Work out why your water pressure dropped before you call anyone
If your shower went weak overnight, this walks you through the quick checks that tell a City dip from a problem in your own pipes. Written for Fish Hoek and Kalk Bay homes.
By Zaid Petersen, Owner and master plumber
Yes, water pressure can come back on its own, because in Cape Town it is often managed rather than fixed at one level all day. The City eases pressure on older mains at busy times, like early evening, then lifts it again once demand drops. If your pressure sagged and returned within a few hours without you touching anything, that pattern points to the supply being managed, not a fault in your own pipes. A drop that stays weak at every hour, in every tap, is a different story and worth a closer look.
What low pressure actually means in a Cape Town home
Water pressure is the force that pushes water through your taps. In Cape Town it is measured and managed, not left to chance. The City sets a target for how hard the water should arrive at your boundary. In older far-south areas, they often turn it down on purpose to stop old mains from bursting.
So a weak shower is not always a fault. It can be the pressure the City chose to send you that morning. Many homes in Kalk Bay and Fish Hoek sit on mains laid decades ago. The City eases the load on them during the day.
That managed figure is the part most people never hear about. Knowing it exists changes the first question you ask when the pressure drops. And the first thing to work out is where that pressure stops being the City's problem and starts being yours.
Is it the City's supply or your own pipes
So how do you tell the two apart? Ask whether it is one tap or the whole house and whether it happens at a set time of day. A City dip hits everything at once. One weak tap, with the rest running fine, points back at your own pipes or a blocked fitting.
Time of day is the other giveaway. The City often reduces pressure in the early evening, when the whole street is cooking and showering at once. If your pressure sags around 6pm and comes right later, that pattern is the supply, not your plumbing.
A private fault behaves differently. It does not care what time it is. A blocked aerator on the kitchen tap is weak at 6am and weak at midnight. Meanwhile the bathroom down the passage runs normally. Watch which taps are affected and when. The cause starts to name itself.
Steps to check before you call a plumber
- Open the same cold tap you noticed first. Watch the flow for a few seconds and note whether it is a trickle or just softer than usual.
- Try two or three other taps around the house, including one upstairs if you have a second storey. See if the weak flow is one tap or all of them.
- Ask a neighbour or two whether their pressure is low as well. If the whole street is down, the cause is outside your boundary.
- Check the time. Check again a few hours later. A dip that clears by mid-morning is usually the City managing the mains.
- Unscrew the aerator, the little mesh cap on the tip of the weak tap and rinse out the grit. Screw it back and run the tap again.
- Look at your water meter with every tap closed. If the dial is still turning, water is moving somewhere it should not be.
When low pressure points to something bigger than a blocked aerator
So water is moving. Let's find out where. If the whole house stays weak at every hour and your neighbours are fine, the problem is almost certainly inside your own pipework. A cleared aerator and a steady meter rule out the easy causes. What is left tends to be the pipes themselves.
In pre-1980 far-south homes, that usually means old galvanised line. These pipes rust closed from the inside over the years. They narrow until barely a trickle gets through. You cannot clean that out. Once the bore has scaled up, the fix is new pipe. That is the work covered under pipe replacement (repiping).
A turning meter with every tap shut is the other serious sign. The reading means water is escaping between the meter and your taps. Often it is a buried pinhole leak, losing pressure before it ever reaches you. On a weekday you can send a photo of the exposed pipe or the meter. You will get a ballpark back within the hour, so you know whether this is worth a closer look.
Most low pressure is a City dip you can wait out, or a fitting you can clear yourself. When it is the whole house at every hour, with a meter that will not sit still, that is the one worth a second pair of eyes before it gets worse. For wider background, see Interruptions to water supply (Water UK).
Frequently asked questions
Will a plumber actually turn up when they say they will, or will you be left waiting?
You can ask for a time window when you book and expect a call if that changes. A plumber who respects your day will tell you straight away if something runs late, instead of leaving you watching the gate.
Will the plumber rush through your job because they've got another one booked after yours?
A proper check of your pressure takes a few minutes of running taps and checking the meter, not a five minute dash. If someone is in and out before you've even shown them the weak tap, that's worth noticing.
Will you be charged a fortune just to sort out something small, like an aerator?
What drives the cost on a small job is mostly the time on site and what you can ask us to walk through before we start. The real way to know is to ask for a straight answer before anyone starts, so you're not guessing.
What if you pay for a visit and the pressure problem still isn't fixed afterwards?
That usually means the first visit treated the wrong thing, like clearing an aerator when the real cause was deeper in the pipe. If the same tap is still weak afterwards, say so and ask what else was checked, because the fix should match what was actually found, not just the easiest guess.
If a burst pipe caused the low pressure, will you get the paperwork your insurer needs?
A burst is a different problem from a slow pressure drop and it usually needs its own report rather than a quick chat on site. Ask upfront whether you'll get something in writing describing what failed, since insurers want that on paper, not just a verbal explanation.
What happens if you phone about low pressure and nobody calls you back?
If a call goes unanswered, try again later in the day rather than assuming the worst straight off, since low pressure on its own is rarely an emergency that can't wait a few hours. If it still goes quiet after that, it's fair to look elsewhere, no one should leave you hanging on something this ordinary.
Ready when you are
If you would like to take this further, Pipe replacement (repiping) is the place to start.