Kate Hodge and Fred and Karen Ellery, collaborated on putting together a fascinating weekend for the Oldenburgia Hiking Club, recently.
Kate Hodge and Fred and Karen Ellery, collaborated on putting together a fascinating weekend for the Oldenburgia Hiking Club, recently.
The base was Cape St Francis where the group of 18 club members and a support team of 3 gathered in anticipation of what was destined to be a fascinating weekend.
At the heart of it is understanding the impact of geomorphological and other environmental processes and their importance on residential planning. A lack of understanding of the processes at play has proved to be catastrophic for some. As much as we like to believe that we can control nature, it will often come back to bite us!
On the Saturday the group was transported to Oyster Bay to the west of Cape St Francis. The drive passed through the alternative energy field of some 40 wind-turbines, part of the Oyster Bay Wind Farm.
The majesty of the structures is quite striking as one gets up close, and the measured rate at which they turn was quite ominous, as they faced into the gentle westerly wind. It was at the Oyster Bay Car Park, just below Oyster Bay Beach Lodge, that the hike leaders said to the group, “To the light-house!”, and off we went.
The 18km coastline hike – which was to take us to the light house at Cape St Francis – took us a good eight and a half hours. Yes, there was the proverbial “tea break”, as well as a well-deserved lunch stop at Scholtzkraal at the 12km mark, and of course a number in the party took every opportunity to have a refreshing dip in the turquoise sea.
Walking through coastal fynbos in the cool of the morning is always refreshing, and we were all struck by the enormous natural beauty of this coastline. The 2km strength of beach at Thysbaai, just before the Rebelsrus Private Nature Reserve – and the site of the first swim – was pristine, similar in feel to those long stretches of beach on the Transkei coast.
However, many commented on how disappointing it was to see how much plastic debris was caught in many of the rocky outcrops, clearly deposited surreptitiously by members of the international shipping fraternity. Large crates, thick rope, polystyrene blocks the size of coffee tables, and water bottles of unusual shapes littered the rocky shoreline. One wonders how it's possible to put a stop to this as one surveys those two contrasting realities.
A key feature of the day walk was the charred landscape as a result of a recent and seemingly devastating fire through the coastal fynbos vegetation, which required huge efforts by landowners to save homes along the coastline from destruction, and which led to the loss of a limited number of homes. Nevertheless, fire is an integral part of fynbos landscapes such that without it, there is a substantive loss of biodiversity associated with local extinctions.
The intensity of the fire was aggravated through the presence of alien species, especially Acacia cyclops, such that the intensity of the fire and its impact on coastal ecosystems was particularly severe. Fire is an integral part of the fynbos environment that is impossible to prevent given the right amount of biomass and suitable weather conditions. In this regard the marriage of fire as an essential and inevitable ecological process, and coastal development, poses great challenges.
The club committee was very fortunate to have secured the necessary permission to walk the whole stretch between Oyster Bay and Cape St Francis, thanks to Hennie de Beer of Eskom and land owners from Rebelsrus Private Nature Reserve and Mostertshoek. That evening as we tucked into two delicious chicken potjies which had been put together by Mike Godlonton – with some expert input from a number of the members of the club – we all felt an enormous sense of privilege to have been given this opportunity.
The following day saw the group rise a little later. Our first stop was the St Francis Bay beach, where Fred Ellery talked us through the flow of ecological processes that had contributed to the disappearance of the beach over the last 3 decades. In the past, the natural supply of sand to the beach was from Oyster Bay, carried on prevailing westerly winds across the Cape St Francis headland to sand dunes west of St Francis Bay.
These extensive sand dunes acted as temporary keepers of the sand until the sand was picked up by the Sand River in massive and episodic floods that moved tens to hundreds of thousands of tons of sand in a day or two. This sand was then transported through hyperconcenrated sediment flows into St Francis Bay, where a large sand delta had formed that supplied the beach with sediment.
In the 1940s and 1950s, the State – through an extensive public works programme – started a project of planting trees such as Acacia cyclops, well known to stabilise mobile coastal sand dunes, in order to stop the dunes from “moving ever eastwards”, thereby limiting coastal development. The planting of these alien trees 60 to 70 years ago has stimulated development along the coastline, including Oyster Bay and St Francis Bay.
The St Francis Bay Marina, which required the diversion of the Sand River northwards into the Krom River, was the nail in the proverbial coffin. These factors, particularly the diversion of the Sand River, has resulted in the interruption of the natural sediment supply from Oyster Bay to St Francis Bay, leading to coastal erosion on a scale that now threatens properties of beach-frontage home owners in St Francis Bay.
A second stop of the morning was the Sand River Delta extending into the Krom River, which involved the deposition of a massive body of sediment from the Sand River catchment in the Krom River, blocking the Krom River and removing access to the river front by several homes on the Krom River. The third stop was at the Sand River Bridge which has been washed away twice since 2011, effectively cutting St Francis Bay and Cape St Francis off from “the rest of the world”.
A walk up the bed of the Sand River, thick with rushes and sedges, with intriguing explanations of the transport of tens to hundreds of thousands of tons of sand down the Sand River, was a highlight. In June 2011 about 85,000m3 of sand (about 150,000 tonnes) was transported down the Sand River in a day, the equivalent of what the Okavango River transports to the Okavango Delta in a year! This massive movement of sediment caused a tsunami-like deposit of sand into properties along the Krom River.
The cause? The stabilisation of dunes and diversion of the Sand River in the 1980’s to create the much sought-after and priced-at-a-premium St Francis Bay Marina.
The proposed construction of a nuclear power plant along the coastline at Thyspunt, west of Thysbaai, was a topic of conversation on the week-end and discussions included the pros and cons of this technology and the proposed location of a massive infrastructure project like this on a soft landscape.
We came to see the vital importance of local input and good scientific understanding of landscape-level processes if a development like this is to be safe and sustainable.
It was an enormously enjoyable and thought-provoking weekend.
