Blocked stormwater drain help on the Northern Beaches
Updated October 2026
Stormwater drains only get tested when it rains, and by then it is too late to find out they are blocked. Water pooling against the house, overflowing gutters and downpipes, a flooded garage or a swampy lawn are all signs the stormwater system is not carrying water away. Beaches Blocked Drains connects you with licensed local drain plumbers who clear and repair blocked stormwater drains across the Northern Beaches.
Signs of a blocked stormwater drain
- Downpipes overflowing at the top during rain
- Water pooling around the base of the house or in low spots of the yard
- Grated surface drains and channel drains holding water
- Damp patches, moss or rising damp on walls near ground level
- A soggy section of lawn that never quite dries out
Unlike a blocked sewer, a blocked stormwater drain rarely smells or backs up indoors, so it often goes unnoticed until a heavy downpour causes flooding or water damage.
Why stormwater drains block on the Northern Beaches
The Beaches works its stormwater systems hard, and a few local factors do most of the damage:
- Sand. In beachside streets from Manly and Freshwater to Collaroy, Newport and Palm Beach, sand blows and washes into pits and pipes and settles in the flat sections. Over time the pipe silts up until a moderate shower overwhelms it.
- Leaves and bark. Spotted gums and angophoras shed constantly across the Pittwater suburbs and the bushland edges of Belrose, Davidson and Allambie Heights. Leaf litter washes off roofs into downpipes and collects at bends and pits.
- Tree roots. The same roots that invade sewer lines invade stormwater pipes, especially older clay or concrete lines. Stormwater pipes are often shallower than sewers, which puts them closer to feeder roots.
- Steep blocks and run-off. On hillside streets in Fairlight, Bilgola, Whale Beach and Collaroy Plateau, water arrives fast and carries soil, gravel and garden mulch with it. Pits at the bottom of the slope take the load.
- Low ground. Around Narrabeen Lagoon, Manly Lagoon and the Warriewood valley, high groundwater and flat falls leave little margin when a line partly blocks.
What clearing a stormwater drain involves
The licensed drain plumbers we work with usually take this approach:
1. Inspect pits and downpipes. Many blockages sit in an accessible pit full of leaves and sand, which can be cleared by hand or vacuum.
2. Jet blast the lines. High-pressure water jetting flushes sand, silt and leaf litter through the pipe and cuts tree roots off the walls. For sand-laden lines in the coastal suburbs this is the standard method.
3. Camera the pipe. A CCTV inspection confirms the pipe is clear and shows any cracks, sags or collapsed sections that will keep catching debris.
4. Fix structural faults. Broken sections can be repaired, relined or re-laid, and poorly draining designs improved with extra pits or re-grading.
What it costs
Costs vary by job. A standard stormwater blockage clear on the Northern Beaches typically runs $150 to $400, around $280 for most jobs. Tree root clearing typically runs $250 to $600. A CCTV inspection typically runs $249 to $600, and a combined camera and jetting job typically runs $350 to $900. If roots have broken the pipe, relining typically costs $3,000 to $8,000 or more depending on the length of the damaged run.
Whose drain is it
Private stormwater drainage on your property, from roof gutters and downpipes to the street kerb or the council system, is the owner's responsibility. The pits and pipes in the street belong to Northern Beaches Council, and the sewer mains belong to Sydney Water. If water is backing up from a blocked street pit rather than your own line, report it to the council. A plumber can quickly tell you which side of the boundary the problem sits on.
Get ahead of the next storm
The cheapest time to fix a stormwater drain is a dry week. If your drains struggled in the last east coast low, a clear and camera inspection now costs far less than water damage later. Beaches Blocked Drains is a local referral service: we connect you with licensed drain plumbers who service Beaches suburbs from Seaforth and Frenchs Forest to Mona Vale, Avalon Beach and Palm Beach. Tell us what you noticed and get a fast quote.
Frequently asked questions
How much does it cost to clear a blocked stormwater drain on the Northern Beaches?
Typically $150 to $400 for a standard clear, with combined camera and jetting jobs typically $350 to $900. Sand-heavy or root-affected lines sit toward the upper end. Costs vary by job.
Why does my stormwater drain keep filling with sand?
In beachside suburbs, sand blows and washes into pits and settles in flat pipe runs. Jetting flushes it out, and fitting silt traps or fixing pipe grades slows the build-up.
Who is responsible for stormwater drains, me or the council?
You are responsible for the drainage on your property up to the kerb or the council connection. Northern Beaches Council looks after the street pits and pipes.
Can tree roots block a stormwater drain?
Yes, and on the Beaches they often do. Stormwater pipes are usually shallow, which puts them within easy reach of gum and fig roots. Jetting clears the roots, and a camera shows whether the pipe itself is damaged.