Sand dunes and the St. Lucia estuary issues

 Greetings to all who read here. It is Thursday  20 October 2022 and WE need to do something soon, coz the problems are growing faster than the solutions are being discussed, never mind the implementation issues.

The April / May 2022 floods have caused many different problems, and in my mind, the biggest problem for our fish breeding grounds is the vast quantiles of silt that has dropped out at the most inconvenient places for nature to have any chances of restoring any sanity to the now dysfunctional natural breeding grounds for many marine fish species and other creatures like crabs, jellyfish and prawns that used to flourish in our local ecosystems within the Greater St. Lucia Wetlands Park.

One needs to remember that the St. Lucia Estuary Mouth was closed when these flood waters struck our waterways in May 2022. These many different waterways, in the area each have distinct and separate issues. some of these water ways  that matter more are 

1. The Northern sections of Lake ST. Lucia
2. the tidal interaction channels between The Northern sections of the lake and the Ocean itself
3. Hells gate and the Nibela peninsula / False bay lake zones
4. Makataan swamp forest and adjacent fresh water input zones
5. The immediate Mouth Zone where the Umfolozi and Mzunduze river interact with the Tidal interaction channels as in 2 above
6. The tidal zone at the mouth and tidal interactions of
7. (a) the Umfolozi river
8. (b) the Umzunduse tributary of the Umfolozi river
9. the Umfolozi flats and associated banana farms on both the North banks and South Banks of the Umfolozi River
10. the Monzi sugar lands and associated flat lands
11. The Umfolozi flats
12. the Sokhulu sand flats
13. the Mapelane  swamp lands
14. Teza Pan and associated waterways

another issue to consider is that the lake water levels were already a bit high when the big rains in May 2022 struck our waterways with a rather intense speed. The speed that the Umfolozi River flood waters entered the northern sections of the lake needs to be properly understood, as does the vast quantity of river-born silt that dropped out at the zone where the Narrows opens up and fans out into the Sothern edge of lake St. Lucia. 

 

This caused a rather large un-natural blockage to grow into a nasty problem. coz when the mouth opened due to rising flood waters, the water within the Northern sections of the lake was trapped, and did not have the energy to remove the waterborne sediments that had accumulated in the system, at the spot where the water slowed down,  due to the GEF 2017 project, which connected the Umfolozi river directly to the St. Lucia lake systems, bypassing the natural silt traps of the Umfolozi flats, the Monzi flood plains and the other lower areas near Sokhulu and Mapelane. this silt dropuut was hectic.

So the vast amounts of silt that came along for the ride in the April / May Floods and dropped out at various problem zones needs to be clearly understood, as this silt is now problematic in many different areas. At the Mouth of the ST. Lucia estuary, the reeds, sedges, grasses and other riverine plants have enjoyed this silt and are now doing very well. These are all growing in the mud flats, which should be sand flats,  These well-established plants are now acting as a final sand arrestor, at the western end of the fast-growing sand dunes that are getting very problematic. this wind born sediment is joining the water-born sediment and forming a distinct top layer which is fast turning the mud layer into very hard bentonite-enriched  sand sludge that will soon be setting into very nasty river-born sediment and other  stuff.  

What would this be called? we need some scientists to come and explain more about this  cement-like stuff to the public so that the public can start to use this information to force the issues and ensure that we get government interventions and make sure that our fish breeding grounds are repaired and made functional before too much damage is caused, coz with ZERO juvenile recruitment there will soon be no fish. If our fish breeding grounds are not functional there will be no juvenile recruitment.

So please help the 4u2fish campaign to put pressure on the relevant political structures so that the problem can be addressed as soon as possible. read more at our FB Pages facebook.com/4u2fish