Sinokubonga Nkala
As the climate change effects continue to manifest on our rangelands, one thing certain is that livestock farmers need to have an answer in terms of how to mitigate against these effects.
We are halfway through December and rivers are yet to flow and dams have not registered any meaningful inflows.
One aspect of climate change mitigation which livestock farmers and all stakeholders need to embrace as a matter of urgency is the issue of water harvesting. It is absurd that we watch rivers, small and big alike draining copious volumes of water when they are in flood, yet a few days down, we scream of unavailability of water.
Harvesting of both surface and ground water needs to be improved if water provision for livestock and other uses can be continued.
There has been significant improvement in terms of taping underground water, with the earth being punctured for boreholes across rural and urban communities. My major concern, however, is on surface water harnessing, which requires dams and weirs to be either constructed or rehabilitated.
It is the rehabilitation part which I feel needs to be upscaled, especially desilting of major water bodies. Civil engineers will tell you that it is cheaper to construct a new dam than to desilt an existing one, however, in most communities we have simply runout of sites for new dams due to human settlement and other geological factors.
It is my conviction that a dam which has been desilted even one third of the silt will improve its water holding capacity significantly.
I am no civil engineer and therefore am certainly off base with regards to the technical aspects of desilting but I strongly feel that it is an option which we still need to keep on the table and try to find easier and cheaper ways of doing it.
With technological advancement, I will be not surprised to learn that there now exist a more efficient and even affordable equipment to do this task.
Most of our dams, big and small, have lapsed lifespan and are now heavily silted due to a myriad of factors which include poor agricultural approaches upstream.
This includes wanton stream bank cultivation and crop fields with no contour ridges which allows for washing away of the top soil down stream all the way to the local dam.
I know of some big dams which used to supply big irrigation schemes throughout the year but they now cannot go past September regardless of how good the rainfall season was.
The capacity of the dam has been reduced by more than fifty percent over the year due to siltation. This year’s drought actually presented a good opportunity for the community and government to desilt most of the dams, as they completely dried out.
It is my submission therefore that the Government and community need to face this problem of silted head on and keep desilting as a option on the table if we are to improve water availability for our communities.
Let us explore new technologies regarding rehabilitating silted waterbodies and see which one can work for our communities.
We also need to have extensive watershed management approaches which promotes infiltration as opposed to run, especially in cropping fields and rangelands.
This will ensure recharge of the underground water and improve water tables which as of now are getting deeper every year.
An improvement on the water table will reduce the depth one needs to drill to get water from the borehole.
Therefore, the water harvesting needs a holistic approach which tackles the challenge from a number of angles.
The import of this submission therefore, is that we need to respond to the climatic changes by putting measures that ensure that communities continue to get enough water for both domestic and agricultural use, or else we may witness the decline and eventual death of agricultural sectors such as livestock production as it becomes untenable and impossible to keep animals on a veld with no drinking water.
I may not have the best answers but at least I am pointing right at the problem we need to solve for the posterity of humanity. Uyabonga umntakaMaKhumalo.
Mhlupheki Dube is a livestock specialist and farmer. He writes in his own capacity. Feedback [email protected] cell 0772851275
