Load Management Projects at the Department
of Water Affairs through an Integrated
Systems Approach
Chris Scheepers
15 August 2012
The Need for Water...
 South Africa is divided into 19 water catchment areas.
 Water is transferred to different areas and national key important
instances.
Water needed for:
 Agriculture
 Municipalities
 Power stations
 Chemical processes
(Sasol)
 Mines
Usutu-Vaal
water scheme
Usutu-Vaal Government Water
Scheme (GWS)
Matla PS
Secunda
Standerton
Usutu-Vaal GWS Pump Station
and Clients
Pump Stations
Clients/Destinations
 Naauwpoort (Witbank);
 Duvha P/S (if needed)
 Rietfontein (Secunda);
 Matla P/S (Kriel P/S)
 Grootfontein (Charl Cilliers);  Sasol and Rietfontein dam
 Grootdraai and Tutuka
 Tutuka P/S and Grootfontein
(Standerton);
weir
 Geelhoudboom;
 Grootdraai- and Morgenstond
(Between Morgenstond- and
dam
Heyshope dam) and
 Heyshope (Piet Retief).
 Geelhoutboom pump station
Usutu-Vaal GWS Layout:
Grootdraai (GD) Dam Supply
 Grootdraai backup


supply:
• Heyshope- and
• Geelhoutboom
pump stations
Pump when GD is
below minimum
operating level (80%).
Usually during the
winter/dry seasons.
Usutu-Vaal GWS Layout: Client
Supply
Installed Capacity




Target savings
Tutuka (4x 1405 kW)
Grootdraai (4x 1650 kW)
Grootfontein (1x 2200 kW
3.80 MW
3.15 MW
and 4x 2150kW)
Rietfontein (4x 3050 kW)
3.20 MW
Usutu-Vaal GWS: Previous
Control Philosophy
 Relay logic control panels were used.
 Limited remote control.
 Limited condition monitoring available.
 Limited monitoring of dam/reservoir


levels.
Time of use (TOU) not taken into account.
No data trending was available.
Load Shift Project:
Usutu-Vaal GWS – Scope of Work
Upgrades on Grootdraai, Grootfontein and Rietfontein:
 Upgrade pumps to enable




automatic control.
Upgrade centralise SCADA &
include a REMS
Install additional
communication infrastructure.
Monitor dam levels – GSM
modems.
Control system to optimise
load shifting potential.
Usutu-Vaal GWS: New Control
Philosophy
 PLC panels allowed for remote control.
 Previous control philosophy was used.
 Pump station control updated – communication between



pumps.
Detailed conditioned monitoring.
Dam levels monitoring by GSM modems.
Integrated control philosophy between the pump stations.
Usutu-Vaal GWS: Introduced
SCADA
 New SCADA with condition monitoring.
Usutu-Vaal GWS: Integration of
pump stations
 Grootdraai (GD) pump into Vlakfontein Canal to Grootfontein:
• 24 hours with 1 GD pump
• 11-12` hours with 2 GD pumps
 Grootfontein pump water from forebay to Knoppiesfontein

towers.
Water may not be spilled at the Grootfontein weir.
41 km Vlakfontein canal
Usutu-Vaal GWS: Grootdraai
Pump Station Results
 Grootdraai pumps stopped at the following times:
• 07h00 to 09h00 – To ensure water ‘shortage’ at Grootfontein.
• 18h00 to 20h00 – Evening load shift.
 Note: Tutuka pumps only stopped during evening peak.
 Achieved load shift (3

months): 3.8 MW
103% performance.
(Load shift for
Grootdraai and Tutuka)
Usutu-Vaal GWS: Grootfontein
Pump Station Results
 The Grootfontein pumps were stopped:
• From 06h00 due to evening load shift at Grootdraai.
• 18h00 and 20h00 – Evening load shift.
 Achieved load shift (3

months): 3.2 MW
107% performance.
Usutu-Vaal GWS: Rietfontein
Pump Station Results
 The Rietfontein pumps were only stopped during:
• 18h00 and 20h00 – Evening load shift.
 Achieved load shift (3

months): 6.34 MW
198% performance.
Conclusion
 Large electrical loads were shifted out of the evening peak.







(Average 3 month total of 13.4 MW)
The supply to the clients was not compromised.
The control philosophy was revised and updated.
The control between pump stations was successfully integrated.
Advanced condition monitoring are done by the SCADA.
Control allows for most efficient pump combinations to be
operated.
Remote access is possible for maintenance, control and support.
Pumps were refurbished - not included in the initial contract.