The project

The background

Over 75 years ago the valley between Middle Beach and Bushman’s river was used as a camping ground for holiday makers who lived between the two rivers and Grahamstown, when they originally came down in their wagons. This valley has been known as “Dry Bones Valley” for several generations. The water table was high and documents indicate that there was a well and this water was available for the holiday makers. Records confirm there was a waterhole for the animals which was maintained when the Joan Muirhead Reserve was founded in the 1970/80 period.

There was little vegetation in the base of the valley and the prevailing winds used to take what little “blown” sand there was through this valley. The road to Middle Beach was then built and this then put an end to the wind bypass. The Bushman’s river was relatively fast flowing and hence little silting took place, and most of the sea sand from the Bushman’s side was deposited in the river. Hence there was no sand dune at the Bushman’s river end of the valley and in fact the river flowed along what is now Westbourne road and then at right angles out to sea. The explanation of the build-up of sand in the last 30 years is explained. The fact is that there was little sand in any volume blown down Dry Bones valley in the past, as there was very little sand build-up.

In fact there are records in 1992 which show that the silting of Bushman’s river was a growing concern at that time and you will see an extract taken from the 1992 Estuary Monitoring (figure1).
Figure 1 – Extract from the 1992 Estuary Monitoring.
Our consultants advised us that the wind dynamics of DBV had changed, as both sides of the valley had substantially more vegetation than in the past and, with the addition of the housing developments, have caused further loss of wind velocity. Hence wind speeds are now significantly lower than in the past. Because the wind velocity is much less the sand will not move as before. Just removing the vegetation at the base of the valley would not restore the valley to what it was, and there is a high risk that the sand volumes will not resume blowing though the valley, as they used to. Furthermore, much of the sand dune has formed west of the valley in front of the houses, and has not been entering the valley but presenting as a large transverse dune. They also advised that the dune may continue to migrate, in this same way, as has been monitored over the past years. It has been very evident this year that the wind direction changes have caused Westbourne Road to be threatened with closure. All these problems have been made very clear over the last few years and, hence, many other options had to be considered. These options have been thoroughly studied by KSDNA with their Consultants.
Lands End Road was opened for development in November 1989. Homeowners along this road and valley chose this location as it has reasonable access to the beaches at both ends, and with the beauty of the nature reserve on the opposite side. These residents are determined to preserve the valley in which they have built their homes, and indeed would like to see the nature reserve enhanced and maintained and the natural beauty of this valley improved. Once the rehabilitation of the sand dune is completed the KSDNA would like to support the management of the Nature Reserve and its’ fauna and flora to re-establish this beautiful area of Kenton.
It should be mentioned that the Environmental Authorisation issued by DEDEAT on 11th August made it very clear that the vegetation in Dry Bones Valley should be left undisturbed as far as possible. Our enquiries, since this Authority was issued, show that this has been received with overwhelming support by all communities. We must manage and improve the environment as it has been evolving as a result of human intervention, and with professional advice and experience we can certainly achieve this most satisfactorily, and plan for the future.
The sand dune has now become a very ugly area. Impossible for elderly to climb. The turning circle becomes a lagoon. The large beach area by the river is less used as access is difficult. The lack of washroom facilities must also be rectified as this area becomes increasingly contaminated without facilities for the beachgoers. Clearly this area must be provided with a suitable Washroom .

