Surface Water

Rivers and Streams

The Limpopo River begins at the confluence of the Marico and Crocodile Rivers in the Limpopo Province of South Africa, it flows north to form the border with Botswana where it arcs east, and is joined by the Shashe River to form the border with Zimbabwe. From here it flows down the Great Escarpment and east into Mozambique at Pafuri, across the coastal plateau to the Indian Ocean at Xai Xai.

The Olifants River originates near Witbank, to the east of Johannesburg, running east, across the southern portion of the basin, to join the Limpopo River in Mozambique just after Massingir Dam.

The River basin has 24 distinct, main tributaries, which are listed in the table below; however, the Joint Limpopo River Basin Study Scoping Phase report proposes a further subdivision to create 27 more equally sized and geographically homogenous sub-basins.

The contributions to the overall flow of the Limpopo River are somewhat determined by rainfall. Estimates of mean annual rainfall per sub-basin are presented in the Climatic Patterns section of the Climate of the Limpopo River basin. However, the majority of the surface water flow originates in the Drakensberg Mountains and South African highveld (Leira et al. 2002), feeding the Crocodile, Marico and Olifants Rivers.

Limpopo River tributaries ranked by estimated present-day Mean Annual Run-off.

Country	Tributary	Catchment Area (km²)	Naturalised Runoff (million m³)	Denaturalised Runoff (million m³)	Unit Runoff (denat. MAR) (mm)
South Africa	Marico	13 208	172	50	3.8
South Africa	Crocodile	29 572	391	205	6.9
Botswana	Notwane	1 853	55	24	1.4
South Africa	Matlabas	3 448	382	21	6
South Africa	Mokolo	7 616		117	15.4
Botswana	Bonwapitse	9 904	15	15	1.5
Botswana	Mahalapswe	3 385	13	13	3.9
South Africa	Lephalala	4 868	150	99	20.3
Botswana	Lotsane	9 748	62	62	6.4
South Africa	Mogalakwena	20 248	269	79	3.9
Botswana*	Motloutse	1 953	111	111	5.8
Total for upper reach		139 103	1 620	796	5.7
Botswana	Shashe	12 070	250	250	20.7
Botswana	Other	7 905
Zimbabwe**	Shashe	18 991	462	462	24.3
Zimbabwe**	Umzingwane	15 695	350	350	22.3
South Africa	Sand	15 630	72	38	2.4
South Africa	Nzhelele	3 436	113	89	26
Zimbabwe**	Bubi	8 140	53	53	6.5
Total for middle reach		81 867	1 300	1242	15.2
South Africa	Luvuvhu	4 826	520	492	102
Zimbabwe**	Mwenezi	14 759	256	256	17.4
Zimbabwe**	Other	4 956	36	36	7.3
South Africa	Elephants	68 450	1 644	1233	18
South Africa	Other	13 996	2 352
Mozambique	Changane	43 000
Mozambique	Elephants	1 550
Mozambique	Other (e.g. Lumane)	40 431	315
Total for lower reach		151 537	5 123	2017	21.7
Total		412 938	8 043	4055	9.8

* Denaturalised MAR will change when utilization of the Letsibogo Dam increases.
** According to Görgens and Boroto (1999), the MAR for Zimbabwe is the denaturalised MAR; according to GOZ–MRRWD–DWD (1984), the given MAR is the naturalized MAR. Sources: Görgens and Boroto (1999); GOSA–DWAF (1991); GOSA–DWAF (2003 a–d); GOB–MMRWA (1992); GOZ–MRRWD–DWD (1984); FAO (1997)

Source: FAO 2004

Estimated run-off per sub-basin is displayed in the map below (left).

Pans and Vleis

A pan is a depression in which water collects when the soil layer is saturated, usually following heavy rainfall. Pans form where the water table is close to the surface, with water usually dissipating through evaporation, rather than outflow to a stream or river, but this is not excluded.

Vleis - types of marshes or wetlands - are usually more permanent features in areas where the water table is consistently or more frequently close to the surface. The distribution of wetlands in the Limpopo River basin is discussed in more detail in the Wetland section of the Ecology and Biodiversity Chapter.

Surface Water Monitoring

Each country of the Limpopo River basin has its own surface water monitoring infrastructure and procedures, which vary to some degree in extent, time frame, but follow similar methods (LBPTC 2010). However, a SADC-wide monitoring programme of automated flow-gauging stations, known as SADC HYCOS (Hydrological Cycle Observation System) has been put in place to facilitate regional hydrological information gathering and sharing.

National surface water monitoring and SADC HYCOS are discussed in more detail in the Existing Monitoring section of the Resource Monitoring Chapter of Resource Management.