Abstract
Horizontal fragmentation, from a public-values perspective, is a quite well-documented phenomenon in international (water) law. However, the literature does not provide any insight into vertical or substantive fragmentation, i.e. differences in the protection of public values at the various institutional levels. This article assesses whether there is substantive fragmentation in water law at the international, the European, the sub-regional (Danube River Basin), and the Dutch domestic level. To this end, first a working definition of the concept of ‘public water values’ will be formulated. Subsequently, this article will draw conclusions regarding the degree of substantive fragmentation in water law across the institutional levels mentioned, based on an in-depth analysis of relevant sources of water law. The article will not present an exhaustive overview of public water values, but elaborates on a number of core values in water law.