Kloof (including Forest Hills) was originally established in 1903 with its own administration but since 1996 has been part of the eThekwini Municipality.
It starts at the top of Fields Hill and is surrounded by Pinetown in the East, Westmead/Motala Farm on the South, Gillitts and Everton in the West and Waterfall, Molweni and Wyebank in the North.
The total area is approximately 25 square kilometers and a population of approximately 12 000 and is included in Ward 10 of the eThekwini Municipality.
Most of Kloof is situated on the Kloof plateau. This plateau comprises erosion-resistant Natal Group sandstone, which forms the orange-red, iron oxide stained cliffs found in Kloof Gorge which is part of Krantzkloof Nature Reserve.
River Sediments – The sediments which form the Natal Group sandstone were transported by river systems which flowed from an active mountain belt to the north, about 490 million years ago. At this time the earth lacked plant cover and the oceans were dominated by faunas such as trilobites (extinct arthropods), brachiopods (now mostly extinct clam-like creatures), echinoderms (ancestors of starfish and sea urchins) and corals.
Basement granites – Beneath the Natal Group sandstone are even older granite gneisses. These were formed in the roots of ancient mountains about a thousand million years ago at temperatures above 600 degrees centigrade, 10 to 20 kilometres beneath the earth’s surface. These mountain peaks, similar to those of the Alps or Himalayas of today, were gradually eroded until they were brought to the surface. Further erosion formed a flat surface onto which the Natal Group sandstone was deposited.
These granites are seen as huge dome-shaped boulders along the Molweni River bed and on hillsides above the river. They are coarse-grained crystalline rocks comprising the minerals, feldspar (which is milky pinkish-white), quartz (which looks glassy) and a few dark specs of a brown mica called biotite.
Dolerite intrusions – Between 300 and 180 million years ago a thick sequence of sediments (known as the Karoo Supergroup) was deposited on the Natal Group sandstone. This was followed by a massive upwelling of heat, known as a hot spot, from deep within the earth that melted rocks beneath the Gondwana supercontinent.
Molten rock (magma) forced its way through fissures in the earth’s crust and erupted as basalt lava flows on the surface. These fissures are known as dykes (if vertical) and sills (if horizontal).
Magma which crystallised more slowly in the dykes and sills is coarser grained than basalt and is known as dolerite. This is a blackish crystalline rock consisting of feldspar and pyroxene.
The numerous narrow and deep crevices that extend into the sides of the gorges cliffs, often a few metres wide and up to 50 metres deep are dolerite dykes which have weathered and eroded from the more resistant sandstone.
Rifting – This hot spot heralded the break up of the Gondwana supercontinent. The first Indian Ocean opened as a rift between Antarctica and KwaZulu-Natal. Extensive faulting and fracturing occurred. One of the faults is visible in the Natal Group sandstone cliffs on the southern side of the Molweni valley. The new drainage system into the rift zone produced the young Drakensberg escarpment, which over 150 million years retreated to its present position. At the same time erosion removed the basalt lava and Karoo Supergroup sediments. The Indian Ocean widened and Antarctica drifted to its present position.
Kloof is characterised on the largest part by hilly landscape cut by a myriad of drainage lines and streams as part of the Molweni River catchment which flows in a northerly direction through the Kloof Gorge eventually joining the Umgeni River in Lower Molweni.
The most notable feature of Kloof is Kloof Gorge with its stunning scenery which is the result of deep incisions of the Molweni and Nqutu Rivers into the Kloof plateau.
The southern section of Kloof drains into the Umbilo River Catchment.
The area is divided by the M13 freeway which runs East-West and by Kloof Falls and Bridle Roads which run approximately South-North.
Most of the Kloof area was grassland with riverine forests along streams and eastern scarp forest on the edges of Kloof Gorge. Most of the grasslands have been transformed by housing developments. Riverine forests are still common particularly in the steep and relatively inaccessible areas.
Kloof is situated at 500m above sea level and falls within the summer rainfall area of South Africa with an average annual rainfall of 1,075 mm. Rains can start from October and continue to March. Winter is generally dry with occasional rain.
Due to the altitude Kloof generally escapes the exceptional humidity which Durban is well known for.
Summer temperatures range from 18 to 32 degrees Celsius, with winter temperatures between 8 and 20 °C.