1.0

Used to model river integrity, river types and delineate new sub-quaternary catchments (planning units) and free-flowing rivers. The river types are used by NFEPA to represent river ecosystem types across the country.

The GIS layer of origin is the 2007 1:500 000 rivers data layer available from DWA website. CSIR subsequently used this layer to add information. First, the geomorphological zonation from DWA was added to this layer. Next 97 coastal rivers were added from the Chief Directorate Surveys and Mapping’s (CDSM) 1:50 000 rivers GIS layer, and their associated geomorphological zonation coded manually using desktop information available from the SRTM DEM. Added rivers were based on missing South African estuaries along the coast line. River condition was determined by using DWAF’s 1999 Present Ecological State (Kleynhans, 2000) as the base GIS layer for quaternary catchment mainstem rivers. Condition was modelled for all other 1:500 000 tributaries (i.e. rivers that nest within quaternary catchments) based on the National Land Cover 2000; available provincial updates from KwaZulu-Natal, Gauteng, Northern Cape and Mpumalanga; and transformed waterbodies from the inland water bodies GIS layer from CDSM. This process used % natural land cover within 100m, 500m & sub-quaternary catchment in combination with % erosion within 500m of the tributary (from the dongas, gullies and sheet erosion land cover classes). Updated Ecological Reserve Determination data, sub-national Present Ecological State (PES) assessments, EcoStatus data and River

Health Data were used to guide discussions at expert review workshops and subsequently update the river condition. River condition was used to inform the selection of rivers as FEPAs and the subsequent FEPA map categories. For example, only river ecosystems in good condition (A or B ecological category) were chosen as FEPAs because these rivers provide the best examples of representative examples of South Africa’s freshwater ecosystems and associated biodiversity.

River ecosystem types consist of distinct combinations of: Level 1 ecoregions (30 categories; Kleynhans et al. 2005) flow descriptions from Surveys and Mapping that describes Perennial and Seasonal rivers as “Permanent” and Ephemeral rivers as “Not permanent” (2 categories), slope categories based on geomorphological zonation work by Rowntree and Wadeson (1999), defining 4 categories: Mountain streams, Upper foothills, lower foothills and lowland rivers. At regional review workshops, experts reviewed these river types and changes were made where necessary, with reasons, updating the river ecosystem types to 223. River reaches satisfying all of the following requirements were selected as free-flowing rivers: (1) Permanent or seasonally flowing; Intact (AB rivers); (2) No instream dam throughout its length; (The Upper Vaal and Upper Marico rivers were special cases where the long stretch of river flowing freely from source to dam was considered free-flowing ) (3) Length = 50 km for inland rivers, with no size threshold for coastal rivers. River types and river condition were used to identify reaches qualifying under these criteria. The 1:50 000 farm dams GIS layer (DLA-CDSM 2005) was used to identify instream dams. To account for spatial inaccuracies between the 1:500 000 rivers and the 1:50 000 dams, the dams were buffered by 50 m. Any buffered dam that intersected a river was then assumed to be an instream dam. Certain limitations of the input data include: (1) farm dams built after 2005 not included; (2) weir data were not included; and (3) water transfer 3 schemes were not explicitly included in the analyses (however, for main rivers they were accommodated implicitly in the assessment of river condition). The buffering technique used may also disqualify some rivers which are indeed free-flowing since off-stream dams within 50 m of a river will be classified as instream dams. Free-flowing rivers were expertly reviewed and updated. There are 62 free-flowing rivers in South Africa, of which only 25 are longer than 100 km, 19 of the 62 free-flowing rivers were identified as flagship free-flowing rivers at the final national review workshop.

Available documentation:

DLA-CDSM, 2005-2007. Department of Land Affairs – Chief Directorate: Surveys and Mapping. 1:50 000 inland waterbodies and rivers.

Kleynhans, C.J. 2000. Desktop estimates of the ecological importance and sensitivity categories (EISC), default ecological management classes (DEMC), present ecological status categories (PESC), present attainable ecological management classes (present AEMC), and best attainable ecological management class (best AEMC) for quaternary catchments in South Africa. DWAF report, Institute for Water Quality Studies, Pretoria, South Africa.

Kleynhans, C.J., Thirion, C. and Moolman, J. (2005). A Level I Ecoregion classification system for South Africa, Lesotho and Swaziland. Resource Quality Services, Department of Water Affairs and Forestry, Private Bag X313, Pretoria, 0001, South Africa.

Nel, J.L., Murray, K.M., Maherry, A.M., Petersen, C.P., Roux, D.J., Driver, A., Hill, L., Van Deventer, H., Funke, N., Swartz, E.R., Smith-Adao, L.B., Mbona, N., Downsborough, L. and Nienaber, S. (2011). Technical Report for the National Freshwater Ecosystem Priority Areas project. WRC Report No. K5/1801. Rowntree, K.M., Wadeson, R.A., 1999. A Hierarchical Geomorphological Model for the Classification of Selected South African Rivers. Water Research Commission Report No 497/1/99, Water Research

SANS 1878

FGDC-STD-001-1998