Merweville Case Study the Great Karoo
Merweville is a small town in the heart of the Great Karoo. The area is well known for the Karoo Lamb farmed in the area, and the historical Dutch Reformed Church has featured in many a picture.
Like many parts of South Africa and especially the Karoo, the town has been badly affected by drought in recent years. The town has a population of less than 2000 inhabitants. Until very recently the town had to get by with an interrupted water supply. Water supply was switched on and off as part of the management program to give the reservoir chance to fill up. This left the consumers without water for many hours a day to give the reservoir’s level a chance to recover. It is almost unthinkable to imagine everyday life without water coming from an opened tap.
In 2021 some existing boreholes were equipped with pumps and control equipment to improve some of the existing infrastructure. Some of the boreholes were even equipped with solar power to assist with the frequent power outages that are experienced during load shedding. As part of a collaboration between local contractor, TG Elektries and Integ System Integration a modern Telemetry and Control system was installed. The software platform is hosted in a data center and viewed as a web page. This system enabled the client to have the SCADA available on any laptop, tablet or smartphone with an internet connection. This was a big mind shift from a traditional on-site SCADA. The benefit of the hosted SCADA has proved to be bigger than expected!
Telemetry Systems Make Managing Scarce Water Resources Effortless
The hosted SCADA removed the responsibility for SCADA PC hardware and provided a service where the client can look at the system’s data being run on up-to-date hardware and software thus ensuring long term reliability. Many rural municipalities have theft problems and by removing the SCADA from site, this problem has been eliminated. The SCADA hardware is regularly checked for software updates, and security is kept up to date to allow for secure and reliable operation.
Tabateq supplied the Elpro 415U-E-C4 as a communication solution to connect directly to the PLC via Modbus TCP/RTU. All the data from the various outstations was sent to the central site, from where it is sent to a hosted SCADA via the MQTT protocol. The MQTT protocol was selected due to the low data requirements of this protocol. It is ideal for slow (UHF) networks or networks where the data is being billed for, like LTE. The Elpro 415U-E-C4 operates as a traditional UHF radio for telemetry use, with the added benefit of giving the user cloud access if required. When data was sent to the hosted SCADA, the typical response for a change happening in the field to the data being seen on a cellphone/laptop was well within the accepted norm for telemetry systems in the water industry, even though the SCADA was not on site.
The person responsible for the Merweville water network is based in Beaufort West, more than 100km away. The ability to monitor the SCADA system in real-time is a big help to the client as he can now monitor the critical water network for Merweville from anywhere. They can now respond to low water levels, pipe leaks and pump trips much quicker than before. The same data can also be shared with other government departments that do water management from a provincial or national government level.
The interventions undertaken have improved the water availability to the consumers a lot, and the system is enabling the client to make data-driven decisions based on real-time data.