Raw Water |
Potable Water |
Sewage |
Effluent |
Sludge Handling |
|
Raw Water in Rivers and Dams
Electricity to Pump
|
Water Treatment Plant
Electricity for Mixing Aerating Sterilizing & Pumping
|
Municipal Potable Water
Electricity to keep Reservoirs full and Boost Pressure
|
Municipal Waste Collection |
|
Electricity for Mixing Aerating Sterilizing & Pumping |
Municipal Waste Discharge into Rivers
Electricity to Pump
|
Municipal Sludge Disposal
Electricity for Drying Digestion & Health
|
Return Flows to Rivers
Water-energy nexus in the urban landscape
Adapted from SALGA Energy Guidelines
Now that we have mapped out the dynamics that have created water supply disruptions , let us home in on the process to inform readers about the risk they are increasingly facing . The biggest risk is the loss of resilience . Water supply is no longer stable , simply because inadequate planning means that internal storage capacity , needed to act as a buffer , is no longer there . Original urban design allowed for at least a 48-hour buffer period to cater for short-term shocks like pump failure . Nowhere is there a buffer capacity of any sufficient magnitude , and pumps have been poorly maintained , so they routinely fail . This means that a series of load shedding events prevents reservoirs from filling . If any additional shock occurs , such as a pump failure , the whole system crashes . This is now unavoidable . It cannot be fixed in the short to medium term , as it requires major engineering intervention in the absence of coherent planning .
The second biggest risk is associated with contaminated rivers , because none of the potable water plants were ever designed to convert sewage into safe drinking water . Water quality is deteriorating , and this , too , is not easily fixed in the absence of coherent planning .
An important risk that needs to be dealt with is the fire risk associated with the lack of water availability to first responders . If a fire breaks out during a load shedding event , which is also associated with a loss of water pressure , the fire hydrants will be useless . Careful thought must be given to this matter as it has implications for the loss of life and property .
From an estate management perspective , this has a profound impact . Stated simply , it means that as municipal service delivery fails , managing agents and bodies corporate will increasingly become the new service providers . As a general principle , it can be accepted that in the next six months , there is a 70 % probability that most estates will face at least a 48-hour disruption , depending on where they are located . Few trustees want to take on this responsibility , but as the overall system fails at municipal level , this is what will inevitably have to be done . Some estates have already implemented uninterrupted water supply systems and are now able to provide stable services to their constituencies , irrespective of the disruption caused by municipal failure .
Dr Anthony Turton
41 S U S T A I N A B I L I T Y