Definition: Rivers, reservoirs

Category: Regional statistics

It is not always clear whether rivers are part of the inland water or not. Outside the areas once affected by glaciation rivers may have a larger water surface than lakes. Since the rivers in most cases are narrow, only a small proportion of a commune or a region will be affected. Thus it is not so important whether rivers are exempted from the surface area or not. Man-made lakes and lakes regulated at a dam may have water levels shifting very much up and down depending on the need to store or use water for hydroelectric purposes. The area of such reservoirs should be defined at the maximum filling. Reservoirs can also include artificial fish-breeding ponds, if such are defined separately.
Eurostat, "Empfehlungen zur Festlegung eines einheitlichen Verfahrens für die Berechnung der Fläche von Gebietseinheiten - Ausgabe 1999; Recommendations for a harmonised definition of calculation of surface area of territorial units, 1999 edition; Recommandations pour une définition harmonisée du calcul de la superficie des unités territoriales - Édition 1999", Office for Official Publications of the European Communities, Luxembourg, 1999, p.15