Commentaries: Art. 17

The cantons shall take account of the hazard areas and the risks in their structural and land-use plans and in their other activities with a spatial impact. They shall in particular ensure in hazard areas that:
1. risks are limited when zoning, upzoning and rezoning and when granting permission for the construction of buildings and installations;
2. unacceptable risks are reduced by rezoning, downzoning and dezoning or by moving buildings and installations at risk to safer locations.
They shall designate buffer zones in the structural and land-use plans in which natural events may be allowed to occur in order to protect other areas. In buffer zones, the risk shall be reduced by limiting the form and extent of use.