Land-use and an ecological plan around the Bot Estuary.
A land-use and an ecological plan around the Bot Estuary is necessary as a first step in establishing a sound,…
The agricultural potential in Hawston article was written in 2017, and is more relevant today with the start of the Paddavlei rehabilitation.
Historically, the agricultural potential in Hawston was exploited with vegetable and crop production practised in the areas adjacent to the wetland below Paddavlei for many years. This is one of the very few areas in the Overstrand where this is possible without huge inputs.
In a narrow strip to the east of the Paddavlei drainage area there has been an accumulation of silt over thousands of years, due mainly to the very slight gradient of the Paddavlei. This has led to a sand-silt mixture which is deep and is rich in nutrients accumulated from the soils upslope from this area. The Paddavlei itself feeds seepage water into this area. The seepage water is supplemented by numerous well-fed seeps from the east.
This is generally a very marginal area for any sort of crop production as far as rainfall, the poor, generally shallow soils and generally poor nutrient status are concerned. Most of the rainfall is in the winter months and there are usually very dry hot summers. There has always been extreme variability in the annual rainfall in this area which would have further precluded any sort of stable crop production. However, the area to the south of the Paddavlei is very flat, with relatively deep sandy soils. All the rainfall in this area drains into the sand and this includes a large steep mountain area where the runoff also adds to the underground water table. This water is mostly blocked from seeping directly down to the sea by an impervious geological layer; instead this water, historically, created and maintained the Paddavlei, an open body of water, surrounded on the east side by wetland. The slow seepage of water from the south maintained this open body of water with relatively little change in the level through the dry summer months.
The Paddavlei was able to develop a Milkwood forest on the dry sand dune on the west side of the Paddavlei. This sand probably buried part of the more extensive wetland on the west side of the Paddavlei which now allows water to seep in under the sand dune. This water then feeds the deep-rooted Milkwoods and allows them to grow right up the sand dune.
The extensive seepage water maintained a water regime which is much better than expected, in this area through the dry years.
Crop production requires reasonably deep soils with a reasonable nutrient load and lots of sunshine. All these are in place in the area north of the Paddavlei. Spread south and north of the old Griqua church are numerous simple hand-dug wells which were then used to supplement the rainfall to grow crops in this area. Once the plants were established, they tapped into the relatively high water table in the area and did not require much additional water. The ‘lang erwe’ (long erven) of Hawston, used to feed the local and surrounding communities and constitute an ideal area for market gardening and to exploit the agricultural potential in Hawston, which still exists for cost production.
The huge Milkwood trees, very large Port Jackson trees and very tall reeds growing in this area are further evidence of an adequate supply of water and nutrients. This has been maintained through the last decade, in spite of the attempt to drain the water out of this system in 2008, through the sand dunes and into the sand dune area stretching to the sea. Thankfully this plan was aborted half way through construction but has presently altered the natural system of the Paddavlei Milkwood forest, which is now showing signs of stress. The engineering structures, partly put in place, have caused less water to arrive in the area north of the Paddavlei but the forest is fairly resilient and has maintained itself fairly well. Obviously the massive expansion of exotic invasive species, in the last two decades, especially to the south of the Paddavlei, has also severely reduced the water into the Paddavlei and significantly reduced the seepage water to the north of the Paddavlei.
Most of these problems can be easily fixed and have been reported elsewhere (Austin, 2017). A viable crop production area can be re-introduced on the erven which have been demarcated into the wetland area. With the re-establishment of the wetland area, the re-establishment of the Paddavlei as a stable open water body supporting a viable fish and bird population, the reduction of pollution entering this area and the removal of roads built into or across the wetland.
These areas need to be cleared of the extensive reed invasion. In the past, some farmers in this area used to dig ditches through the area, pack the reeds into these ditches and burn them. This helped to destroy the extensive root systems and returned the nutrients to the soil which then benefitted the crops grown here in the following years.
Once these areas have been cleared, it might be necessary to put in some agricultural drains in some areas. The high nutrient status of most of these soils need only limited amounts of additional nutrients. It is not desirable to promote nutrient flow into the wetland.
The handling of storm water flows through this area requires attention. The main south-north storm water flow down the old natural flow area has been dealt with elsewhere (Austin, 2017). The flow of water from the roads through this area will need additional attention to avoid erosion and flooding of the crop areas. This would normally be the job of the Overstrand Municipality (OSM) with their normal maintenance of the roads. Particular attention needs to be paid to not disrupting the seepage flow of water into the area. Some of the wetland areas have had extensive rubble dumped into the area, burying the soil, and these areas need special attention. Unfortunately, it is not easy to remove this rubble without changing the profile of the land and removing a substantial amount of the good soil as well.
The area which could be farmed is approximately 10.5ha with an expansion of 3.5ha potential area. With reasonable management by the plot owners, this area is capable of producing a great variety of vegetables of the order of 500 to 700 tons of vegetables. The idea is to promote a good variety of crops to minimise risk, minimise disease and grow companion crops. The ideal is to have a fully-integrated system with vegetables, fruit production, pigs, chickens and maybe ducks. All waste is to be composted and reused. The sandy soils require as much compost as possible worked into the sand to promote water-holding capacity and will replace nutrients taken off with the crops harvested from the area. This will lead to a viable, stable income- producing venture for a number of families. Obviously work opportunities will arise and this development could lead to being a stimulus for the whole area. The people involved will be a nucleus able to incentivise others to maintain the clean water flows and reduce pollution into the area.
Wind is a factor in this coastal area which generally experiences many days of high wind velocities. However the area in question is at least sheltered from the south-wester by being in the lee of the sand dune on the west side.
Grain crops are not recommended on this relatively small area which is capable of producing much higher income vegetables per unit area.
The establishment of a co-operative is a good idea:
There is a small market for the produce from within the Hawston area and a ready market for farm fresh vegetables within the Overstrand area where most of the vegetable products have to be brought in with the attendant transport costs. There is very little competition from home-grown vegetables within the area or from nearby areas.
The re-establishment of the agricultural potential in Hawston as an intensive vegetable production area will not only supply many work opportunities but will also harness the skills required from within this area. Initial guidance will need to be supplied and some assistance given in repairing some of the engineering mistakes of the recent past which led to the destruction of the area as an agricultural production area. It has already been established that there is keen interest in farming this land once the engineering structures that caused the extensive reed invasion of the area are removed.
The agricultural potential in Hawston can be exploited at relatively low cost and establish a viable market garden within an area where unemployment is very high.
Michael Austin
HDA (Hawston development Association) and Research officer for PEG (Paddavlei Eco-Group)
References
Austin, 2017. Paddavlei Ecosystem Rehabilitation report. HDA, Hawston
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