The waters of Table Mountain – Part 3: Streams & Ravines

Jun 12, 2012

It is one of the many joys of hiking Table Mountain to come upon a burbling stream, a secluded pool or a cascade pattering down on solid rock from up high. The atmosphere that these features create acts as an effective medium through which we connect with nature. Few sounds instil as much serenity as the trickle of water on a mountainside or the clicking of frogs beside a backwater pool. Add to that the geological drama and floral extravaganza on display on Table Mountain, and you understand something of the mountain’s appeal.

But Table Mountain’s waterways are in a constant state of fluctuation. Parched streambeds in summer transform into gushing torrents in winter. Few perennial streams occur on the mountain. Some of the ravines that carry water throughout the year include Platteklip Gorge (lower reaches only), Disa Gorge, Window Gorge and Skeleton Gorge. Even these often end up half-dry by late summer (February / March), their water reduced to an underground seep, only to burst into life again in June at the onset of winter. Some hiking routes leading up ravines become treacherous and nigh on impassable during the winter months, when sections are transformed into foaming streams.  Skeleton Gorge is such a route; graded A (technically the easiest grade), it feels more like a C-grade after a winter storm.

Mountains are known to be the birthplace of rivers, and Table Mountain with its flat summit catches a lot of rain that drains down the many ravines dissecting the mountain. The mountain’s proximity to the sea barely allows its streams to grow into fully-fledged rivers. During the winter months, a single deluge can transform a placid stream into a raging torrent. Runoff is fast and furious due to the steep terrain, and there is little water retention; less so in summer, when the mountain is parched and acts as a sponge. Hiking Table Mountain in winter, one has the privilege of tracing streams right to their source, where they start their journey to the sea as seeps near the summit. Hundreds of seeps merge to form a stream, in turn joining other streams as they get funnelled into ravines, swelling into torrents that thunders down the mountain.

I often get asked about waterfalls on Table Mountain. These only really come into being during winter, when Table Mountain receives 70% of its annual rainfall. Well-known and conspicuous waterfalls include Hell’s Gates in Disa Gorge, the cataract in Skeleton Gorge at its junction with the Contour Path, Blinkwater waterfall, Grassy waterfall and Fountain waterfall, taking the names of the ravines they occur. Grassy waterfall must rank as one of the longest and strongest on the mountain, as it can easily be seen from 700 meters down, appearing as a white ribbon on the eastern slopes of the mountain. Located high up the mountain in an inaccessible area, no one bothers to make the trek to its base.

A detail often remarked on about Table Mountain’s water is its amber color. Streams in the Western Cape are often referred to as blackwater streams, as the amber color takes on a black appearance in deep pools. The color is caused by chemical compounds, called polyphenols – specifically tannins, leaching out from dead leaves. Plants on Table Mountain produce polyphenols as a defence against herbivores, as it makes the leaves unpalatable. The presence of polyphenols only affects the water’s color, not the taste. And it’s perfectly safe to drink. Some streams on Table Mountain filters through clay soils, allowing the polyphenols to bond chemically with the surfaces of the clay granules, ridding the water of its amber hue. A good example is the Platteklip Stream, whose water emerges crystal-clear at a point just above the Contour Path in Platteklip Gorge.

Which brings us to the existence of subterranean streams on Table Mountain. I know of three places on the mountain where water mysteriously emerges or disappears; and no doubt more such places exist. One is the Platteklip Stream, mentioned above, lifeblood of Cape Town up until the 1880s. Clearly visible along the gorge’s lower reaches, the stream disappears a short distance above the Contour Path, never to be seen again. Even in high winter, with water flowing down all the ravines on the mountain, the middle and upper reaches of Platteklip Gorge remain waterless. In the Valley of Isolation on the Twelve Apostles, a small cave allows one to see water flowing through the mountain – east to west – its outflow still a mystery.

Another unique aspect of Table Mountain’s water is its presence on the upper plateau (the actual tabletop). For much of the year, large parts of the summit plateau are waterlogged. The eastern table is known for its boggy terrain, and even features a lakelet, or small natural pool. About a meter deep during winter, it gets topped up by the moisture-laden Tablecloth cloud-formation during the long, dry summer months, when it dwindles to barely more than a marsh pit. As for swimming possibilities, it’s too cold to enjoy in winter and too shallow in summer, but fun and invigorating to wallow in on sultry spring days, when the water level is fairly high.

Last but not least are the springs of Table Mountain – those rare places where a seep or drip can be found even in summer, when the mountain bakes under a torrid sun and the heat shimmers off dust-dry watercourses. Several springs exist on Table Mountain – and no one can profess to know the whereabouts of them all. Back in the early days of mountaineering, hikers and climbers relied on springs for their water supply. In the 1940s and 1950s, some were graced with small ponds to pool the water for convenient drinking. Nowadays, hikers and climbers carry their own water, only resorting to springs when their own supply run dry.

The history of Cape Town and its people is entwined in the streams that flow off Table Mountain. The city has the mountain to thank for its existence. As hikers and climbers, we continue to draw sustenance from Table Mountain’s streams, sometimes to quench a thirst or revive the body, but more often to drink in the vitality and peace it brings to the surroundings.

Only by hiking Table Mountain can you expect to experience the mountain’s water features. They’re more impressive in winter, but more appreciated in summer.