The place where the water from the Mooi River enters the Mpofana is known as the Outfall Point. During our 21 kilometre walk down the Mpofana we realised that there is a clear difference in the types of impact and the condition and health of the Mpofana upstream and downstream of the outfall point. Thirteen kilometres from its source, having meandered for +-2,5 kilometres across a floodplain, the Mpofana reaches the outfall which is situated at a right angle to the water course and is a mere 600 metres upstream of the end of the floodplain.
The banks on the floodplain upstream of the Outfall seem fairly average with vegetative cover and no signs of excess erosion.
Immediately opposite and downstream of the outfall however, the banks are clearly eroded
and it is evident that the river is eroding and changing course as the waters erode a straighter channel.
Some of the meanders are such tight switch backs that it seems highly possible that they will disappear.
Farther downstream of the outfall point we saw constant evidence of erosion that we had not seen upstream of the outfall: predominantly collapsed river banks with fences suspended over thin air and water.
Silt consistently smothering the river bed and submerged rocks.
This was particularly noticeable as upstream of the outfall point, the river bed and submerged rocks were visible for most of the +-13km. Of four test sites upstream of the outfall site there was no silt visible at three sites and only a light concentration at the fourth.
However downstream of the outfall point, there was a slightly elevated silt level at one site, and high levels at three sites.
There is no doubt in our minds that the erosion of the Mpofana banks has been accelerated by the waters of the transfer scheme.
As mentioned earlier, at the inception of Phase 1 of the scheme, attempts were made to monitor the impacts of the transferred water. This was done by placing metal stakes on the edge of the river bank. Unfortunately it seems as though most of these stakes have fallen into the river as the banks have eroded and collapsed – we only saw one stake along the river. Being unpainted, they are also difficult to spot.
A week after our walk, consultants surveyed the Mpofana in order to provide a benchmark of current conditions. This will be followed by a five year monitoring program and at the end of the five year monitoring period a decision will be made on how to manage / mitigate / rehabilitate any impacts from the increased loads of water in the Mpofana. In the meantime no doubt the rivers health will continue to be negatively impacted by the increased loads of silt.
Unfortunately the only section to be surveyed as part of Phase 2 is the Mpofana from outfall to Lions confluence. Thus no comparison will be made between the sections of the river upstream and downstream of the outfall which gives an indication of impacts already occurring as a result of the transfers. Nor will the Lions River be surveyed downstream of the confluence with the Mpofana, which would not only have given an indication of the impacts thus far, but would also have provided an indication of what future impacts from the increased transfer will be.No cognisance seems to have been taken of the fact that the Mpofana is already heavily impacted after almost 30 years of unnaturally high water levels and by implication, there is no concern about the impacts. One thing is for certain: the damage has already begun, and when the new increased transfers begin, the impacts will continue and may be exacerbated.
The Mpofana river pays the price for water supply to continually growing greater eThekwini. Would it not make more sense to invest in PROTECTING the ecological infrastructure on which we all rely?