PRESSURE MANAGEMENT
A vital part of any water-loss strategy:
PRESSURE MANAGEMENT
As a water services authority, the City of Cape Town (CoCT) is expected to implement water conservation and water demand management interventions to deliver water as efficiently as possible. Pressure management is an integral part of this commitment. By Kirsten Kelly
W
e immediately see the benefits of pressure management by reduced pipe bursts, which limits operational costs for repairs and, most importantly, limits water leaks. We also extend the infrastructure lifespan, postponing costly upgrades,” explains Ivy Maisela, senior professional officer, Water Demand Management Division, CoCT. She adds that through Cape Town’s drought period, 70 Mℓ/day of water was saved by pressure management alone. As water restrictions eased and water pressure increased, the savings have reduced to 20 Mℓ/day. As an ISO 9001 certified organisation, CoCT follows a process-based approach with regard to pressure management, where there is an increased focus on standard operating procedures and documenting all water pressure management activities. “Recordkeeping and documentation play a key role in water demand management.
Data integrity is very important,” states Maisela. A 10-year plan has been formulated on how CoCT will implement its pressure management strategy, prioritise areas in need of pressure management, analyse pipe burst statistics, evaluate different pipe materials, and look into average system pressures. Pipe distribution network A pipe distribution network can fail due to: • ageing infrastructure • f ailure of the joints of the pipeline (corrosion or age) • p oor workmanship (poor flushing/air in pipes) • high network distribution pressure (faulty valves). CoCT therefore focuses on reducing the pressure of its pipelines to
acceptable parameters. “Ironically, our pipelines often fail as a result of routine maintenance and daily operations. For example, when a burst pipe has been repaired, and there are air pockets in the mains, there are often additional burst pipes. Pressure management plays a vital part in pipe replacement programmes,” adds Maisela. Zone management CoCT’s water distribution network is divided into four regions that are further divided into pressure management zones. Zone management for non-complex areas is managed internally by CoCT, while complex areas are outsourced. Implementing zone management J UL / A U G 2022
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