Water Outages in Centurion: What a Home Backup System Needs to Cover

Centurion sits at the end of a long supply chain. Rand Water treats bulk water at its Vaal-sourced plants, pushes it to Tshwane’s reservoirs, and from there it travels through ageing reticulation to your tap. Any planned maintenance, burst main, pump failure or load-shedding event at any point in that chain can leave your suburb dry — sometimes for hours, sometimes for two or three days. Understanding what a backup system must actually do is the first step to sizing one that works.

Why Centurion Outages Happen

Tshwane Municipality publishes planned shutdowns on its website, and Rand Water logs its own supply interruptions separately. The two systems interact: Rand Water can restrict bulk supply during infrastructure work or drought-response measures, and Tshwane’s own reticulation network — much of it laid decades ago — generates its own burst-pipe emergencies independent of anything Rand Water does. For a plain-language explanation of where bulk interruptions start, the article on Rand Water shutdowns explained is worth reading before you size a tank.

The practical result for Centurion homeowners is that outages are rarely predictable and rarely short. Planning for a single overnight gap is under-engineering the problem.

How Much Water Does a Household Actually Need?

South Africans use on average about 237 litres per person per day — above the world average of roughly 173 litres (IWA Water Policy figures). A family of four therefore uses something in the region of 950 litres per day under normal habits. Backup storage is not about replicating normal habits, though; it is about covering essential use — drinking, cooking, toilet flushing and basic hygiene — which typically drops to 50–80 litres per person per day when people are consciously conserving.

As a rough guide:

• Family of two: 100–160 litres per day essential use
• Family of four: 200–320 litres per day essential use
• Family of six: 300–480 litres per day essential use

For two to three days of cover at essential-use rates, a 2,500 litre tank covers a family of four comfortably. Many installers recommend 5,000 litres as the starting point if your suburb has a history of multi-day outages, or if you run a home business that cannot afford any interruption.

Automatic Switchover: The Feature Most People Overlook

A tank sitting in the garden does nothing on its own. The moment municipal supply drops, you need the system to switch your house over to tank water without you opening valves manually at 2 am. That requires a dedicated switchover arrangement — either a float-valve-based gravity feed for low-pressure use, or more commonly an automatic pressure switch that starts the pump the moment line pressure falls below a set threshold.

The guide to municipal-to-tank switchover covers the plumbing logic in detail, but the short version is: automatic switchover keeps the rest of your plumbing working normally and prevents the pump from running dry if the tank empties.

Pump Power and Load Shedding

Centurion’s water outages and load shedding often coincide — Tshwane’s pump stations lose power during load shedding, which is one of the reasons taps run dry even when there is technically water in the network. If your backup pump runs from the grid and the grid is off, your tank becomes a very expensive ornament.

The practical fix is a small inverter with a battery bank sized to run the pump for the duration of typical outages. Most domestic pressure pumps draw 0.5–1.5 kW; a modest inverter and two to four 200 Ah batteries can run a pump intermittently for 24 hours or more. Alternatively, if you already have a solar-plus-battery system, your installer can wire the pump onto the backed-up circuit. The backup water pumps and inverters article explains the wiring options and what questions to ask an installer about battery sizing.

If you want to know what a properly sized system costs for your specific property, it pays to get more than one opinion. Compare 3 free quotes — vetted installers, no obligation.

Sizing the Tank: Practical Rules of Thumb

Tank size interacts with roof area if you plan to harvest rainwater as a top-up source, and with available ground space. For pure municipal-backup use, the sizing is simpler:

Household size	Essential daily use (rough guide)	Recommended minimum tank	Days of cover
2 people	100–160 litres	2,500 litres	~15–25 days
4 people	200–320 litres	2,500 litres	~8–12 days
6 people	300–480 litres	5,000 litres	~10–16 days
6 people + garden	500–700 litres	10,000 litres	~14–20 days

These figures assume essential-use discipline during an outage. Add roughly 30–50% capacity if your household is unlikely to conserve, or if you have a pool or irrigation system drawing from the same supply.

The full guide to backup water systems covers tank materials, placement requirements and how rainwater harvesting can be integrated into the same setup.

What a Complete System Typically Costs

As a Johannesburg reference point (use these only as a directional guide for Centurion — confirm via quotes), backup tank-and-pump systems typically run R20,000–R40,000 for a straightforward single-tank installation, with whole-house setups closer to R55,000. Pump hardware alone typically costs R15,000–R35,000 installed. Actual quotes for your property will vary based on tank size, reticulation complexity, whether the pump needs its own electrical circuit, and whether an inverter is included.

Get at least three quotes before committing. Installers price very differently depending on their supply relationships and what they include in the scope.

Prices vary more than most homeowners expect — the only reliable number is one from an installer who has seen your property. Request quotes from three vetted installers — free and without obligation.

What to Ask Before You Sign Anything

A good installer will visit the property before quoting, not quote over the phone. Ask specifically:

• What is included in the switchover? Automatic pressure-switch systems are standard; manual valve arrangements are cheaper but impractical.
• Is the pump wired to a backed-up circuit? If not, you will have water in the tank and no way to pressurise the house during load shedding.
• What happens when the tank runs out? The system should fail gracefully back to municipal supply the moment pressure returns, without you doing anything.
• What is the warranty on the pump and tank separately? These components have different lifespans and failure modes.

For Centurion specifically, check the installer’s familiarity with Tshwane’s reticulation pressure ranges — Centurion’s supply pressure varies by suburb, and a pump set up for one pressure profile may short-cycle or underperform in another. That is not a detail a remote quote will capture.