Growth of the Sand dune at Bushman’s River-Mouth

The construction of over 50 dams, beyond the Kenton bridges, and jetties in the catchment area of the river constrict the flow of the river, and are the main reasons why the flow of this river is steadily slowing. As a result of the reduction of the speed of the water flow, the river has slowed, and this reduces the waters’ ability to scour the bed and maintain a deep channel. Slower flowing water also deposits more sediment. Silting from the land has increased the area of sand banks and vegetation on the sand banks stabilises them. The factual situation is that man has created these changes and we must therefore manage the outcomes, and prevent any resultant problems recurring because of our failure to manage them.
Over the years the incoming tide flow has become increasingly stronger than the outflow from the river at low tide and, hence, the steady, but rising escalation of silting.
There is around 100 000 to 300 000 m3/year (1 m3 = 1.6 mt) of sea sand moving along the shore line. The incoming tide carries the sand, in suspension, as far as 3.5 Km inland but very little beyond this. The existence of the rocks on the Kenton side of the river mouth and the long unhindered beach on the Bushman’s side provides a funnel that causes around 5 500 m3/year of sand to be carried inland. The silting in the first 3.5 km of the river is mainly sea sand, river silt diminishes to very little towards the river mouth to the sea.
Hence, the serious silting of the river arises from approx. 3.5 km from the mouth due to sea sand being deposited by wave driven currents. Because of the very nature of the mouth of the river, where there are rocks causing the river to diverge, much of this sand is deposited at the mouth. There is now a wide, flat inter-tidal zone at low tide; this dries and is then blown by strong westerly winds towards Westbourne road. This has resulted in the sand dune we now see today, which will continue to grow as there is always sand available at the mouth. Notably, this sand does not come from the beach on the Bushman’s side. Much of the dried, airborne sand falls into the river. It is the sand from the river being deposited as the tide enters through the mouth on the incoming tide. The prevailing wind blows direct on this sand, propelling it inland and hence the build-up of the sand dune, which has increased in the last 30 or so years.
It is hoped that the Bushman’s river will be dredged in due course. While this will speed up the river flow and will reduce the sand deposits to some extent, it will not prevent the sand from the sea continuing to cause this sand movement.
The present growth of the sand dune is increasing each year by approximately 3,000 cubic metres which is part of the 5,500 cubic metres of sand deposited by the river annually.

Understanding the Sand Dune and the options

Some 4 years’ ago it was determined that an independent study should be carried out and PRDW were appointed to carry out a preliminary study of the sand dune. This was followed by a thorough study of Bushman’s River in order to address the silting issue, to understand the cause of the problems and to obtain the recommendations to manage these in the future.
Chester Wilmot recommended that the vegetation along the base of Dry Bones valley be removed and allow the wind to carry the sand along the valley. The outcome of this initial study was that this could well happen but it would not solve the problem. The problem would just be moved from one end to the other end of this valley, with many other anomalies likely to develop during this long process. The flow of the sand would still have to be managed. There were existing sand dunes arising from wind blowing in the opposite direction. Middle Beach road would block the path and hence, eventually any sand dune that evolved at the other end of the valley would have to be moved into the corner of Middle Beach. Clearly, this was not a long term solution and would be unacceptable to the residents in Lands End Road. Over time it would be no less costly.
There was some belief that the sand from Bushman’s river would benefit the sand dunes between Middle Beach and Main Beach as it was suggested that these were deteriorating. The fact is that these sand dunes have not deteriorated and these are being maintained by the sand from the sea as it has in the past. (There is a small area near Middle Beach which is being eroded because of man-made interventions, but this is readily managed). There is no sand dune erosion beyond Middle Beach, after the launch area for the fishing boats, and this is not an issue of concern for some of the community.
Following the study of the river, a complete understanding of the Sand Dune and its’ future growth, was clear. The answer was to create a solution for the ongoing future build-up of sea sand. The objective was therefore to reduce the Sand Dune to an acceptable size and then manage the future flow of sand.
To achieve this many options were considered. Moving the sand back into Bushman’s river would probably cause more problems than solve them. Trucking would be costly in many respects and environmentally unsatisfactory. Conveyor systems would be costly and inefficient and equally environmentally unacceptable. A better solution was found using a slurry system which would have removed most of the dune sand to the beach between Shelley and Middle beaches and most of this sand would then be taken out to sea. The fact was that all the alternative solutions which were considered required the removal of a significant part of the Sand Dune, and this was the main element of the cost. Could this be avoided? The answer was found, and this meant that the Consultants were able to complete the recommendations which are covered in detail below. They not only provide a long-term solution but at a cost which was less than one third of the cost of the original Dry Bones Valley proposal.
The Consultants recommended that we look at the similar problems experienced at Hout Bay in the Cape. Their solutions looked very promising and, after very positive discussions about their operations, we asked our leading Coastal Engineering and Environmental Consultants (both of whom have been working on our Bushman’s River problems for the last 4 years) to come up with a detailed plan. After completing a detailed aerial survey, this has now been finalised and has proven the most appropriate. It is the least costly, providing a long term solution to maintain this area at minimal cost, and meets all the criteria for this attractive and important area of the river. The problem of sand deposits persist and this proposal provides the solution.

