Every big east coast low reminds Illawarra homeowners that stormwater and sewer are two separate systems with two very different failure modes. Stormwater takes roof and surface water to the street, a kerb outlet or a legal point of discharge. When it blocks, you get water where you least want it: against the slab, under the house, or through a garage door.
Why stormwater blocks here more than most places
- Escarpment suburbs like Thirroul, Bulli, Austinmer and parts of Wollongong shed a huge volume of water very quickly into systems sized decades ago.
- Coastal sand and silt in Shellharbour, Shell Cove, Warilla and Flinders migrates into pits and settles in the low points of the line.
- Established gardens push roots into old PVC and earthenware joints, catching leaf litter until the line chokes.
- Leaves from gums and figs fill gutters and downpipes, then wash straight into the underground line as a mat of debris.
- Crushed or collapsed pipe from driveway traffic, landscaping or retaining wall work creates a permanent restriction that only shows up in heavy rain.
Stormwater or sewer? A quick way to tell
Stormwater overflows are clear or muddy, appear during or right after rain, and come out of surface pits, downpipes or the yard. Sewer overflows smell, contain paper or waste, appear when you use water inside, and come from the overflow relief gully near the house. If you have any doubt at all, stop using water inside and call us — treating a sewer overflow as a stormwater issue causes health risk and property damage.
What you can safely do yourself first
- Lift the grate on surface pits and scoop out leaves, sand and silt by hand.
- Clear gutters and check each downpipe discharges freely — pour a bucket of water down and watch for backing up.
- Check the outlet at the kerb or the legal discharge point for a blockage of leaves, sand or mulch.
- Photograph where water pools during rain — it tells us which section of line has failed.
How we clear and diagnose a blocked stormwater line
We jet the line with high-pressure water to cut roots and flush silt, then run a CCTV camera to confirm the line is actually clear and to find out why it blocked. The camera matters: clearing a blockage without seeing the cause means you're booking the same job again next storm. We locate defects to the metre from the surface, so if a section needs repair you know exactly where and how deep before anyone digs.
When clearing isn't the answer
If CCTV shows a collapsed section, a back-fall (pipe running the wrong way), a crushed length under a driveway, or an undersized line for the roof area it serves, jetting only buys time. Options then include a targeted dig-and-replace of the failed section, relining, adding pits to catch debris before it enters the line, or re-grading surface drainage so water moves away from the building.
Preventing the next flood
The homes we never see twice do three things: gutter guard or a scheduled gutter clean before storm season, silt pits kept clear through summer, and a CCTV check of the main stormwater line every few years if there are mature trees on the block. For properties with a history of water against the slab, a spoon drain, grated strip drain or agricultural drain behind a retaining wall often solves permanently what jetting only treats.
Council, neighbours and legal discharge
Stormwater has to go to an approved point of discharge. You cannot lawfully redirect it onto a neighbour's land, and inter-allotment drainage easements have specific obligations. If your issue is water arriving from uphill rather than leaving your own roof, we'll document what we find so you have something factual to take to the neighbour, the strata committee or council.
Frequently asked questions
- What's the difference between a blocked stormwater drain and a blocked sewer?
- Stormwater carries rain from roofs and surfaces to a legal discharge point and overflows clear water during rain. Sewer carries wastewater from inside the house, smells, and overflows when you use water indoors. They are separate systems and must never be connected.
- Why does my yard flood only in heavy rain?
- Usually a partially blocked or undersized stormwater line. It copes with light rain and overflows once inflow exceeds the restricted capacity, which points to silt, roots, a crushed section or a back-fall in the pipe.
- Can high-pressure jetting damage old stormwater pipes?
- Correctly controlled jetting is safe for sound pipe. Where CCTV shows fractured earthenware or a partly collapsed line, we adjust the method or recommend repair rather than pushing a failing pipe further.
- Do I need a CCTV inspection after clearing the blockage?
- We recommend it. Clearing restores flow, but only the camera tells you whether the cause was leaf litter, roots, a crushed pipe or a fall problem — which determines whether it will happen again.
- Who is responsible for a blocked stormwater line on my property?
- The property owner is responsible for stormwater pipework within the boundary up to the legal point of discharge. Council typically maintains the street system and kerb infrastructure.
- Can you redirect stormwater away from my house?
- Yes — spoon drains, grated strip drains, agricultural drainage behind retaining walls, additional pits and re-graded surface levels are all common fixes, provided water still reaches an approved point of discharge.
- Which Illawarra suburbs do you cover for stormwater work?
- Shellharbour, Shell Cove, Flinders, Warilla, Albion Park, Oak Flats, Dapto, Kiama, Gerringong, Wollongong and the northern escarpment suburbs.