Monday, December 12, 2011

St Lucia Estuary - Water Update

iMfolozi River flowing into the ocean taking millions of metric tons of sediment dumping it onto the Tugela Shelve and silting up the rocks and estuary/river mouths. This is mainly due to sugar cane farming that turned low lying flats with reeds, swamps and wetlands into agricultural land. The process is aggravated in the catchment area through poor soil control. Government is claiming that they inherited a poor Government in a post Apartheid election, but they neglected job creation that maintained the roads, storm water drainages and top soil management.

The Estuary system is a low energy system that is aggravated during dry spells. High energy flash floods bringing down million metric tons of top soil with out running through various filtering systems  clogs up the lake and Estuary. The low energy drainage through rainy season and tidal interaction cannot clear the sand bar built up. Other than high seas and Cyclones only mechanical intervention can clear the sediment built up.

Poor management over the past 11 years and drought has played havoc on marine life since St Lucia Estuary is the only functional system between Kosi Bay and Richards Bay Harbour. Said Harbour has not been well maintained either in currently experiencing high pollution levels due to poor infra structure management and wind directions that prevails during dry spells. 

None of this is going to change soon with the iSimangaliso Wetland Park Authority deploying capital draining hard surface development that not only stops a eco system from functioning by it self, but increases pollution and hamper animal migration.
The new paved parking areas is a huge improvement of the neglected dirt parking areas, but it effectively increases storm water drainage, limits vehicles per parking area and changes the dune area and blow out zones for ever. a Blow out zone is the area where the wind will blow accumulated sand out and form the vegetated dune range. This paved development has effectively now established the dune are and the ever altering dune areas has now been fixed by man made abstractions.  This will have a push back effect on the sediment and a larger sediment built up in front of the Estuary mouth will lead to longer periods of closure.Thus leading to a decrease in spawning time and less and less fish will breed every year.

All in all man made intervention spells the death of our planet.

by Petrus Viviers
081 342 7371

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