Is it illegal to collect rainwater?
No, it is not illegal to collect rainwater in the United Kingdom. This is one of the most common misconceptions about rainwater harvesting, and the straightforward answer is that homeowners, businesses, and community organisations are perfectly within their rights to capture and store rainwater for legitimate uses.
The Legal Position on Rainwater Collection
In the UK, there is no law that prohibits the collection of rainwater from rooftops and other impermeable surfaces. Unlike some countries where water rights are tightly controlled — particularly in arid regions where water scarcity has led to strict government regulation — the UK operates under a relatively permissive legal framework. The Environment Agency has explicitly stated that domestic rainwater harvesting does not require a licence or permit.
Common Misconceptions
The confusion about the legality of rainwater collection often stems from several sources. First, some people confuse water abstraction licences — which are required for extracting water from rivers, lakes, or groundwater — with rainwater harvesting. These are entirely different activities governed by different regulations. Second, there are persistent myths circulating online that the government plans to tax or ban rainwater harvesting, none of which have any basis in current legislation.
Permitted Uses for Collected Rainwater
Collected rainwater can be used for a wide range of purposes including gardening and plant watering, washing cars and outdoor equipment, flushing toilets, laundry (with appropriate filtration), and in some cases, for irrigation of agricultural crops. For indoor non-potable uses, you should ensure your system is properly installed and complies with local building regulations, particularly regarding cross-connection prevention to avoid contamination of the mains water supply.
When You Might Need Permission
While collecting rainwater itself is not illegal, there are circumstances where additional permissions may be needed. If you live in a listed building or a conservation area, installing external rainwater harvesting equipment such as tanks may require planning permission. Large-scale agricultural or commercial systems that collect significant volumes of water may need to notify the Environment Agency, particularly if they involve diverting water from natural watercourses. Some water companies offer rebates or incentives for installing rainwater harvesting systems, and these may come with technical requirements.
Building Regulations Compliance
If you are connecting a rainwater harvesting system to your internal plumbing — for example, to supply toilets or a washing machine — the work must comply with Building Regulations Part G (Sanitation, Hot Water Safety and Water Efficiency) and Part H (Drainage and Waste Disposal). These regulations ensure that rainwater systems are installed safely and do not pose a health risk to occupants. Key requirements include proper pipe labelling to distinguish rainwater pipes from mains water pipes, appropriate backflow prevention devices, and filtration systems that meet British Standard BS 8515.
Conclusion
Rainwater harvesting is a legal, environmentally beneficial practice that is actively encouraged by the UK government and environmental agencies. With the right system in place, you can reduce your water bills, decrease demand on the mains water supply, and help mitigate localised flooding — all while staying firmly on the right side of the law.