Oasis Soakwells
Stormwater Installation and Drainage Design in Perth
Every drop of rain that lands on your roof and paving needs somewhere safe to go. Stormwater installation gives it that path: a system of grates, pipes and soakwells that collects the runoff and returns it to the ground on your property. Done properly, it helps prevent flooding and protects your home, garden and neighbours for years to come.
Oasis Soakwells is a family-owned Perth business with ten years’ experience in stormwater drainage. We take on everything from a single storm drain installation on a new patio to complete stormwater drainage systems for new homes, from Yanchep to Mandurah.
Why Stormwater Drainage Matters in Perth
Perth’s sandy soils drain well, but they can’t absorb a winter downpour all at once, especially when it pours off a roof or driveway in one spot. When backyard stormwater drainage isn’t up to the job, you’ll often see:
Standing water on lawns and paving after heavy rain
Erosion that washes out garden beds and paths
Pavers and concrete sinking as the ground beneath them shifts
Water pooling against walls or running into garages
Stormwater runoff flowing onto your neighbours’ land or into the street
Seeing any of these?
That’s why most Perth councils require you to keep stormwater within your property. Most homes do it with soakwells. A stormwater pit holds water temporarily until it flows on to a drain, while a soakwell releases it slowly into the surrounding soil.
Managing stormwater on site also means less runoff carrying fertilisers, oil and heavy metals into Perth’s rivers, lakes and wetlands. It’s the thinking behind water-sensitive urban design: slow the water down, limit hard surfaces and let the soil and plants filter it.
Stormwater Drainage Design Built Around Your Property
No two blocks drain the same way, so every system we design starts from scratch. We begin with your council’s recommendations, which are based on local storm data, and use them to determine what your property needs. If it needs more than the council recommends to hold up long term, or less, we’ll tell you why and lay out your options.
Every design weighs up:
Hard surfaces
More roof and paving means more runoff, and smaller Perth blocks leave less open ground to absorb it.
Soil type
Different soil types, like sand, clay and limestone, drain at very different rates.
Slope and groundwater
The fall of your land and the winter water table shape where soakwells can go and how deep.
Overflow
No system absorbs every storm, so we plan for the one that fills it. We generally recommend a grate beneath each downpipe rather than a direct connection. If a soakwell fills, water overflows at ground level instead of backing up into your gutters and roof.
On slopes and large paved areas, channel grates catch surface water before it reaches your garage or house. We handle rainwater drainage installation for new homes, renovations, patios, granny flats and pools.
Building a new home? Send us your plans and we’ll design and install a system to suit.
What’s Involved in Stormwater Installation
Every stormwater installation follows the same careful steps, whatever the size of the job.
01
A figure to work from
Call us or send your plans for an estimate. If either of us is unsure about the job, we’ll arrange a site visit. You’ll know the likely costs before installation day. If hard ground like limestone or clay adds cost once we’re digging, we’ll tell you before doing the extra work.
02
Careful excavation
Around underground service lines, we dig trenches by hand with shovels, not excavators. We also take on the jobs others avoid, like concrete cutting, digging through clay and tight-access sites.
03
Stormwater pipe installation
Pipes run from your downpipes and grates to the soakwells with a consistent fall, the gentle slope that keeps water moving.
04
Soakwells at sufficient depth
We install polypropylene and concrete soakwells and recommend the right one for your site. Each is wrapped in geotextile fabric to keep sand out, properly bedded and set deep enough for what sits on top.
05
Backfill and compaction
We compact the backfill with both water and plate compaction. Skipping this leaves air pockets that fill with rain, so the ground sinks and paving above becomes unstable.
06
Optional finishing services
We can take the excess soil away and reinstate your pavers or artificial grass. Both are additional services, charged separately.
Every new soakwell we install is backed by our 25-year guarantee.
Looking After Your Stormwater System
A little regular maintenance keeps your system working. Keep gutters, grates and channel drains clear of leaves. Most soakwells can’t be reached for cleaning, so if one drains slowly or water pools after rain, book a free soakwell health check. We’ll tell you whether it needs cleaning, a repair or replacing.
Frequently Asked Questions
It depends on what sits on top. We install soakwells with 200mm to 300mm of cover under lawns and garden beds, and 500mm under driveways. More cover makes a stronger soakwell. Depth also sets the fall of the pipes feeding the soakwell, so getting it right is essential.
You can, and in Perth’s sandy soil it will soak up a little water. It’s no match for runoff from a roof or paving, though. The gravel fills most of the hole, so it holds far less water than a soakwell of the same size. Over time, sand and silt wash into the gaps until it stops draining. For roof water, a properly sized soakwell is the reliable solution.
On a house block, stormwater pipes need more cover under driveways than they do in garden areas. In practice, the fall usually decides the depth. Pipes must run steadily downhill to the soakwell, so on a flat block, the longer the run, the deeper the far end sits.
Yes. Roof water has to discharge into a stormwater system on your property, which in Perth usually means a soakwell. It must never go into the sewer, as sewer and stormwater drains are separate systems. We generally recommend a grate beneath each downpipe rather than a pipe fixed straight on. If a big storm fills the soakwell, water overflows at ground level instead of backing up into your roof. Under patios, where water can splash out of a grate, we may use an adaptor, provided the system has a grate elsewhere and an outside escape for overflow.
Not in Western Australia. Stormwater drainage isn’t regulated plumbing work in WA, so it doesn’t need a licensed plumber the way sewer, wastewater and water supply work do. It does need someone who knows Perth soils and council requirements. Getting the size, depth, falls and compaction right is specialist work, and it’s what we’ve focused on for ten years.
It depends on where the water comes from and your soil. For most Perth backyards, soakwells are the most effective option, collecting runoff from your roof and paving and letting it soak into the sandy soil. Channel grates, a type of surface drainage, use a shallow grated channel to catch water running across paving or down a slope. We’ll recommend the right mix for your yard.
Your local council sets the rules, and each council has its own. They include keeping stormwater within your boundary and setting soakwells back from buildings. We check what applies to your property and design every system around your council’s recommendations.