Is It Illegal to Collect Rainwater in California

Rainwater collection, a practice as old as agriculture itself, has seen a resurgence in recent years, driven by environmental concerns and sustainability efforts. In California, a state often plagued by drought and water scarcity, the legality of rainwater harvesting is a topic of considerable interest. This article delves into the current legal framework surrounding rainwater collection in California, aiming to provide a comprehensive understanding for residents and environmental enthusiasts.

Rainwater Collection

Before delving into the legal aspects, it’s essential to understand what rainwater collection entails. Essentially, it involves capturing and storing rainwater from rooftops, land surfaces, or rock catchments. This stored water can be used for various purposes, including irrigation, livestock, and, with proper treatment, even for drinking.

Legal Framework in California

As of my last update in April 2023, collecting rainwater in California is legal. The state encourages this practice, recognizing its benefits in reducing runoff, improving water conservation, and lessening the demand on the municipal water supply. This stance is a significant shift from past perceptions, where rainwater was often viewed more as a collective resource managed by state and local authorities.

The Rainwater Capture Act of 2012

A landmark moment in the legal status of rainwater harvesting in California came with the Rainwater Capture Act of 2012. This legislation explicitly states that residential, commercial, and governmental properties can install, maintain, and operate rainwater capture systems for specified purposes without it being considered a water diversion. In other words, this act legitimizes the practice of rainwater collection and use, provided it adheres to certain guidelines and local regulations.

Local Regulations and Considerations

While the state law permits rainwater harvesting, local ordinances and building codes might have specific requirements or restrictions. For instance, some areas may have guidelines on the type of materials used in rainwater catchment systems or stipulate that systems meet certain health and safety standards, especially if the water is to be used for potable purposes.

Environmental and Safety Standards

Adhering to environmental and safety standards is crucial when setting up a rainwater collection system. This includes ensuring that collected water does not become a breeding ground for mosquitoes and other pests. Moreover, if rainwater is to be used for drinking, it must be properly filtered and treated to meet health standards, as rooftop runoff can contain pollutants.

Incentives and Rebates

California, in its push towards sustainability, often offers incentives and rebates for rainwater harvesting systems. These can include discounts on rain barrels or rebates for installing larger cisterns. These programs, typically managed by local water authorities or environmental agencies, aim to encourage more residents and businesses to adopt rainwater collection practices.

The Impact on Water Rights

It’s important to note that rainwater collection in California does not infringe upon established water rights. The state’s water rights system, based on a complex blend of riparian and appropriative rights, remains unaffected by individual rainwater collection practices, as long as they adhere to the guidelines set forth in the Rainwater Capture Act.

Best Practices for Rainwater Collection

For those interested in rainwater harvesting, it’s advisable to follow best practices:

  • Use appropriate materials: Ensure that materials used for collecting and storing water are suitable and safe.
  • Regular maintenance: Keep your collection system clean to prevent contamination and blockages.
  • Stay informed: Keep abreast of any changes in local regulations or state laws regarding rainwater harvesting.


In conclusion, collecting rainwater in California is not only legal but also encouraged. It is a practical and sustainable way to conserve water, especially in a state that frequently faces drought conditions. By understanding the legal framework, adhering to local regulations, and implementing best practices, Californians can effectively and responsibly harvest rainwater, contributing to the state’s broader environmental conservation efforts.