Commentaries: Art. 43

In order that the bed load budget in a watercourse is not unfavourably influenced by extraction of gravel, sand or other materials (Art. 44 para. 2 let. c WPA), the authorities must ensure that:
1. the quantity of bed load extracted from the watercourse does not exceed the natural supply;
2. the extraction does not in the long term lead to a subsidence of the bottom outside the extraction perimeter;
3. the extraction does not render impossible the maintenance and re-establishment of inventoried floodplains;
4. the extraction does not lead to a substantial change in the particle size distribution of the bottom material outside the extraction perimeter.
Extraction according to paragraph 1 should not lead to turbidity that may impair fishing waters.