the legalities of rainwater collection by state can be a tricky endeavor, as each state enforces different rules and regulations. It is important to research the applicable regulations in the area where one plans to collect rainwater, as this can have significant implications on rainwater usage, especially if the collected water will be used as a potable or drinking water source. Despite the complexities, rainwater collection can be immensely beneficial, so it is important to know the rules and regulations in order to ensure the safe and proper use of this precious resource.