Rainwater harvesting has developed a lot in the last few years, especially in remote areas of the city. However, this practice remains more or less marginal due to a lack of knowledge about the standards that apply. Thus, we have elaborated this article to share with you the operating mode, as well as the regulations to know about rainwater harvesting. They will be very useful, especially if you run a restaurant.

Rainwater harvesting through the roof

In order to effectively collect the rainwater that runs off your roof, it is recommended that:

• • Your roof is sloped to limit the impurities and organic matter that accumulate on a flat roof.

• • Your roof should be sloped to limit the impurities and organic matter that accumulate on a flat roof. You should prefer slate or tile roofing to avoid possible contamination of the water by synthetic materials.

Furthermore, you should know that with more roof surfaces projected on the ground, you will be able to collect important quantities of water in your cistern via the gutters.

Good to know about rainwater storage in a cistern

In order to avoid the risk of overflowing onto your roof, we advise you to opt for an underground concrete cistern. Moreover, since rainwater tends to be slightly acidic, storing it in a concrete cistern will help it mineralize. However, you should know that installing an underground cistern requires some work, often requiring a high budget. However, it is always advisable to install it during the earthworks in order to save on the cost of the work.

However, if the option of burying your tank is not possible, don’t be discouraged, as you can always have an open-air polyester tank installed. However, keep in mind that an open-air tank is only recommended for occasional and moderate use. That said, for your garden maintenance, cleaning, toilets as well as housekeeping.

Using filters to improve water quality

There are three main stages of filtration:

1. 1. Placement of a leaf filter (primary filter) before the water enters your tank. This pre-filter is a simple sponge filter in an inspection chamber. It is generally used to collect tree leaves and large impurities. It also prevents small animals from falling into the tank.
   2. Filters of at least 20 microns at the pump outlet retain fine particles to perfect the water for the toilet. An additional 1 to 9 microns filter will be necessary to ensure that the water can be used for washing and cleaning without damaging your plumbing.
   3. For the rainwater to become potable, you need to add to that:

• • A microfiltration system of less than 1 micron, through a ceramic or activated carbon filter, will remove all impurities from the water.

• • Or a reverse osmosis system, through a trickle filtration through a membrane, so that the water is both drinkable and low mineralized.

What the law says about rainwater harvesting

According to the law, you are free to use and dispose of the rainwater that falls on your property. However, it is important for you to know that the use of rainwater must only be for “non-food and non-corporeal” use according to the regulations. Thus, you are not allowed to cook food for your restaurant with reclaimed rainwater.

In addition, the regulations require those who use rainwater harvesting systems to maintain them regularly. This includes cleaning the filters and the bottom of the tank with a high-pressure cleaner. Last but not least, you have to declare the installation of a rainwater harvesting system to your local city hall. Indeed, the law states that if you discharge the rainwater into the sewerage system, you should be billed for it.

Sound off in the comments section below and tell us what you want to read next and if you want to read more about collecting rainwater.