Definitions and classification of waterways

Waterways can be divided into three classes:
1. natural channels, i.e. rivers, or parts of rivers, the flow of which is not
modified – the river channel may be improved by river training works;
2. canalized rivers, the flow of which is to a greater or smaller degree

controlled by engineering works;
3. canals, entirely artificial waterways whose water is obtained by diversion
from rivers, by pumping or from reservoirs.