Luvuvhu Catment = 5 941 km²
Mean annual precipitation (MAP) = 608 mm
Mean annual evaporation = 1 678 mm
Mean annual runoff (MAR) = 519 million cubic metres (range from 85 to 1 900 million cubic metres)

The Luvuvhu Catchment forms part of the larger Limpopo system, which extends into Mozambique. The Luvuvhu River and some of its tributaries (including the Mutshindudi and Mutale rivers) rise in the Soutpansberg Mountains. The Luvuvhu River flows for about 200 km through a diverse range of landscapes before it joins the Limpopo River near Pafuri in the Kruger National Park.

Dams in the Luvuvhu River catchment include the Albasini Dam and the smaller Mambedi, Tshakhuma, Damani, Vondo, and Phiphidi Dams, of which the latter two lie in the Mutshindudi River. The Nandoni Dam is currently being constructed in the middle section of the Luvuvhu River east of the confluence with the Dzindi tributary and east of the town Thohoyandou.

The upper Luvuvhu, Sterkstroom, Latonyanda, Dzindi, Mukhase, Mbwedi and Mutshindudi are steep, narrow rivers dominated by cobble riffles and occasional pools with a few bedrock rapids. Large waterfalls in the upper Dzindi and Mutshindudi rivers create natural reach breaks and barriers to fish migration.

The lowveld reaches of the Luvuvhu and Mutshindudi rivers have diverse habitats where rapids, riffles, runs and pools occur. The river channel is incised into the landscape.

The Tshirovha and Tshiombedi tributaries to the Mutale River are steep with both bedrock and fixed boulder rapids. Habitats in the Mutale River are exceptionally diverse. Only two small weirs occur in the Mutale River.

Near the western Kruger National Park border, in the steep Lanner Gorge, the Mutale River joins the Luvuvhu River.

The Luvuvhu River and all its tributaries rising in the Soutpansberg are perennial.

Luvuvhu Headwaters

Land-use activities include forestry (11%) and agriculture (20%). Forestry plantations cover 44% of the upper reaches of the Luvuvhu and Latonyanda rivers, decreasing to less than 10% towards the Albasini Dam and confluence in ecoregion 5.04. Subsistence farming is about a third of the total agricultural component.

Luvuvhu River

The riparian vegetation consists of dry acacia woodland species. Riparian vegetation in large areas has been removed to accommodate orchards. Alien vegetation such as eucalypts, poplars and Mauritius thorn invade the riparian zone.

Several introduced fish species such as black bass and common carp occur in the Albasini Dam.

Sterkstroom River

Smallholdings that are developed intensively for orchards occur along the river. A very narrow riparian strip is left because of orchards planted to the waters edge. Herbicide and insecticide spraying and fertiliser application have negative impacts on the water quality.

The Effects of Changes in Land-use on Floods

Forestry, poor agricultural practices, deforestation and urbanisation affect the rainwater run-off from the land. Man-induced changes to catchments increase the intensity and shorten the duration of floods. In areas where land-use practices are poor and where riparian vegetation is being removed, flood events accelerate bank and donga erosion.

Latonyanda River

Luvuvhu River

Alien species that are abundant include lantana, bugweed, guava, castor-oil plant, syringa and eucalypts.

The upper Dzindi River flows through a forestry area before it plunges down a large waterfall. Plantations cover about 35% and subsistence farming 26% of the upper Dzindi Catchment (ecoregion 2.01). The main land-use of the lower Dzindi River is subsistence farming, covering 45% of ecoregion 5.04.

The marginal riparian vegetation of this Luvuvhu reach is dominated by reeds. Pre-flood conditions included large beds and reed islands. The dominant land-use is subsistence farming.

Upper Dzindi River

The local community farm on the steep slopes adjacent to the upper reaches of the Dzindi River. Some grazing occurs as well as cutting of trees in the riparian zone.

Natural Barriers Influence the Occurrence of Fish Species

Where natural barriers like waterfalls occur, the fish community above the barrier is often different to that below. While some species may never have occurred above the barrier, drought, fires, cold spells, toxic spills, alien predators and overfishing may eliminate species in the upstream reach. When species are lost through events like these, it is necessary to consider restocking programmes. Below the waterfall in the upper Dzindi River, the barred minnow (red data species) is found as well as the scarce line spotted barb. There are no records of these two species above the waterfall.

Dzindi River

Luvuvhu River

Alien vegetation such as lantana and castor- oil plants are common along the Luvuvhu River.

The riparian vegetation in the area of Thohoyandou has been largely destroyed for use as firewood and to provide grazing. This has led to increased donga erosion. Large, dense stands of trees occur at intervals.

Luvuvhu River

Community activities include fishing, bathing and washing of cars. Clay is removed from the riverbank for use in brick manufacturing. These pressures damage the channel banks and impact on the water quality.

Upper Reaches of Mutshindudi and Mbwedi Rivers

Upper Mutshindudi River

Rural Practices along the Mutshindudi River

The underdeveloped rural regions of the Northern Province are subject to severe environmental degradation. Rural communities with a low per capita income are highly dependent on available natural resources, including riparian and aquatic resources, for survival. Limited environmental awareness and a lack of infrastructure and planning for sustainable utilisation worsen the situation.

Due to poor reticulation infrastructure, many people use water directly from streams for household purposes. The washing of laundry in rivers is a common activity. There are no other water sources available. No refuse removal system or functional recycling process exists.

