Each RBMP must apply to a river basin district (RBD), which is an area of land made up of one or more neighbouring river basins and associated coastal waters – see map at Annex 1.
Cewch rannu'r arwynebedd lleiaf o 1 hectar rhwng un neu ragor o barseli tir, ar yr amod bod pob parsel o leiaf 0.1 hectar.)