Page 11 - Landscape SA 103

FEATURE

Plants laid out correctly before the team begins to plant.
Site five after treatment. Photo: Hans King Photo: Sean Altern

had completed a large portion of the gulley, and the existing gulley had become weirs. Palmiet initially requires flowing
alien vegetation clearing when, in 2013, much wider and deeper. water over the rhizome and stem until
we experienced heavy rains and severe the roots re-establish in the soil. Water
flooding. This increased peak flow rates of An examination of the soil structure was pumped in using the Vergelegen fire
water run-off and created gullies in many revealed why the erosion was so rapid and truck.
of the water courses. In some areas, rocks serious. The top 50 mm was reasonably
were washed out and blocked the natural resistant to erosion, but beneath it lay “This project has been a major
water courses flowing to the river, forcing deep, highly decomposed granite. Once undertaking, but it has ensured that we
an unnatural distribution of higher flows the erosion was deep enough to penetrate have controlled the erosion that would
to be channeled onto the estate. the decomposed granite, vertical erosion have had an extremely damaging impact
was swift. on the land,” says Naidoo.
“The resulting erosion was initially not
easy to see because the land was still There was the danger that a wide area Typical indigenous plants used
covered with vegetation. A wildfire in around the gulley, a large portion in the eroded area were the
January 2017 exposed the areas and signs of which is home to the critically following:
of damage could be identified; without endangered Lourensford alluvium
the standing vegetation to stem the water fynbos, could be covered by a deep layer Athanasia sp. (drier margins)
flows, the situation worsened during of weathered granite and silt. Approvals • Berzelia abrotanoides
the winter rainfalls. We immediately required in terms of the National • Berzelia lanuginose
brought in experts and in due course Environmental Management Act turned • Blechnum punctulatum
received reports from an environmental out to be a lengthy process and the • Brunia laevis
consultant, a specialist engineer and a erosion worsened with every rainfall. The • Carpha glomerata
wetland expert.” rehabilitation finally got underway in
August 2020. • Cliffortia odorata
There was agreement that without • Cliffortia strobilifera
suitable interventions, there would be Vegetation replanting • Elegia capensis
degradation resulting in “escalating and • Erica caffra
irreversible ecological damage and huge As part of the rehabilitation programme, • Erica quadrangularis
financial costs.” local indigenous vegetation was prepared • Freylinia lanceolata
for replanting after the erosion control • Ischyrolepis subverticillata,
Tackling erosion weirs had been constructed and other • Pennisetum macrourum
containment measures put into place. • Prionium serratum
In a massive undertaking, 30 erosion • Psoralea affinis
control weirs were constructed, sediment The team erected a 10m x 30m tunnel in • Psoralea aphylla
was removed, and rocks and other August 2020. Plants from the eroded areas • Psoralea pinnata
materials were placed in the water courses. were stored in the tunnel for replanting, • Pteridium aquilinum
while new plants were also propagated.
Of the five zones, section five was This aspect of the programme was • Restio paniculatus
particularly challenging. Specialist delayed when 120+ km/h strong winds • Wachendorfia thyrsiflora
engineer Hans King visited the estate lashed the estate in October 2020,
in 2017 to stabilise a 40m long gulley. damaging the tunnel and destroying Wayne Coetzer, MD of Vergelegen, says:
He noted “a strange, very narrow (about some plants. Nonetheless, many survived “Conservation and social responsibility
500mm) but very deep (about two metre) and more were propagated, and in 2021 remain at the heart of everything we
groove in the soil extending for maybe 100 replanting began. do. It is only by working together and
metres upstream of the gulley.” in partnership with nature and our
In addition, green, well-rooted palmiet surrounds that we can create a future that
A few months later, photographs revealed was gathered from a dam spillway is truly sustainable for future generations –
that the groove had become part of the stockpile and placed vertically in the humans, plants and animals alike.” LSA

Landscape SA • Issue 103 2021 9