Geographical features

Location

The Seven Dams Conservancy and the associated areas lies to the north of Bloemfontein and is situated between the N1 National Highway in the west, including the Bloemfontein Botanical Garden, the farm formerly known as Lilyvale 2131, the hills to the north included on the farm ‘The Kloof’ 2921 and Bayswater 2868 adjacent to Eeufees road which passes North Ridge Mall.

Geology & Soils

The geology of the Seven Dams area is relatively simple. It is composed of dolerite dykes and exposures of sheet rock sills, which cap the underlying sedimentary rocks of the Adelaide Subgroup (Beaufort Group, Karoo Supergroup). These dolerite intrusions, both dykes and sills were laid down in their molten state during Jurassic times, some 65 million years ago. The soils are generally shallow (1 – 5 cm on the rock sheets, average of 30 cm, and exceptionally deep 90 – 120 cm in the riverbed at the Bloemfontein Botanical Garden (Müller 1970, Mucina & Rutherford 2006). A layer of red sand of aeolian origin overlays the dolerite sheet rock with shallow, dry gravelly soils on the grassy plains, while deeper clayed soils occur in the bottomlands of streams and wetlands.

Climate & Moisture Availability

Bloemfontein has a hot, wet summer and dry, cold winter. Precipitation is between 457-mm (Gh 5 Bloemfontein Dry Grassland) to 566-mm (Gh 8 Bloemfontein Karroid Shrubland), with mean monthly temperature varying from a minimum of – 2°C to a maximum of 30°C.

Climate change and the predicted reduction in precipitation and increased global temperature will all have a profound impact on the Free State, Bloemfontein and the Seven Dams area in particular. This is all problematic for the Mangaung Municipality and the planned housing developments, which will impose ever-increasing demands on the fresh drinking water supply.

Habitats and plant communities

The plants found in the Seven Dams Conservancy and the adjacent areas occur in four broad habitats. These habitats are:

1. Succulents and dwarf shrubs growing on sheet rock and stony outcrops
2. Mesic and Highveld Grasslands
3. Azonal Wetlands
4. Woody Shrubland on the hills to the north

Bloemfontein Karroid Shrubland

The sheet rock and stony outcrop community have now been given the vegetation classification of Gh 8 Bloemfontein Karroid Shrubland, (Mucina & Rutherford 2006).

The 1937 report of Potts and Tidmarsh, entitled ‘An ecological study of a piece of Karroo-like vegetation near Bloemfontein’, recognised that the Seven Dams, Bayswater, Lilyvale and the present Botanical Garden areas had a unique succulent plant assemblage with species related to Karroo vegetation. The occurrence of the Karroid-type vegetation ‘well within the greater grassveld region aroused interest: it demonstrates the development of a similar type of vegetation as a result of similar conditions, and relates to the question of origin.’

Grassland Biome

The majority of the Free State, including Bloemfontein and the Seven Dams area, falls within the Grassland Biome of South Africa. South Africa has eight Biomes with the Grassland being the largest, and arguably, the most important. Within the Grassland a number of sub-units occur which have been mapped and given specific designations (Mucina & Rutherford 2006).

The Seven Dams and adjacent areas described in the Environmental Management Plan have elements of three grassland sub-units. The first two are defined by the annual rainfall of less than 500mm, which is the major environmental factor controlling vegetation patterns, and falls within the ‘sweet’ grasses, which comprise the Dry Highveld Grassland.

Azonal Wetlands

Wetlands do not constitute a biome but are found within all eight Biomes in South Africa. The wetlands found at the Seven Dams area can be divided into two categories:

1. Open bodies of water formed by manmade dams filled by seasonal rain
2. The seasonal streams and associated wetlands reliant on annual rain

A precise definition for the wetlands is problematic. The topography is steep with mostly dolerite bedrock and sheet rock and limited development of soil horizons. The seasonal streams are narrow and confined to rocky areas. The streams are intermittent and completely dependant on rain, thus flow is only after rain, and then for a limited time.

Woody Shrubland

There is a ridge of koppies to the north of the Seven Dams Conservancy, stretching in a north-westerly direction to the Bloemfontein Botanical Garden. The vegetation on the south side of these hills is recognised as being distinct and has been described as Gh 7 Winburg Grassy Shrubland (Mucina & Rutherford 2006).

These koppies have afro-montane elements of vegetation found in the Drakensberg some 400-km to the east. The hills to the south and south west of Bloemfontein do not have these vegetation types and this underlines the ecological uniqueness of the area as well as the need to conserve this rapidly diminishing landscape and vegetation component.

