Silt from the Umfolozi River is a problem !!

Greetings to all who read here. 

My name is Frankie2Socks and I need your support in our efforts to restore functionality to the St. Lucia estuary and lake systems within and adjacent to the iSimangaliso Wetland Park world heritage site in the Umkhanyakude district municipality of KZN South Africa. 

 The main problem in returning our wetlands and related waterways to functional status is the vast volumes of silt that has dropped out of the Umfolozi River flood waters over the years that the St. Lucia estuary and the Umfolozi River mouth were treated as a single combined unit. 

 In the post-GEF 2017 PROJECT era an exceptionally large volume of the sediment in the Umfolozi River flood waters was thus deposited at the northern edges of the narrows just South of Makakatana Bay Lodge, closing the intertidal water flow path, which are the fish migratory routes between the Indian Ocean and their semi freshwater breeding grounds.

This closure of the intertidal flow channels between the ocean and the marine fish breeding grounds needs to be addressed. 

This sediment / silt from the Umfolozi River now needs to be mechanically removed and placed outside of the intertidal water zones of the St. Lucia lake and Estuary systems. When asking around about the true volumes of Umfolozi River silt and sediment that went under the bridge on the N2, just South of Mtubatba I discovered that nobody appears to be measuring the sediment loads of the Umfolozi River flood waters. The river sediment is a really nasty issue. The Umfolozi River sediment, silt and flood debris must all end up somewhere. 

During the periods when the two systems were actively connected, large quantities of sediment and flood water debris ended up flowing into the Lake St. Lucia basin through the St. Lucia narrows. 

 The St. Lucia narrows has been closed out and silted up many times over the existence of the Greater St. Lucia Wetlands and surrounding rural areas. There is ample evidence of these past floods when scientists take a deep look. This time it is a bit different. The issues associated with global warming and changing weather patterns need to be put into perspective. 

Poorly managed agricultural practices and large-scale soil erosion due to landscape changes are prevalent and then there are the natural changes in animal migration in, and outside our many parks as well as human development and expanding rural populations. 

 There are truly many varied issues that have contributed to the extremely high sediment and and silt loads of the Umfolozi River flood waters. That being said, Just how much silt has come down the Umfolozi River ? 

To the best of my knowledge nobody has been keeping records of these issues. There is thus a problem in explaining how much sediment has been deposited within the greater St. Lucia wetlands region, including

•  the UMfolozi Flats, 
• the Sokulu farm lands and the 
• Umzundze swamplands. 

 Unfortunately, this silt and sediment has not been evenly distributed over the area, but has dropped out at key focal points where the water flows down for any reason. Within the mfolozi flats there are a number of such sediment deposit points, where some have caused major water flow changes, resulting in changed water flow paths and other nasty long-term changes to the general landscape. 

This has meant that sediment has reached new areas and caused new problems for farmers, and in some cases folks houses are still underwater in  September 2022. These silt deposits within the southern sections of the park from Mapelane to River View are scattered accross the landscape. 

In the Sokulu area farmers are still flooded out coz of the vast number of blockages in the Umsundze River flow path. 

 In the central St. Lucia areas from the mouth, moving north, these silt deposits are kind of levelled out, and flat, but at the specific zone where the river water collides with the lake water, there is a truly troublesome silt drop out zone. 

This nasty silt dropout zone at the northern edges of the narrows is substantial. This Heavy silt dropout zone has caused a rather high dam wall that now separates the lake system from the estuary system, preventing any intertidal actions betwen Lake St. Lucia and the Indian Ocean.

 This introduced silt dam wall at the top-end of the Narrows is not the only problem here. The entire  River narrows is silted up, the mouth area of the St. Lucia estuary is silted up. Nobody can tell us just how much silt needs to be removed. The numbers are scary, coz when we did rough guesswork,  and used those estimates, the answers had an awful lot of zeros.  

We did an informal science experiment to estimate  the silt load. We filed up some two-liter cool drinkemties with raw River water. Left them in the cupboard for a few days then evaluated the volume of silt/sediment in the collected water samples. The results were rather scary, coz we discovered that each single liter of water contained more than two hundred and 50 ml of sediment. Previous tests during high flood levels in the early stages measured more than half silt. 

 I am not aware of any person who measured the silt levels at the lower ends of the estuary before this water flowed into the higher ends (northern sections)  of the lake as was mentioned to / the architects of the 2017 GEF PROJECT.  the IWPA can not say that they did not know of the very serious potential threat, which became a reality that we are now living with. this silt is in place and causing problems.

 The scientific team that drove the 2017 GEF PROJECT were warned of the rather substantial sediment loads of the Umfolozi River flood waters, but chose to ignore this coz it suited their crooked agenda. This scientific team needs to be held accountable for their arrogance and deliberate exclusion of the silt issue. The silt from the Umfolozi River flood waters now needs to be mechanically removed.

 This is not going to be cheap. The longer we wait, the harder this silt will become, as bentonite does its job of binding the silt and turning it to clay. There is evidence of this action at the current mouth to the St. Lucia estuary. The clay n the estuary mouth zone is rather problematic and restricts the water flow paths which should contain sand flats, but is currently mudflats. We need some serious government intervention. 

What to do ? 

How to organize things ?

 Please leave suggestions in the comments. Frankie2Socks for the 4u2fish campaign.