Since the establishment of the dam about 20 years ago, 5 aquatic communities have colonised the dam. Although some of the communities are not as species rich as communities in the closest comparable permanent wetland - the Okavango Delta - this is a remarkable biological diversity. Reedbeds, sedge communities, floating mats and floating-leaved vegetation make up the "true" wetland communities, which are permanently inundated. The seasonal changes in water level support a rich community of fringe vegetation, which is comprised of wetland as well as terrestrial species. Naturally adapted to seasonal changes in water level, none of the aquatic and wetland communities are expected to be negatively affected by a gradual rise in water level, provided that certain recommendations are followed.