Under the Water Framework Directive (WFD), the European Union obliged all member states to protect all their surface water and restore it to a good condition by 2015. For administrative reasons, they must subdivide their surface water into water bodies and define water body types. The Directive proposes minimum sizes for water bodies. Like some other member states, Germany has interpreted this to mean that small rivers, often called headwaters, and small ponds and lakes need not be identified and delineated as a water body and therefore do not fall under the protection system of the WFD. This paper analyses whether the German interpretation and implementation can be considered correct, given that small surface water elements are not unimportant. In Germany, they account for two-thirds of the overall length of rivers. Like the little twigs of a tree, small rivers have a decisive impact on the whole river basin.