Table 8. Ecological status categories (from Kleynhans 1999). Category                                 Description A Unmodified, natural B Largely natural with few modifications; a small change in natural habitats and biota may have taken place, but the ecosystem functions are essentially unchanged C Moderately modified; a loss and change of natural habitat and biota have occurred, but the basic ecosystem functions are still predominantly unchanged D Largely modified; a large loss of natural habitat, biota, and basic ecosystem functions has occurred E Extensive loss of natural habitat, biota, and basic ecosystem functions F Modifications have reached a critical level, and the lotic system has been modified completely, with an almost complete loss of natural habitat and biota. In the worst instances, the basic ecosystem functions have been destroyed, and the changes are irreversible.