Plants

Pachypodium succulentum

Chasmatophyllum musclinum

Euphorbia mauritanica

Strumaria tinela

Orbeopsis lutea

Dicoma macrocephala

Stomatium mustelliumv

Ruschia harmata

Ruschi unidens

Psammatropha

Massonia jasmiminflora

Ruschia hamata

Orbea cooperi

Kniphofia sp with Ruschia spinosa

Aloe grandidentata

Boophane distichum

Heliophylla carnosa

Lobelia laxa

Crassula nudicaulis

Albuca setosa

Stapelia grandifllora in bloom

Stapelia grandifllora

Ledebouria ovatifolia

Anacampeseros filimentosa

Birds

Watch this space for interesting information on the birds of the 7 Dams Conservancy.

Animals

Seven Dams and the broader area is a mix of habitats, grassland, wetlands and woody shrublands with shallow soils, flat open expanses of bedrock, sheet rock and steep hill slopes. This variety of terrain provides numerous niches for animals, from insects to small antelope species. There are several endemic animal species, which add to the rich biodiversity of the unique terrain found in this area of Bloemfontein.

A total of 367 animal species is recorded for the area, with 2 endemics found within the grassland (one Spider, one Scorpion). One species is facing the imminent threat of extinction and 4 species have insufficient data to determine if they are Endangered, Vulnerable or Threatened. An endemic animal or plant species is one that is found only in that area, generally a small geographic region. In some cases it may only be several square meters.

Conservation issues

As stated in the Mangaung Local Municipality – Urban Open Spaces Framework, point 3.1.1.2 page 12:

  • The natural flow of water over any public open space may not be obstructed by any means (e.g. groundworks, surface pollution, illegal occupation etc.);
  • The natural migrations of wild fauna and flora within an urban open space system will be encouraged and may not be obstructed through land redevelopment without sufficient mitigation actions.

The current housing developments to the south and east and the proposed or planned developments to the west of Seven Dams Conservancy ignore both these points in the Policy. There is no reason to assume that proposed developments to the east on Bayswater 2868 and Lilyvale 2313 will be any different. Additionally, due to the topography, the major water system that feeds all the seven dams, is drained to the east on Bayswater 2868. Any construction on this land to the top of the catchment contour line (Figure 2.1) will immediately and permanently affect Seven Dams Conservancy, the landowners and SANBI Bloemfontein Botanical Garden. The sewer line which runs in and very close to the stream in Bayswater 2865 regularly overflows after heavy rain, spilling raw sewage into the stream which then pollutes the dams and other water ways down stream (e.g. personal observation in February 2008, phone call from Dr. Gouws complaining of pollution 2008). This is in contradiction to the engineers’ reports on the capacity of the sewer line to handle the volume of liquid. This report is attached to the Scoping report for the proposed development of Bayswater 2865. This system is unable to cope with the present strain put on it without any further development as proposed by the plans for the area. Photos documenting this and e-mails to the Municipality are attached in Appendix 18.

Site visits to current and adjacent housing developments all show the complete and absolute eradication of all existing indigenous plants and their community associations. This housing development also destroys the bedrock by extensive excavation and use of explosives. Bulldozers remove the topsoil to bedrock and expose extensive totally barren areas. These are immediate sources of wind erosion with additional loss of soil by washing away by rain and runoff water from adjacent house gardens and sewerage systems. Alien invasive weeds rapidly colonise the exposed areas and establish extensive settlements. Once construction of the houses is completed, the resulting vegetation planted is almost exclusively exotic and, requires watering and irrigation systems, which strain existing scarce drinking water. The housing developers usually replace indigenous plants with cultivated exotics. Lawns are often established using the pervasive and invasive exotic Kikuyu grass (Pennisetum clandestinum) which also requires constant watering and mowing.

Recommendations given in Environmental Impact Reports of surrounding areas are never adhered to (e.g. Somerton at present). This is also the result of the total lack of supervision of heavy machine operators as well as the need for suitable training and education of workers, housing developers, architects and urban town planners. The current mentality is one of expediency where it is easier to completely destroy all plants and the associated habitats and replace them with an alien and completely new environment.

It would show sound ecological ethics and environmental conservation morals to have as part of housing developments a mandatory indigenous re-plant scheme. This should be viewed as part of the built-in environmental cost of development.

A suitable environmental landscape gardening management plan could be established to provide guidelines as how to replant, both in gardens and along streets. There are numerous nurseries in Bloemfontein as well as the Botanical Garden, which cultivate indigenous plants. Mandated replanting with indigenous plants would have the added economic benefit to the nurseries of increasing sales and generating more revenue. There would also be an educational component for the citizens of Bloemfontein who would become aware of the richness of their indigenous and unique plants.

Archaeological sites

Numerous stone tool sites exist in the greater Seven Dams area. These range in age from Middle to Late Stone Age, and show the occupation, use and habitation by our ancestors over a period of human history ranging from 500 to 250 000 years and the present day.

Additionally, the whole area is rich in artefacts and constructions from the Anglo Boer war. There are also two sites containing graves. One site in Lilyvale has close to 195 graves (abridged report Appendix 3) and the other site marked on the municipal map contains several graves and is in the Seven Dams Conservancy.

Stone age tools

Stone age tool with scale