Commentaries: Art. 4

The cantons shall ensure that a regional drainage plan (RDP) is drawn up to guarantee appropriate waters protection in a limited, hydrologically-related area in which waters protection measures of the communes must be coordinated.
The RDP determines in particular:
1. the locations of wastewater treatment plants and areas which are to be joined to them;
2. which and to what extent surface waters are suitable for the discharge of wastewater, particularly that arising from precipitation;
3. the wastewater treatment plants for which requirements in respect of discharge of wastewater must be stricter or supplemented.
In drawing up the RDP, the authorities shall take account of spatial requirements of waters, flood protection and measures for waters protection other than wastewater treatment.
The RDP is mandatory for planning and establishing of waters protection measures in communes.
It shall be accessible to the public.