Mailbox: Water wastage in agriculture a serious problem

BizNews reader Thys Kapp has written to Portia Chawane, Environmental Officer at the Department of Water and Sanitation and James Mofokeng, Environmental Specialist at the Department of Water and Sanitation on two separate occasions to highlight his concerns around water wastage in agriculture. Kapp points to issues around the Vaal dam in particular, where he notes that his neighbours pump the equivalent of what a small town would consume. He suggests that the Department of Water and Sanitation improve metering systems in order to clamp down on water waste on farms, particularly in winter, which depletes the dam to critically low levels. The department has yet to respond to Kapp’s letters.

By Thys Kapp

Our concern is water conservation.

Every time I see notices that people should be conserving water I can help but cringe because while we are all trying to save cents the largest water wastage is happening in agriculture, and the farmers attitude is that if you can afford the diesel then it’s your right to pump as much water as you want from the Vaal dam or any other dam if you prefer.

Can we keep blaming evaporation for the huge level drops in the Vaal dam? Yes but only if you qualify it by explaining that the water is evaporating from the fields that are being irrigated during midday.

Here is an extract from a very simple google search:

‘This example shows the minimum water supply rate for a centre pivot equipped with high-pressure impact sprinklers should be approximately 772 gallons per minute (656/0.85). The minimum system flow rate for a centre pivot with low-pressure spray nozzles at truss rod height would be 690 GPM (656/0.95)’

690 gallons per minute is 2600 litres per minute therefore 156,000 litres per hour and in 24 hours it could use 3.75 million litres. (I have seen that these pivots run 24 hours a day 9 months of the year) . Before we get technical about the length of the pivot and the pressure, there is no doubt that a spindle/pivot irrigation system uses that same amount of our precious resource, water, as a small town.

I accept that internationally irrigation is a major consumer of water but there is currently no motivation to use water effectively if the authorities are not metering the consumption. Below is a screenshot of the South African fact sheet on AQUASTAT:

Water affairs have forgotten to look around the Vaal dam at how many illegal dwellings have been built below the 120% mark, how many sewer systems are going straight into the dam, how much illegal fishing with gill nets is taking place and how much of this resource is being wasted by irresponsible consumers.

If you want to manage this resource you have to meter it.

I sincerely hope you have taken the time to read my email this time around.

Kind regards,

M J M Kapp

Email dated 26 February 2021:

Good morning Ms. Chawane and Mr. Mofokeng,

I noted that there seems to be a company applying for water use licenses from the Wilge.

My immediate thought is that someone has seen an opportunity to pump from the Wilge and then to resell it to farmers? IF this is the case then I think that there is something drastically wrong with the system, it either means that the DWS metering is not working or poorly managed which in turn allows the resale of water to be profitable?

We are surrounded by farmers who pump water from the Vaal, during winter the pumps run non-stop, pumping the equivalent to what a small town will use. Unfortunately in my experience, conservation and farming are not compatible, whether its birds, animals or natural resources. I have also spent a lot of time reading about the subject and understand that it’s an international trend that agriculture uses the majority of this resource however, we need to do our part to reduce waste.

Above is an ideal situation to put ground rules/meters in place to ensure we don’t have the Vaal dam sitting at 50% by October again.

I apologise for high-jacking this platform but I feel very strongly about this subject.

Kind regards,

Thys Kapp

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