Rainwater recovery

Verified 24 May 2023 - Legal and Administrative Information Directorate (Prime Minister)

Want to know if you can recover rainwater for your personal use? We are taking stock of the regulations.

This is the water collected downstream of the inaccessible roofs (where the water descends).

The rainwater collected is not drinkable because it is chemically contaminated (pesticides in the rain, metals or asbestos present on the roof). For this reason, collected water can be used for the interior or exterior of your home, but only under certain conditions.

Rainwater recovery and storage requires the installation of an above-ground or buried tank (the buried tank generally has a greater storage capacity).

This equipment can be bought in particular in DIY shops.

The equipment can be settled by yourself or by a company of your choice.

Your equipment should preferably be settled near a roof or gutters.

When using rainwater inside your home, the access taps must be clearly identified.

These valves must be capable of being locked (blocked). Their opening must be provided with a specific tool, which is not permanently attached to the valve.


It is forbidden to settle a tap that distributes rainwater in a room where there are taps that distribute drinking water (except basements, basements and other ancillary rooms such as a garage for example).

In addition, a signaling plate bearing the indication Non-potable water with an explicit pictogram must be displayed next to each point of rainwater draw-off and toilet supplied by rainwater.

This sign is available in DIY stores.

Yes, some municipalities offer subsidies to buy the necessary equipment.

To find out if such help exists in your municipality, you should contact the city council.

Who shall I contact

Rainwater can be collected for your personal use, excluding food consumption.

Indoor use

Inside your home, you can use rainwater only for the following cases:

  • Fill the toilet flush
  • Wash floors
  • Washing linen, provided that a water treatment device is used, in particular for disinfection


it is forbidden to use inside your home rainwater that has run off on a roof containing asbestos cement or lead.

Outdoor use

You can use rainwater freely outside your home, especially to water your garden or clean your car.

No, he's strictly prohibited to consume rainwater.

So you must not drink it. You should also not use it to cook or wash dishes.

Please note

You can consume the produce grown in your garden if you water it with rainwater recovered through your recovery system.

Yes, if your equipment is connected to the collective sewerage system (i.e. sewer). This is the case if you use rainwater collected inside your home.

Your return must be on open paper.

It shall contain the following information:

  • Identification of the vessel concerned
  • Assessment of the volumes of water used inside your home

Your declaration must be filed or sent to the city hall in charge of the sanitation.

Who shall I contact

If you use rainwater inside your home, you must maintain your equipment by:

  • You need to check every 6 months the cleanliness of your equipment and the presence of the nameplate non-potable water. You should also check for connections between the human consumption network and the rainwater distribution network.
  • You have to do every year (yourself or a company of your choice) cleaning the filters and emptying, cleaning and disinfecting the storage tank. Valves and bleed valves should also be checked (or have checked).


Do not apply anti-freeze to the storage tank.

You are also required to maintain a sanitary maintenance log of your equipment. This document should contain the following information:

  • Name and address of the company in charge of the maintenance if you do not carry out the maintenance yourself
  • Detailed plan of your rainwater recovery equipment
  • Commissioning sheet
  • Dates of audits and maintenance performed
  • Monthly index survey of rainwater volume assessment systems used inside your home connected to the wastewater collection system

If your accommodation is rented, you must inform your tenant of the operation of your rainwater recovery equipment.

If you sell your home, you must inform the buyer, by any means, of the existence of this equipment.

A technical agent of the drinking water network of your town hall can make a control of your equipment.

If the agent detects an anomaly that could potentially contaminate the public drinking water system, he or she will ask you to make improvements to your facility. If you refuse to take these measures, the mayor may request the closure of your equipment, possibly with the help of the police.

In addition, in case of contamination of the public drinking water supply system, you risk 3 years imprisonment and €45,000 of fine.

Who can help me?

Find who can answer your questions in your region