In South Africa, as in the rest of the world, agriculture is the largest user of freshwater resources, surface and groundwater included. For South Africa, agricultural use amounts to about 60% of the total use. Irrigated agriculture is therefore increasingly under pressure to produce more food with less, or the same amount of, water.
This goal can only be achieved if advances in irrigation technology and research on crop water needs are applied appropriately in irrigation systems. The accurate monitoring and measuring of water use are integral to this process.
As a commercial irrigator you have different roles when it comes to water management. On-farm, you run a business enterprise, which means that you manage water to improve irrigation efficiency and water productivity. In the same role, you also manage water as a critical resource whose availability and quality are major risks.
On-scheme, you have a different role. Here you are a member of a local water resource management institution, and as such you have a co-responsibility to minimise water losses resulting from infrastructure, bad management practices and unauthorised withdrawals.
In all these roles, you are accountable to government and the Department as the custodian of water in South Africa.
In terms of Government Notice 131 (2017), the Department may direct any water user, where it has reasonable grounds to believe that the water user is not complying with the provisions of regulation 5 (Installation and use of water measuring devices and record keeping), to comply with the regulation at the water user’s expense, and provide proof of such compliance to the Department within one month of the date of receipt of the directive.
Government Notice 141 (2018) instructed Irrigation Boards and Water User Associations to install water measuring devices. The Notice stipulates that Irrigation Boards and Water User Associations must instruct their members to install water measuring devices in line with Government Notice 131 of 2017.
Government Notice 34 (2020) extends the requirement to install water measuring devices to irrigators who are not members of Water User Associations or Irrigation Boards.
Yes, if you have received a directive from the Department or the local water resource management institution. Government Notice 131 (2017) states that the directive to measure “apply to all taking of water from a water resource for the purpose of irrigation where the water user is required to measure such water”.
According to the Department’s guidelines for measurement (page 8 and 9), water users are required to measure:
- water abstracted from the water resource, and
- return flows.
Return flows are usually small streams occurring at different places and are not easy to measure. The Department regards them as part of the water loss of a scheme.
In schemes where it is possible to measure return flows, it is advised as it will give a more accurate water balance of the scheme.
The Department prescribes functionality, but not a type of meter or a brand. For the details of the functionality that the Department requires see the Guidelines for measurement.
It is important that you understand the advantages and disadvantages of each type of meter for your specific conditions and budget.
Also, make sure that you select a meter that meets the functionality requirements of the Department. You will find this here.
We recommend that you also talk to users in your area or other areas who have experience of meters, and your local suppliers of water meters.
For open channel flow metering, you can expect an error of approximately 8%.
For the different types of meters, you can expect the following accuracies:
- Mechanical meters are usually the least accurate. With the latest technology, they can have an accuracy of 2%.
- Electromagnetic meters have an accuracy between 0.5% and 2%.
- Ultrasonic transit time meters have an accuracy between 0.5% and 1%.
The water user must pay for the device. A local water resource management institution may decide to buy water meters in bulk to negotiate a better price for their members.
According to Government Notice 131 (2017), the water user must operate and maintain the water measuring device in accordance with the requirements and specifications of the supplier and the Department. The water user must keep a record of such operation and maintenance.
Irrigation Boards and Water User Associations must monitor if their members comply with the measuring requirements contained in Government Notice 131 of 2017.
They must report to the Department on the compliance of their members and they must take measures against those who do not comply in terms of Sections 53 and 54 of the National Water Act of 1998 (Act 36 of 1998).
(According to the Department)
According to Notice 141 (2018) and Notice 34 (2020), water users are required to submit their water measuring records on a monthly basis directly, or through their Water
Users Association or Irrigation Board, to one of the following emails depending on their location: