https://dailyfriend.co.za/2020/10/23/st ... -solution/
The symposium organised by the iSimangaliso Wetland Authority from 13 to 15 October was remarkable for the consensus that the sealing of the estuary mouth is the critical problem facing the region.
Asked to list critical issues, all nine breakaway discussion groups, consisting of 80 participants, listed the estuary first. Given the diversity of interests represented – the iSimangaliso Wetland Authority itself, Ezemvelo KZN Wildlife, traditional leaders, scientists, ratepayers, the local tourism and hospitality industry, sugar farmers, small-scale community farmers, traditional fishermen and line anglers – such a level of agreement was remarkable.
It certainly impressed iSimangaliso CEO Sibusiso Bukhosini, who remarked on the extraordinary vibrancy of group discussions as well as the considerable agreement on most issues raised.
But genuine community consultative processes are slow.
Bukhosini himself may well have been disappointed by the symposium’s rather limited immediate outcome. It agreed to set up a stakeholder working group, comprising all the interests present, to determine the way ahead. Given that this still has to be established (today is the closing date for nominations) and its terms of reference agreed, the optimal moment for breaching the estuary mouth – to coincide with the first floods of the summer, expected imminently – might be missed. Bukhosini could promise no more than that there was budget available and that it had to be spent by March 2021.
The fact is that the St Lucia estuary is in a critical condition. What was until recently South Africa’s greatest estuarine system has been sealed from the ocean since 2002, with only a brief breach between lake and ocean for five months in 2007. The problem is the result of management decisions and human intervention and the obvious solution – an artificial breach – is a tried and tested management technique which needs to be urgently reintroduced.
Estuaries are very special environments in which life has adapted to a changing mix of salty seawater and freshwater. Such environments are associated with mangroves and other flora and fauna adapted to thrive under conditions of varying salinity. A healthy estuary is typically clean and mud-free, thanks to the scouring effects of rivers and ocean tides. Like all estuaries, St Lucia had a thriving fish and bird population, complemented by a big population of hippos and crocodiles. The estuarine prawn nursery has previously been described as the ‘most productive’ on the South Africa coast.
Drowned in mud
But the St Lucia estuary has drowned in mud. This has been deposited by the Mfolosi River through four points of entry including the three back-channels which were previously closed to prevent increased sedimentation. The river was artificially linked to the estuary in an attempt to deal with drought conditions prior to 2016, a problem aggravated by intervention which prevented any water entering Lake St Lucia within the mouth area. These conditions provided the opportunity to remove the ‘dredger spill dune’, utilising the material to construct a ‘dam wall’, completely separating the ocean and the lake. This was a huge mistake and it cannot be understood how consultants, management and scientists allowed it to happen.
St Lucia was proclaimed a United Nations Educational Scientific and Cultural Organisation (Unesco) World Heritage Site in 1999. The proclamation includes much more than just the estuary and covers a system of lakes and wetlands which run up the Zululand coast to the Mozambique border. But the 70km-long estuary was singled out by Unesco as one of three ‘outstanding natural phenomena’ which justified World Heritage status. Unesco remarked at the time:
‘One (of the outstanding features) is the shifting salinity states within Lake St Lucia which are linked to wet and dry climatic cycles with the lake responding accordingly with shifts from low to hyper-saline states’.
No longer a functioning estuary
The problem is that there is simply no longer a functioning estuary. The unique estuarine features of Lake St Lucia have evaporated like dew before the morning sun, leaving an expanse of mud and reeds, and in some areas a much less diverse fresh-water lake. A report to the Living Lakes Foundation last year summarises the present condition of the area:
‘Salt-reliant plants have died including the mangroves and organisms dependent on them have become extinct. Excessive reedbeds have flourished and expanded in these fresh-water conditions … the natural pendulum shift between fresh and saline water has ceased to function … fish that rely on the estuary and lake … are therefore unable to do this while other fish that need to return to the ocean are landlocked’.