The Solution recommended by the Consultants


Residents of Kenton have been adversely affected by the build-up of dunes and the problems associated with the accumulation of sand for many decades now. The development of a large dune system at the Westbourne Road Circle (WRC) in Kenton has been the subject of a number of studies by both CES and PRDW. 

An intervention is becoming urgent as the estimated rate of sand movement has more than doubled, from approximately 0,7m per month in 2013, to 2m per month in 2020. The local Municipality has, unfortunately, been unable to address the problem, thus the residents formed the Kenton Sand Dune & Nature Association (KSDNA) to assist with finding a solution.

In the intervening four years the KSDA have investigated a number of options, and noted the successful implementation of sand removal and rehabilitation of dunes, associated with a similar problem of sand accumulation, in Hout Bay. The KSDA then approached PRDW and ES to undertake further investigations and to develop a similar scheme, and to confirm whether this would be feasible as a long-term solution in Kenton.
This report covers aspects related to the revegetation and rehabilitation of the remaining dune system, and for more technical information the reader is referred to the PRDW report. Dr Ted Avis was invited to develop a rehabilitation and revegetation plan for the relocated dune. The overall objective is to eliminate the nuisance factor associated with windblown sand, improve access to the river and beach, improve recreational amenities and create a vegetated dune ecosystem that attracts wildlife and is both aesthetically pleasing and stable. This will be achieved through re-profiling that sand around the turning circle, by reducing the height of the sand dune by pushing sand upwind towards the river, and then to stabilise the mobile dune.

Long term management of the Sand

The effect of the stabilized dune will be to prevent sand from migrating over the dune towards Dry Bones Valley, instead it will continue to accumulate in front of the stabilized dune. The accumulated sand will be taken from the dune by a small loader (see picture) and then offloaded into a suitable vehicle for transport to Middle beach. This will happen, periodically, in quantities of approx. 75 cu per day.

The access path from Westbourne Road to the beach will be widened and wood chips laid for the small loader that will move this sand from the beach. The sand moved to Middle Beach will be readily dispersed by the tide and will represent a very small percentage of the sea sand that moves on this area daily.

Revegetation and rehabilitation plan

The most effective long-term method of dune stabilisation is through the planting of vegetation, generally self-maintaining, as coastal vegetation is adaptive to the harsh conditions to which it is exposed.  It plays a very important role in binding the sand, thus creating a self-sustaining ecosystem, with minimal maintenance requirements, which is the ultimate goal. Once the bulk earthworks have been completed and the dune has been reformed and rebuilt, there are a number of measures which must be put in place in order to stabilise the dune for re-vegetation, such as establishing porous dune forming fences (preferably shade cloth wind nets) across the width of the dune, at 5m intervals in the upwind area (which will also prevent people trampling on newly established vegetation). Brushwood is also recommended in areas not fully exposed to the dominant westerly winds, and in areas of lesser wind exposure (hollows/flat areas), surface stability can be achieved by using mulch, which assists with retention of soil moisture and provides protection for seedlings. Wood chips can be used for surface stability in the proposed pathway.

