Signs your stormwater isn't coping
- Downpipes overflowing at the bottom, or water spurting where they meet the ground.
- Pits or grates in the yard filling up and spilling over in rain.
- Puddles against the house walls, or water under the floor after a storm.
- Soggy lawn, sinking pavers or washed-out soil along a pipe line.
- Nothing coming out of the kerb outlet during heavy rain.
Stormwater is not the sewer
Homes on the sewer have two separate sets of drains. The sewer takes waste from toilets, showers and sinks to the water company's main. Stormwater takes rain from roofs, paths and yards to the kerb, a council drain, a soakwell or a tank, depending on the property.
That's why a blocked stormwater pipe tends to show up outside during rain, while a blocked sewer shows up at the gully or inside whenever you use water.
Who looks after a stormwater pipe beyond your boundary isn't the same everywhere. If the trouble seems to be in the street, ask your council or water company.
What usually goes wrong
Leaves and silt cause most stormwater blockages. Roots get into older pipes through the joints, as they do in sewers. Pipes under driveways can crack or crush, and some older homes have downpipes that were never connected to anything below ground.
Sometimes the pipe is intact and the problem is its fall: a pipe that runs flat, or rises, holds water and silt until it blocks.
What a plumber will do
A plumber will trace where each downpipe and pit drains to, then find the blockage with a camera or by working along the line.
Silt and leaves come out with a hydro jetter, which flushes the whole pipe. Broken or crushed sections are dug up and replaced, and a badly laid pipe may need a new fall or an extra pit.
If you'd like to keep the rain, a plumber can also look at sending downpipes to a rainwater tank.
What changes the job
- Where the water ends up: the kerb, a council drain, a soakwell or a tank.
- How far the pipe runs and how deep it sits.
- What covers it: lawn, garden beds, paving or a driveway.
- Whether there are pits to work from, or access has to be made.
- How many downpipes feed into the same line.
What you can do first
You can
- Clear leaves off grates and pit covers you can lift by hand.
- Have the gutters cleaned, so leaves don't wash into the pipes.
- Watch the yard in heavy rain and film where water pools or spills.
- Check whether each downpipe goes into the ground or just empties onto the surface.
Leave to a licensed plumber
- Clearing pipes underground, by jetter or drain machine.
- Cutting into, replacing or re-laying stormwater pipe.
- New pits, grates and downpipe connections.
- Anything close to the sewer line or the boundary.
Licences for stormwater work
Tasmania's plumbing regulations list "roof (stormwater)" as its own category of plumbing work, separate from sanitary, water and drainage work. In NSW, drainage is specialist work, which needs a contractor licence whatever the job costs.
Ask whether the plumber's licence covers stormwater, and check it on your state's register: our licence guide shows how. Certificate rules for drainage differ by state, so ask what paperwork you'll get if new pipe goes in, and see our compliance certificate guide.
Questions to ask the plumber
- Where does each downpipe actually drain to?
- Is it silt and leaves, roots, or a broken pipe?
- Can you show me on camera?
- Does your licence cover stormwater work in this state?
- Will the fix change where water leaves the property?
What we would do
Next time it pours, film the yard: where water pools, which downpipes overflow, and whether the kerb outlet runs. A minute of video tells a drain specialist more than any description, and it often points straight at the blocked section.