Lake St. Lucia joined the International Living Lakes Organization in 1998 under the threat of dune mining for heavy metals. Although the dune mining threat was beaten off, it has been replaced by the issue of estuarine collapse. Representations have been made recently to have St Lucia declared ‘a threatened non-functional lake under its present dire condition’.
Presentations at the symposium by former iSimangaliso scientist Ricky Taylor and Nelson Mandela University estuarine scientist Professor Janine Adams confirm that the estuary is simply not functioning and hasn’t worked for a long time. Both pointed out that estuarine fish species like grunter and mullet are no longer found in the lake. Adams says that recent research has found that invasive fresh-water species (duckweed, snails) are driving out locally adapted estuarine life. She adds that ‘fine suspended sediment’ is now found all the way up to South Lake’. Hippos and crocodiles are no longer found in ‘The Narrows’ – the five-kilometre stretch running from the mouth to the main lake – where they were abundant only five years ago.
Since its proclamation, the estuary has been under the management of the iSimangaliso Wetland Authority, a purpose-established agency which reports directly to national government. It had previously been managed by the provincial conservation authority, Ezemvelo KZN Wildlife, which had taken a very active approach to managing the mouth. Through dredging, the mouth was kept open ninety-two percent of the time, thereby preserving its estuarine condition. In the 1990s, when dredging and artificial breaching were still being done, the National Research Foundation’s Estuary Information System described the condition as ‘good’. Under iSimanagaliso, however, not dredging and thus keeping the mouth closed has become the default management policy.
First sealed from the sea
The estuary was first sealed from the sea in 2002 to protect it from spillage from a shipwreck. The 31 000-tonne freighter Jolly Rubino had caught alight and then gone aground dangerously close to the estuary. The decision to artificially close the estuary mouth was widely approved at the time. However, although it was stated that the new berms and closures would be removed following clearance of the potential oil spill, this never happened. The estuary remained shut. Damaging though this was, the most harmful intervention was yet to happen.
The Mfolosi mouth had been kept separate from Lake St Lucia, by dredging both at the mouth and further back, in ‘the narrows’, since 1952. Large amounts of dredger spoil were deposited in the southern part of the estuary, in the process reinforcing the levee which redirected the river. The decision was taken to remove the levy and pump the dredger spoil into the sea to be dispersed by the current. The iSimangaliso Wetland Authority management of the time did not like the existing arrangement, referring disapprovingly to ‘excessive dredging in the narrows’ in a 2011 Information document.
Funding was obtained from the World Bank’s Global Environmental Facility (GEF) which put up US$9 million between 2009 and project closure in 2017. Other funding came from the South African government and other donors, notably the government of the Netherlands. Although the funding was designed to cover many aspects of sustainable development, including scientific studies, education, community and small business development, the central focus was on removing the dredger spoil. But this part of the programme was a disaster.
The process of mechanically pumping the dredger spoil into the sea commenced in May 2016 and immediately ran into problems. The task was beyond the capacity of the equipment available and the situation was not helped by iSimangaliso’s refusal to allow the contractor to abstract fresh water to flush the spoil down the 300 mm pipe. Attempts to pump the spoil were quickly abandoned and mechanical excavators deployed instead.
The problem was that instead of being pumped into the sea to be dispersed by currents, the dredge spoil was dumped on the beach at more-or-less the point where the estuary mouth would ordinarily breach. The result is that the estuary and the sea are separated by an artificial wall which nature is highly unlikely to breach without human assistance. A satisfactory explanation for transporting the spoil only halfway to its obvious dumping point in the ocean was never given by either iSimangaliso or the World Bank. Unesco too has been entirely silent on the matter.
Dredge spoil dumped on the beach
The volume of dredge spoil dumped on the beach is easy to underestimate especially if viewed from ground level on the Lake St Lucia side. But, according to the World Bank’s 2017 Project Closure document, the volume dumped totalled 140 million cubic metres. If this volume of mud and sand were arranged in a cube, it would be one hundred and twelve metres along each side. That is approximately one third of the height of the Empire State Building in New York and almost exactly the same height as one of Durban’s tallest buildings, 320 West Street.
