Rain-fed zoning

Zoning of the Paris Rain Regulations

The Paris rain zoning regulation, called “ParisPluie”, has been enforceable since March 2018. It aims to manage rainwater as close as possible to where it falls and thus limit its admission to the sewerage system.

Its principle is to cut down in 24 hours, the first millimeters of rains falling on any land or set of land, public or private, provided that its area is eligible for rain zoning regulations. It is referred to as a minimum volume reduction (4, 8, 12 or 16 mm depending on the location). The excess volume is transferred to the sewerage system.

The optimum objective that can of course be sought, corresponds to the total disconnection of rainwater, which means no discharge into the sewerage system regardless of the type of rain up to the decennial rain (48 mm in 4 hours).

The map of the Parisian rain zoning was built according to the rules of hydraulic operation of the sewerage network and the geological characteristics of the basement.

To know the abatement area in which a project is located (minimum target to be achieved), it is the situation of its connection point to the sewerage network that counts (address of the existing connection or to be created).

Specificity of the hatched area: in this area, the additional requirement applies, for any project with a reference area of more than 2 500 m², to regulate the leakage rate to 10 L/s/ha of the discharge of uncut rainwater volumes to the sewerage system, at least until the decennial rain.

Documentation & Mapping:

To access the rules and the Guide d’Accompaniment du ParisPluie, please refer to the following page: Plan Paris Rain

Cartography of the rain-fed zoning of Paris