Big Trees, Steep Blocks: How to Clear a Blocked Stormwater Drain on Sydney’s North Shore

17 Oct Big Trees, Steep Blocks: How to Clear a Blocked Stormwater Drain on Sydney’s North Shore

It usually happens on a Saturday. Rain’s been hammering down since lunch, and you notice the downpipe near the laundry isn’t coping. Water’s leaking out of the joint halfway down, there’s a puddle spreading across the pavers, and when you finally lift the grate on the pit by the driveway it’s packed solid. Leaves, black sludge, a fair bit of dirt. Maybe a tennis ball. (There’s always a tennis ball.) If your place has big trees and a decent slope, none of this is a surprise. Every storm carries leaf litter and topsoil downhill, and it all ends up in the same couple of pits and bends. Leave it long enough and the soft stuff sets like clay, while roots quietly find their way into the old joints.

Here’s the thing most people get wrong. They hose the grate they can see, the water level drops, job done. Then two weeks later, after the next big downpour, they find the storm water drainage blocked all over again and have no idea why. Truth is, a blocked stormwater drain is hardly ever one clog in one spot. More often it’s a few smaller problems strung along the line, and clearing just one of them doesn’t buy you much. There’s an order that actually works, though. And there’s a point where the hose and the drain rods should go back in the shed, because past it you’re not fixing anything, just delaying it.

Work Downhill: How to Clear a Blocked Stormwater Drain the Right Way Round

Start at the roof, not the pit. Scoop out the gutters first (jacaranda flowers and gum leaves turn into a wet paste that’s surprisingly good at plugging a downpipe), then check the bend at the bottom of each downpipe. After that, grab the garden hose and run it into one downpipe at a time. The ones that drain fine, forget about. The one that backs up is your problem child. Write down which one it is, because once the rain stops you’ll forget. I know it feels like a slow way to unblock stormwater drain lines, but ten minutes of testing beats spending the afternoon rodding a pipe that was never blocked.

Next, the pits. Pull the grate off, put some gloves on and get the sludge out by hand or with an old trowel. It’s grim but it works. With the pit empty you can feed the hose, or a set of drain rods, down the outlet pipe and work at whatever’s soft. Gently, though. A lot of older homes still have terracotta stormwater pipes, and they don’t love being bashed. Then walk the line to wherever it exits. Could be a kerb outlet, could be an old rubble pit, could be an easement running through the neighbour’s place downhill. If that end is choked, nothing you did upstream matters much.

Two things not to do. Don’t bother with chemical drain cleaner. It won’t shift leaves or roots, and stormwater isn’t treated, so it all ends up in the creek at the bottom of the hill. And don’t ever run an overflowing downpipe into the overflow relief gully outside the laundry, no matter how bad the rain gets. It’s tempting when the water’s lapping at the back step, I get it. That gully is part of the sewer. Hooking stormwater into it is illegal, and in a heavy storm it can send sewage back up into your yard instead.

How do you know it’s more than leaves? Usually the drain tells you. The same blocked stormwater drain comes back within a month. Your rods come out with fine, hairy roots wrapped around the end. A strip of lawn over the pipe starts sinking. Any of those means the pipe itself is cracked or the joints have opened up, and no amount of effort to unblock stormwater drain pipes from the surface will fix that. Removing the tree isn’t a simple way out either, because plenty of councils won’t approve taking out a healthy tree over roots in a pipe that could be relined. A camera inspection is the sensible next step.

Stop Clearing the Same Drain Every Storm

If you keep finding your storm water drainage blocked after every decent rain, the pipe needs fixing, not another clean-out. Revolution Pipe Relining has relined over 31,000 metres of pipe, offers a lifetime guarantee on every relined section and sends someone back each year to check it on camera, free. Our no-dig pipe relining is done through existing access points, so the garden and the trees stay put. Most jobs are finished in a day.

Still weighing up how to clear a blocked stormwater drain on the North Shore, or wondering if yours is past the DIY stage? Have a chat with people who see this every week. Call Revolution Pipe Relining on 1300 844 353 for a free estimate or a no-obligation quote, ideally before the next storm.