The initial hope was that a natural breach, brought about by summer flooding, would re-link the estuary to the sea. But the volume of spoil is too great to make this a realistic expectation. Instead, each wet season exacerbates the problem by dumping more sediment, thus reducing the velocity of floodwaters attacking the artificial wall from the Mfolosi River side.
Those counting on a natural breach have been reduced to suggesting that the solution is a replay of 1984’s Tropical Cyclone Demoina which washed away much beachfront and the dredger harbour in the estuary. But Demoina is described as a ‘once-in-a-hundred-year storm’ and was hugely destructive. The cyclone killed 242 people (60 in South Africa), left tens of thousands of poor rural people stranded and damage valued (then) at R100 million. Hoping for a replay is both morally indefensible and no sort of management strategy whatsoever.
St Lucia is said by the authorities to represent eighty percent of the sub-tropical estuarine environment in Southern Africa. But this rare and beautiful natural phenomenon is not the only casualty of a management misstep. The local tourism industry is heavily dependent on offering an estuarine experience, involving viewing hippos and crocodiles, especially to foreign tourists. Prior to the introduction of travel restrictions to combat Covid-19, foreign tourists made up eighty percent of the market. Without this offering, many of the 13 300 direct local tourism jobs are at risk. Many local people are already struggling to put food on the table. Failure to revive the estuary would come as a final blow to many.
Also at risk are upstream agricultural activities. The backing up of the Mfolosi River behind the artificial wall has affected commercial sugar farms through flooding. Farmers affected include three land-restitution beneficiaries.
Impact of back-flooding
Land restitution beneficiary Amanda Maphumulo received her farm in 2008. It was not easy to start farming in the middle of a recession, she says. But those difficulties are dwarfed by the impact of back-flooding since 2016. Maphumulo says she has lost eighty percent of her arable land to water inundation and with it, eighty percent of her crop. ‘We have inherited mosquitos, crocodiles, hippos and reeds’ she says. Debt is piling up and she doesn’t know if ‘there will be food on the table tomorrow or whether it will be possible to pay (her) employees’. She has already retrenched seventy-five percent of her workforce and says that the last four years have been ‘an emotional rollercoaster’.
The Sokolu community at Maphelane on the southern edge of the estuary have also been flooded out. Sokolu’s induna, uBaba Petrus Mlaba, says his community with its 300 farmers are unable to plant vegetables, bananas or sugar cane because their lands ‘are under water’. Ancestors’ graves are also inundated. Mlaba argues that the community’s economic and social future hangs on a knife-edge. He says the community previously wrote to the minister and received a response saying that there is ‘nothing to prevent the breaching of the mouth’. He told the symposium that he cannot understand why there has been no action.
Decisions about the mouth of the St Lucia estuary and its interaction with the Mfolosi River have been based on commissioned scientific research, funded by the World Bank’s GEF grant and presented in 2012. The objective was ‘to restore the natural hydrological and ecological functioning of this important system’. There is no reason to doubt the integrity of these studies but the subsequent management measures have turned out to be a recipe for disaster. It would seem that the original terms of reference excluded the possibility of artificially breaching the mouth and dredging the narrows.
No need to wait
There is no need to wait for a further round of scientific investigation. iSimangaliso CEO Bhukosini argues that ‘the GEF research’ was not a waste of time. It ‘generated valuable information and knowledge, without which we would not be where we are now’, he argues. But, Bhukosini argues, science evolves. ‘Certain issues may have been overlooked at the time. It is our responsibility to identify these and come up with solutions,’ he says.
For the majority who gathered for the symposium, an artificial breach is the obvious short-term solution. Beyond that, the mouth requires active management, informed by ecological science and community opinion. The establishment of the stakeholder group, decided on by last week’s symposium, is a first step in that direction.