Irrigation is also required to assist with the establishment of plants in the early stages of their growth, so they can evade moisture stress during their establishment period. It greatly increases the survival rate of planted seedlings. Typically, irrigation will be required during the hot and dry months and possibly for the first two years only. It has been confirmed that a borehole can be sunk on site and suitable water for irrigating plants is available.

The Authorisation

The DEDEAT authorisation given to the Ndlambe Council.
On 11 August the Department of Economic Development, Environmental Affairs and Tourism (DEDEAT) issued the Notification of Environmental Authorisation for the Proposed Coastal Sand and Infrastructure Maintenance Management Plan within the Ndlambe Local Municipality. This was delayed by three months, due the effects of the lockdown we all experienced, and we were delighted to see that the recommendations by the Municipality’s Consultants, Aurecon, to DEDEAT for our Kenton sand problem were almost identical to that proposed by our Consultants, PRDW/CES.
The recent, significant movement of the Sand Dune emphasises the wisdom of the Proposal put forward by the Consultants, to keep the sand away from the roads and properties and to preserve the natural vegetation of the valley. The re-profiling and re-vegetation of the Sand Dune incorporates vegetation similar to that in existence all along the Westbourne Road and, thus, the Rehabilitation plan ensures that the natural vegetation and beauty surrounding the mouth of the river will be conserved.
Our Environmental and Social Advisory Consultants, CES, are in the process of finalising the KSDNA agreements with the Municipality and completing the final submission of the Proposal for the Municipality to receive approval from DEDEAT. This is required to ensure that what we do is fully compliant with the various and lengthy conditions attached to the DEDEAT approval. Such conditions are standard practice to ensure that any and all actions are done so responsibly, and in a manner that minimises any potential negative impacts. This is achieved by preparing a detailed environmental management plan. Dr Ted Avis, MD of CES, studied coastal ecology at Rhodes and lived in the Eastern Cape for most of his life. He is completely aware of the ecological changes to the Kenton environment, and its’ challenges, having visited the exact site for annual first year undergraduate botanical field trips. Ted is closely associated with Prof. Roy Lubke, who appreciated the need to address the sand movement problem in the mid-90’s. Roy was also instrumental in getting the Joan Muirhead Nature Reserve founded in the late 1980’s. Prof Lubke published a very interesting paper on the vegetation of the Joan Muirhead Nature Reserve in The Naturalist in 1990. So it is clear that our consultants not only have a very clear understanding of the situation at Kenton, but also a strong commitment to our area.

The contract

The contract between KSDNA and the Ndlambe Municipality and its funding.

The Contract to re-profile and re-habilitate the Sand Dune

The KSDNA will be entering into a contract to complete the Kenton Sand Dune Maintenance Management Plan which will be strictly in accordance with the DEDEAT approved and authorized Plan as covered above in the ‘DEDEAT Authorization’.

This contract covers the re-profiling of the Sand Dune and the creation of a new frontage for this sand dune that will prevent the new, accumulated sand from blowing inland.

The contract will cover the establishment of all the re-vegetation of this re-profiled sand dune to ensure its’ stablility, and will further develop the indigenous vegetation that exists in Dry Bones Valley and along the frontage of Westbourne Road.

The Funding of the Contract with the Municipality

The funding from KSDNA has covered all expenditure incurred during the last five years, and will continue to fund the costs for the total completion of the project. It is estimated that it will take a further three years for the vegetation to establish itself, which we hopefully predict for 2024.

A synopsis of the funding covers the total costs of all preliminary investigations undertaken in the last five years, the preparation of the Proposal, and all survey work during this period and in the finalization of the project Proposal. It covers the consultants’ work in finalizing project approval with DEDEAT and the overall supervision of the Contract to the required Environmental Standards.

The project itself, as described above, and the on-going management of the project, will have taken fully 8 years to bring to completion.

KSDNA will be delighted to have helped in re-establishing Kenton as one of the most beautiful places in the Eastern Cape, and for the community to enjoy this ‘gem’ in the years to come.

Consultants proposal and the implementation of the Sand Dune Project

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