Map visualisation service (WMS) of the dataset: Restricted area of the PPRN flooding by overflow of the Charente river of the municipality of Romegoux in Charente-Maritime

For natural PPRs, the environmental code defines two categories of zones (L562-1):
risk-exposed areas and areas that are not directly exposed to risks but where measures may be foreseen to avoid exacerbating the risk.

Depending on the hazard level, each area is subject to an enforceable settlement.
Regulations generally distinguish three types of zones:

1- “Building Prohibition Zones”, so-called “Red Zones”, when the hazard level is strong and the general rule is the construction ban;

2- “prescription zones”, known as “blue zones”, where the hazard level is average and projects are subject to requirements adapted to the type of issue;

3- areas not directly exposed to risks but where constructions, structures, development or agricultural, forestry, artisanal, commercial or industrial activities could exacerbate risks or cause new ones subject to prohibitions or requirements (cf. Article L562-1 of the Environmental Code).
The latter category applies only to natural PPRs.