Understanding Subterranean Hydrology in the Delineation of Wetlands : an Ephemeral Hillslope Wetland on Basement Granite in South Africa

Abstract

Wetlands are multi-disciplinary ecosystems defined and classified in many different ways across the world, due to their high variability in hydrological conditions, location, size and human influence. In South Africa the only legislative definition of a wetland is held by the National Water Act 36 of 1998, which was derived from the United States Fish and Wildlife Service (USFWS) Classification System for Wetlands and Deepwater Habitats in the USA, by Cowardin et al. (1979). This Act introduced the first legislation in South Africa directly addressing wetlands, and a manual for wetland delineation was only published in 2005 by the then Department of Water Affairs (DWA). Before the late 1990’s environmental legislation was not very specific on the identification or development of these ecosystems, resulting in their destruction by development. Today still, wetland indicators, as specified by DWA 2005, are often missed in temporary systems during dry periods, and development commences on these wetlands. Not only do these developments cause harm or destroy these ecosystems, but cause major post-development problems such as contamination through surface water-groundwater interaction and seepage of shallow subsurface water though building foundations.