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Category: 2016 - January
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Also known as “Bass Lake”, it offers sheer perfection on a hot, windless day.

My profession as marine and coastal ecologist has taken me to many coastal environ- ments throughout the world. On the basis of this experience I can say with conviction that Betty’s Bay, with its mountains, forested gorges, fynbos-dominated coastal plains, rivers, lakes and wetlands, dunes, beaches and the sea, ranks amongst the best.

A quite remarkable fresh water body in Betty’s Bay has the unusual name of Malkopsvlei. The story goes that the area around this lake was used in years gone by for cattle grazing. Obviously the cattle came to the lake to drink. However, when they ventured in too far, they got stuck in the slushy mud of the bottom and in their panic went ‘malkop’. To avoid this from happening, the owner of the cattle is said to have filled in the shallow, eastern part of the lake with dune sand. Hence the sandy bottom of the eastern periphery which is such a boon to those who play and swim in the lake today. I cannot vouch for the correctness of this story, but what is interesting is that there is a huge hollow in the dunes immediately on the seaward side of the ‘filled in’ area. So it seems as though there may well be truth in the story. Many years later, large-mouth bass were introduced into the lake and it is therefore often referred to as ‘Bass Lake’.

The configuration of the lake is equally interesting. It is about 350m long (measured by GPS & Google), 80m wide in its outlet region and it has a maximum depth of about 2m. Water reaches the lake from various sources. A major part of the wetland area westwards of Dawidskraal between Bass and Reed Roads drains into Malkopsvlei and it receives water from the Betty’s Bay Mountains via streams and sub-surface flows. It also receives water from the kloof and waterfall above the Betty’s Bay Shopping Centre and Garage. As the run-off water from the mountains is rich in tannins, it is typically dark. In scientific jargon Malkopsvlei is therefore referred to as a black-water system.

In spite of hot and uncomfortable conditions and attacks by thousands of midges and ants, the traversing of the channel was a memorable experience. This is, in fact, a remarkable piece of wilderness in the Betty’s Bay environment. Amongst others, I came across otters, snakes and an exceptional variety of bird-life.

The outlet of Malkopsvlei to the sea is particularly interesting. Instead of opening directly into the marine environment via the shortest route over a distance of some 300m through the dunes and across the beach, lake water flows through a deep trough between two old and stable backshore dune systems to enter the sea at a sandy beach inlet, some 1.5km to the east, near Dawidskraal. The channel banks and upper edges consist of very steep sandy slopes consolidated by typical dune vegetation dominated by Olea-, Maytenus-, Colpoon-, Metalasia- and Passerina scrub. In the lower, damper sections of the outlet channel, this scrub merges into swamp vegetation, dominated by various species of reeds, especially Phragmites. Milkwood trees are common along the damper parts of the channel.

Towards the end of 2002, there was a suggestion that widening of this outflow channel might enhance drainage from Malkopsvlei and hence reduce high bacterial loads which had been measured during the summer months. I was worried about such artificial interference with a natural and stable aquatic system. That prompted me in December 2002, to work my way from the sea near Dawidskraal to Malkopsvlei along the entire length of the channel, wearing wetsuit, pants, booties and armed with a camera capable of taking photos above and below water.

The investigation led me to recommend that artificial widening of the channel should be avoided at all cost, as disturbance of the steep vegetation-bound channel slopes would inevitably lead to dune subsidence and hence the likelihood of total blocking off of the exit channel - with serious consequences for the entire lake system.

In spite of hot and uncomfortable conditions and attacks by thousands of midges and ants, the traversing of the channel was a memorable experience. This is, in fact, a remarkable piece of wilderness in the Betty’s Bay environment. Amongst others, I came across otters, snakes and an exceptional variety of bird-life.

Sadly, Malkopsvlei continues to be subjected to severe and increasing human impacts. All-important peripheral sponge and wetland areas, which formerly acted as filters and which replenished the lake through the slow release of water during the dry summer months, have been drastically degraded by houses, roads and other infrastructure. Pollution by leaking sewage conservancy tanks is a serious problem. Surface water run-off has been concentrated by road culverts which, in turn, affect ground water levels. Pollution is furthermore exacerbated by stormwater run-off. In addition, many Betty’s Bay dog owners enjoy using the lake as playground for their dogs. While the romping dogs are a pleasure to watch, they foul the immediate periphery of the lake, including the grassed verges where people sun-bathe and children play.

The overall consequences of these various sources of pollution are two-fold:

Firstly - the risk of unacceptably high bacterial levels, especially of Escherichia coli and at times of filamentous algae, both of which are hazardous to human health.

Secondly - encroachment into open surface areas by the reed Phragmites australis as a result of high nutrient levels in the water reaching the lake.

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Water quality is tested weekly and, if necessary, the lake is closed to swimmers until the pollution levels drop.

These undesirable ecological and human health indicators unfortunately make their ap- pearance during the hot summer months when the occupancy of houses and recreational use of Malkopsvlei are at their highest. In the past, this has forced Overstrand Municipality to prohibit swimming in the lake during the summer holiday period. It would be a huge loss to the allure Betty’s Bay if the recreational and scenic benefits of Malkopsvlei enjoyed by generations of residents and visitors, were to be jeopardized.

Can this danger be averted? Probably yes, but only if strong collaborative steps are taken, including:

The Water and Sewage Committee of the Betty’s Bay Residents and Ratepayers Association are collaorating with the Municipality. But it is clearly of vital importance that all residents do their bit by adhering to preventative measures such as those outlined above.

[ 11 December 2015]