We’ve seen a lot of water go where it shouldn’t on the Central Coast. Between the summer downpours, older housing stock in suburbs like Bateau Bay, Gosford, Wyong, and Umina Beach, and the sheer number of ageing flexi hoses hiding under sinks across the region, flooding isn’t just bad luck. Most of the time, it’s completely preventable.
Here are the top three causes of internal flooding we deal with regularly, and what you can do about them before they cost you thousands.
#1. The Silent Killer: Burst Flexi Hoses
If there’s one thing that keeps Central Coast plumbers busy, it’s flexi hoses.
These braided stainless-steel hoses connect your taps and toilets to the water supply, and they’re in almost every home. The problem? They go without warning. One minute, everything’s fine. The next, you’ve got centimetres of water across your kitchen or bathroom floor.
We had a unit this month alone flood from a burst flexi hose. And here’s what made it worse: there were no isolation valves under the sink. So when the hose let go, there was no way to stop the water locally; the residents had to find the main shut-off while water poured freely.
What you should check:
- Mini isolation valves: these should be fitted on every fixture. They allow you to turn off water to a single tap or toilet without killing the supply to the whole house.
- PEX-core flexi hoses: if you’ve still got the old cheap braided hoses, get them replaced. PEX-core hoses are significantly more reliable and are now the standard. They’re not burst-proof, but the difference in durability is substantial.
- Age matters: flexi hoses have a lifespan of roughly 10 years. If yours are older, have a plumber check them. It’s a $100 inspection vs. a $10,000+ flood damage bill.
If your home was built or last renovated more than 10 years ago, there’s a good chance your flexi hoses are overdue for replacement.
#2. The Blockage You’d Never Think to Look For
This one’s deceptively simple, and it caused thousands of dollars of damage during the last big rain event in Gosford, Central Coast.
A stormwater outlet at the curb had grass grow over it. That’s it. Over time, the grass trapped sand, leaves, and debris until the outlet was completely blocked. When heavy rain hit, the water had nowhere to drain, so it backed up onto the property and into the home.
The kind of flooding you’d expect from a major storm. Caused by overgrown grass over a drain.
What to do:
Walk the perimeter of your property, especially if you’re in lower-lying areas around Umina, Ettalong, Toukley, or near waterways on the coastline, and look for any stormwater outlets or grates at the curb or on your property boundary.
- Clear away any grass, leaf buildup, or sediment around them.
- Check after every major storm that they’re running freely.
- For underground drains, consider a CCTV drain inspection every few years to check for root intrusion or internal buildup.
It takes five minutes to check a stormwater outlet. A blocked one left undetected can cause damage you won’t see coming until it’s far too late.
#3. Hot Water System Flooding: A Ticking Clock in Your Cupboard
Hot water systems installed inside a cupboard, common in units and townhouses right across the Central Coast NSW, can become a serious flooding risk if they’re not set up correctly.
We attended a unit recently in Warnervale where the hot water tank had split. When a tank splits, it doesn’t drip, it dumps water continuously until someone physically shuts it off. There was no drainage tray, no flood stop valve. The water just kept flowing and flooded the entire unit.
Two things could have prevented it entirely:
- A safe tray with drainage: any hot water system installed indoors should sit in a tray connected to a drain. This isn’t just good practice; it’s a compliance requirement under current regulations. If the tank fails, water goes down the drain, not across your floor. If your indoor hot water system doesn’t have a properly connected safe tray, it’s worth getting a licensed plumber like us here at Thoroughgood Plumbing to bring it up to standard.
- A flood stop valve: a small, battery-operated device with a water sensor. If it detects moisture, it automatically shuts off the water supply. Simple, inexpensive, and can save tens of thousands in damage.
Bonus tip that applies to every household:
Do you know where your water shut-off valve is? Most people don’t, and that’s what turns a manageable issue into a disaster. Find it now (usually at the water meter near your front boundary) and make sure everyone in your home knows where it is.
The Central Coast Takeaway
These aren’t rare or exotic plumbing failures. They’re the three most common causes of internal flooding we see across suburbs from Gosford to The Entrance, Terrigal to Wyong, and in most cases, they’re completely preventable with a simple inspection and a few inexpensive upgrades.
If you’d like a plumber to check your flexi hoses, stormwater drainage, or hot water system setup, Thoroughgood Plumbing services the entire Central Coast. We’re locals, we know the conditions here, the housing stock, and exactly what to look for.
Call Thoroughgood Plumbing — Central Coast’s Trusted Local Plumbers
Third-generation, local, and ready when you need us. From burst flexi hoses to blocked stormwater drains and failing hot water systems, we know exactly what to look for.
Current Offer
Hot Water Health Check Inspection
Concerned about your hot water system? Thoroughgood Plumbing is offering a Hot Water Health Check Inspection — a great way to make sure your system is safe, compliant, and not a flood risk waiting to happen.
How long do flexi hoses last?
Flexi hoses have a lifespan of roughly 10 years. If your home was built or renovated more than a decade ago, it's worth having a licensed plumber inspect them before one fails.
Why is my stormwater drain backing up in heavy rain?
The most common cause is a blocked outlet — grass, leaves and sediment build up over the grate until water can't drain. Clearing it takes minutes; left undetected it can flood your property.
Does my indoor hot water system need a safe tray?
Yes. Any hot water system installed indoors should sit in a safe tray connected to a drain — it's a compliance requirement. If the tank fails, water goes to the drain instead of across your floor.