Fish is an important protein source and a large proportion of the rural community eat freshwater fish. Methods of fishing include line and hook, gill nets, seine nets and traps. At this time, fishing effort is starting to show signs of overexploitation.

Rural Agricultural Practices

Agriculture (small scale subsistence and commercial crop production) is the main economic activity in the Mutshindudi River catchment. Traditional cattle farming, irrigated estates and schemes, rain-fed orchards and irrigated informal gardens are expanding. The land tenure system has resulted in the overstocking of cattle and goats with resultant high levels of erosion.

The riparian vegetation is over-utilised, mainly for firewood, fence construction, furniture, medicinal purposes and food. In many areas, the riparian vegetation has been completely replaced by crops and as a result, siltation of the river is increasing.

The resultant health of the riparian zone along the Mutshindudi River is deteriorating. Sediment inflows into the Mutshindudi are likely to increase, causing loss of in-stream habitats and eventual loss of fish and invertebrate species from the river.

Waterfalls occur in the steep upper reaches of the Mutshindudi River.

Middle Mutshindudi River

The Importance of the Riparian Zone and Why It should be Conserved

Riparian vegetation plays a very important role in protecting river ecosystems by:

Riparian vegetation is vulnerable to invasion by alien plants.

Indigenous vegetation stabilises river banks.

Mbwedi River

The Damani Dam supplies water to the coffee estates. There is no mechanism for releasing water for the environment from the dam. Weirs and pump stations contribute to the unnatural flow in this section of the river.

The Mutale River

Subsistence farming is the dominant form of agriculture in the Mutale Catchment. Almost all the agricultural activities in ecoregion 2.01 and ecoregion 5.04 are associated with subsistence farming.

Local communities use the river for washing clothes and cars, causing erosion, sediment and solid waste.

Mutale River

A road bridge and overgrazing cause erosion with resultant sedimentation in the river.

Aquatic Biota Benefit from Floods

Floods provide natural cues for fish and invertebrates to breed. Flooded marginal habitats provide sheltered areas for some fish to breed and for juvenile fish to develop.

Lower down in the catchment, floodwaters are responsible for maintaining the connectivity of estuaries to the open sea. Estuaries act as important breeding grounds for many marine species. Open estuaries permit the migration of species such as eels to the upper catchments, where they play an important role in the river’s ecology.

Mutale River

Lower Mutale River

The Tshiombedi and Sambandou Rivers - Tributaries of the Mutale River

The Tshiombedi River has a steep gradient with waterfalls. Above the waterfalls, the river is almost natural with none or very little human impact.

The Sambandou wetland is a source area for both the Luvuvhu and Mutale rivers.

Tshiombedi River

Sambandou River

Wetlands attenuate floodwaters

Wetland habitats act as sponges that help to attenuate floodwaters.

On a global basis, wetland habitats are amongst the most threatened habitat types. Wetlands are being drained to provide agricultural lands, to provide space for urban development and to reduce risks of diseases such as malaria, or are being dammed.

Destruction of wetland habitats is one of the man-induced changes that influence the intensity and duration of floods.

Floodwaters Recharge Aquifers

Floodwaters are important for the recharge of aquifers and for the general flushing and cleansing of the river system. Flooding is often followed by several seasons of strong low flows, which allow aquatic communities to recovery.

While very high flood flows are natural, it can be argued that the amplitude and frequency of flooding has changed due to human impacts. Under very high flows, river channels may change drastically and long established indigenous vegetation may be destroyed.

The 2000 floods made significant impacts to the lower catchments of the Letaba and Luvuvhu Rivers. Scientists have little information with which to indicate whether these changes are completely natural, or are attributable to the combined effects of nature and poor catchment management practices.

The Luvuvhu River in the Kruger National Park

Migration Barriers and alien fish species

Recently, a number of highly invasive alien fish have been recorded in the Limpopo River. As a result, there is now a debate over the benefits of erecting fishways on proposed new dams, since the structures may permit free passage of these invasive species across barriers and deeper into the river systems. Each dam should be assessed individually.

Luvuvhu River

Land Disturbance and Alien Plants

South Africa has many problem invasive alien plant species that out-compete and displace indigenous vegetation.

Alien plants are often associated with disturbed areas caused by floodwaters and are the first to recolonise bare ground. These alien plants do not perform the same function as indigenous riparian vegetation and in areas where they are prolific, river banks can become very unstable. The cycle of disturbance and infestation is very difficult to break.

Luvuvhu River

The Rivers and the Riparian Vegetation are Home to many Bird and Animal Species.

The extensive riverine forest on the banks of the Luvuvhu River is a very important habitat. A large variety of organisms are dependent on the riparian zone in this dry landscape, including riparian birds and rare bat species.

The riparian trees are also home to special bird species such as fish owl, tropical bou bou, longtailed starling and white backed herons.

The hippos in this area almost became locally extinct during the 1992/3 droughts. The original 100 individuals declined until only one was left. Since then the hippo population has recovered to about 20 with individuals coming in from the Limpopo River and the flood plains.

The high biodiversity in this area can be attributed to the geographic location as well as the diversity of landscape features. Three biomes converge in the Pafuri area.

Nine geological features with contrasting rock types are found, including quartzite, sandstone, mudstone, shale and basic lavas.

Extensive areas of floodplain alluvium occur at the confluence of the Luvuvhu and Limpopo rivers. Several landscape features are found in this wetland, which include riverine forest, riparian floodplain forest, floodplain grassland and river channels and pans.

The riverine forest is confined to the riverbanks. It consists of large, broad canopied trees more than 20 m in height.