Hydrological data and modelling

National Data Portals

Department of Water and Sanitation (DWS) – Surface Water (Data, Dams, Floods and Flows) The primary national portal for surface water data in South Africa, providing access to streamflow records, flood data, dam information, and hydrological station networks managed by DWS.

National Integrated Water Information System (NIWIS) An integrated web-based platform providing access to a wide range of water resource data including surface water, groundwater, water quality, and dam levels across South Africa.

Mzansi Amanzi A monthly outlook of water in South Africa, providing near real-time information on surface water extent and dam storage volume derived from satellite imagery.

Water Resources of South Africa, 2012 Study (WR2012) The most comprehensive national water resources assessment for South Africa, providing long-term rainfall, streamflow, and water use data at the quaternary catchment scale — an essential reference dataset for hydrological modelling.

Global Runoff Data Centre (GRDC) An international repository of streamflow and river discharge data covering stations worldwide, including southern Africa.

SWAT Modelling Datasets (WRC Project C2019-2020-00089)

A national input database for the Soil and Water Assessment Tool (SWAT) is being developed by Dr Jay le Roux at the University of the Free State, with WRC funding. The project collates multiple geo-spatial datasets at a national scale for use as baseline inputs to run ArcSWAT for any catchment in South Africa. The following datasets are available through the WRO:

• Digital Elevation Model – 90 x 90 m (SRTM, hydrologically improved) — includes bordering catchment areas for the Orange, Molopo, and Limpopo Rivers.

• Digital Elevation Model – 30 x 30 m (SRTM) — not yet hydrologically improved.

• SWAT Land Cover Maps — South African National Land-Cover (SANLC) for 2013, 2018, and 2020.

• SWAT Soil Type Map — prepared from the Land Type Database of South Africa.

• SWAT-LUT — a standalone graphical interface for updating land use in SWAT models.

HAMSA (Under Development)

One of the key aims of the WRO is to provide a 'plug-and-play' hydrological modelling capability for South Africa through the HydrologicAl Model for South Africa (HAMSA) — an online platform based on HAWQS, a web-based water quantity and quality modelling system originally developed for the United States. HAMSA will enable users to simulate the effects of land management, climate change, and other scenarios on hydrology and water quality parameters — including sediment, nutrients, pathogens, dissolved oxygen, and water temperature — for any catchment in South Africa.

Hydrological Models

ACRU – Agrohydrological Model A multi-purpose, daily time-step hydrological model developed at the University of KwaZulu-Natal, widely used in South Africa for catchment water balance, streamflow estimation, and agricultural water use studies.

WRSM/Pitman Model The Pitman model is the most widely used monthly rainfall-runoff model in South Africa, forming the basis of the WR2012 national study and many water availability assessments.

MIKE-SHE (DHI) An advanced integrated hydrological modelling system for simulating the full land phase of the hydrological cycle, including surface flow, unsaturated zone, and groundwater interactions.

Soil & Land Data

ISRIC – Soil and Terrain Database for Southern Africa (SOTERSAF) A regional soil and terrain database for southern Africa providing soil physical and chemical properties for hydrological and agricultural modelling.

ARC – Land Type Maps and Memoirs Soil and land type classification data from the Agricultural Research Council, essential inputs for catchment modelling and land management planning.

Global Soil Moisture Data (ESA Climate Change Initiative) Long-term satellite-derived soil moisture datasets from the European Space Agency, useful for hydrological model validation and drought monitoring.

Remote Sensing & Earth Observation

Google Earth Engine A cloud-based platform for accessing and analysing satellite imagery including MODIS, Landsat, and Sentinel datasets — recommended as the primary access point for satellite data relevant to hydrological analysis. A beginner tutorial is available here.

Water Observation and Information System (WOIS) – Africa An ESA Tiger initiative providing earth observation-based water monitoring tools for Africa.

ESA Land Cover Maps and Tools Global land cover datasets from the European Space Agency Climate Change Initiative, useful as inputs for hydrological and catchment models.

Water Risk & Management Tools

Aqueduct (World Resources Institute) A suite of tools for identifying and evaluating water-related risks at local, national, and global scales, including water stress, flood risk, and drought exposure.

Water Administration System – Irrigation Schemes / WUAs Information on registered irrigation schemes and Water User Associations across South Africa.

WHAT – Web-based Hydrograph Analysis Tool An online tool for separating baseflow from streamflow hydrographs, useful for groundwater-surface water interaction studies.

Community & Support

Stack Exchange – Earth Science A community Q&A platform for hydrological modelling questions. Users are encouraged to create a profile and engage with the broader modelling community. More information is available here.