Stormwater pipes are the drains that carry rainwater away from your property, from gutters, downpipes, paths, driveways and garden areas, to the street drainage system or a natural waterway. Most homeowners think of blocked drains as a sewer problem, but stormwater pipe failure is just as common and can cause yard flooding, driveway ponding and structural damage to buildings if not addressed. Stormwater pipes can be relined just like sewer pipes, and it’s often the smarter, cheaper option.
The quick answer
Residential stormwater pipes can and should be relined when they’re cracked, root-infiltrated, or losing capacity due to internal deterioration. The process is the same as sewer relining: a CCTV inspection first, then a resin liner installed inside the existing pipe without excavation. Stormwater relining typically costs $3,000, $7,500 for a typical residential run on the Central Coast.
How stormwater pipes differ from sewer pipes
Understanding the difference is important for diagnosis. See our full guide on sewer vs stormwater: which pipe is blocked.
| Feature | Stormwater pipe | Sewer pipe |
|---|---|---|
| What it carries | Rainwater and surface runoff | Sewage and wastewater |
| Smell when failed | No smell (clean water) | Sewage odour |
| Signs of failure | Yard flooding, slow drainage | Gurgling, back-surge, odour |
| Connection | Street pits, creeks, kerb outlets | Council sewer main |
| Required liner type | Standard structural liner | Chemical-resistant liner |
| Pipe materials (older homes) | Clay, AC cement, old PVC | Clay, AC cement, old PVC |
Because stormwater pipes carry only rain water, they don’t smell when blocked or broken. This is partly why stormwater problems go unnoticed for longer, there’s no sewage odour to prompt action. The only signs are water-related: flooding, ponding, wet spots in gardens, or water entry to garages.
Signs your residential stormwater pipe needs relining
Yard flooding after rain
If your yard floods in moderate rainfall (not just extreme events), the stormwater drainage system isn’t coping. The cause is usually:
- Root intrusion reducing the pipe bore
- Sediment or debris blockage
- Pipe collapse restricting flow
- Disconnected or offset joints creating a dam point
Driveway or path ponding
Stormwater pits and pipes under driveways are frequently root-invaded. When the pipe bore reduces to 50% or less of original diameter, the pit can’t drain fast enough and the surface ponds.
Water entry to sub-floor or garage
On properties where a stormwater pipe runs alongside or under a structure, a failed pipe can cause water to track along the pipe trench and enter through a sub-floor vent or floor junction.
Wet patches in garden with no irrigation leak
If you have a consistently wet patch in the garden that doesn’t correspond to an irrigation leak, a leaking stormwater pipe may be discharging groundwater into the surrounding soil.
Repeated pit cleaning that doesn’t solve the problem
If a contractor cleans your stormwater pit and pipes but the flooding recurs after the next rainfall, root intrusion is almost certainly the cause. Cleaning removes roots temporarily, relining removes roots permanently.
How stormwater drain relining works
The process for residential stormwater relining follows the same steps as sewer relining:
1. CCTV inspection
A camera fed through the stormwater system maps the pipe diameter, material, defect locations, root intrusion and gradient. This is essential before any relining decision.
2. Hydro jetting
High-pressure water cleaning clears the pipe of roots, silt, leaves and debris. On older clay stormwater pipes, this needs to be done carefully to avoid fragmenting already-compromised sections.
3. Liner installation
A resin-impregnated liner is pulled or inverted into the pipe and inflated against the pipe wall. Stormwater liners don’t require the chemical resistance of sewer liners, but they still need to be structural, they’re carrying water under pressure during rainfall events.
4. Curing
The resin cures to form a rigid new pipe. For stormwater pipes, UV cure is common as it’s fast and unaffected by the wet environment inside the pipe.
5. Junction reinstatement and final CCTV
Branch connections are opened by robotic cutter if applicable. A final CCTV confirms installation quality.
Common stormwater pipe scenarios in Central Coast homes
| Scenario | Recommended action |
|---|---|
| Old terracotta stormwater pipe, root-invaded | CCTV + full relining |
| AC cement stormwater pipe, joint gaps | CCTV + relining or point repairs |
| PVC stormwater from 1990s, partially crushed under driveway | CCTV + stormwater reline |
| Stormwater pit not draining, pipe unknown condition | CCTV to diagnose, then reline if indicated |
| Downpipe connection broken underground | Point repair or short section reline |
Stormwater relining under driveways: the no-dig advantage
Many residential stormwater pipes run under concrete driveways. When these pipes fail, the traditional repair means breaking the driveway, replacing the pipe, and reinstating the concrete. The cost and disruption are significant.
Stormwater drain relining under a driveway eliminates the need to break any concrete. The liner is accessed from a pit at either end and installed through the existing pipe from inside. No concrete cutting, no temporary loss of driveway access. See our dedicated guide on drain relining under driveways.
2026 residential stormwater relining costs on the Central Coast
| Job type | Typical price range |
|---|---|
| CCTV inspection (stormwater) | $250, $450 |
| Hydro jet clean + CCTV | $350, $600 |
| Point repair (single stormwater defect) | $750, $1,600 |
| Full stormwater reline, 10-15 m | $2,800, $5,000 |
| Full stormwater reline, 15-25 m | $4,500, $7,500 |
| Combined sewer + stormwater reline | $7,500, $15,000+ |
Stormwater relining is often slightly cheaper than equivalent sewer relining because the liner doesn’t need the same chemical resistance. However, access and diameter can still significantly affect price. See the full 2026 cost guide for more detail.
Should you reline stormwater pipes before a major rain event?
If you’ve had flooding problems in previous wet seasons, relining before the next major rain is sound planning. On the Central Coast, the wettest months are typically June through September, with La Niña events creating periods of sustained heavy rainfall. A CCTV inspection in autumn is a sensible preventive measure for any property with older stormwater infrastructure.
Stormwater relining vs replacement: the comparison
| Factor | Relining | Excavation and replacement |
|---|---|---|
| Cost | 40-60% less | Baseline comparison |
| Driveway damage | None | Concrete breaking + reinstatement |
| Garden disruption | None | Excavation along pipe route |
| Duration | 1 day | 2-5 days |
| Result service life | 50+ years | 50+ years |
| Council approval | Generally not required | Sometimes required |
Frequently asked questions
Can I reline stormwater pipes that go under my pool? Yes. Relining is the only practical repair method for stormwater pipes that run under a pool surround. Excavating under a pool is structurally risky and extremely expensive.
What diameter are residential stormwater pipes? The most common residential stormwater pipe diameters are 90 mm, 100 mm and 150 mm. Some older properties have 75 mm drainage that may need to be upsized if capacity is an issue.
Will the council help pay for stormwater relining? No, residential stormwater pipes within the property boundary are the owner’s responsibility. Pipes in the street are the council’s responsibility. If your pipe failure is connected to a council pipe failure, there may be a conversation to have, but don’t assume it.
How long will a relined stormwater pipe last? The same as a relined sewer pipe, 50+ years in residential conditions, with a typical warranty of 25-35 years.
Can I reline a damaged downpipe connection underground? Yes. Short sections and point repairs work well for repairing the underground section of a downpipe connection. Above-ground downpipes are separate, if they’re damaged or undersized, they can be replaced relatively cheaply.
Have stormwater flooding problems? Book a CCTV inspection or get a relining quote.