Soakwell Installation Services WA 2026 - Get Quotes

What a Soakwell Actually Does

A soakwell is a buried chamber with an open or perforated structure that receives stormwater and lets it infiltrate into the surrounding soil. Rain falls on the roof, runs into the gutters, down the downpipes and through underground pipework into the wells, where it soaks away rather than running across the ground or out to the street. On the sandy soils that cover most of the Perth metropolitan area this works extremely well, because sand accepts water quickly and the aquifer beneath is recharged in the process. The drainage guide for WA puts soakwells alongside the other options used across the state. It is a simple idea that works because of what the ground here is made of. Try the same approach on Sydney clay and it performs very differently.

The reason this is the standard here rather than kerb discharge is a combination of geology and policy. Piping every property's roof water into the street drainage network would require a far larger public system than the one that exists, and the sand makes on site disposal both practical and beneficial. Local governments across Perth therefore require new dwellings, additions, patios, sheds and paving to dispose of their stormwater within the property boundary. It is a requirement rather than a recommendation, and it is checked as part of the building approval process. The volumes involved are substantial, since a single storm on a two hundred square metre roof produces thousands of litres in an hour.

What a soakwell is not is a septic tank or a sealed tank, and the confusion is common enough to be worth stating. A soakwell is designed to let water out through its walls and base into the soil, so it is perforated or built with open joints and surrounded by free draining material. A rainwater tank stores water for reuse and is entirely sealed, and the two serve different purposes. Some households run both, taking the first flush to a tank and the overflow to soakwells, and the rainwater tank plumbing page covers that arrangement.

The performance of a system depends on two things working together, which are storage volume and infiltration rate. The wells need to hold enough water to accept the runoff from a design storm without overflowing, and the surrounding soil needs to accept that water at a reasonable rate so the wells empty again before the next downpour. In deep sand the infiltration is excellent and storage is the limiting factor. Where clay or a high water table is present, infiltration becomes the constraint and a larger system may not solve the problem on its own. Understanding which of the two is limiting your system determines whether adding another well will help.

Most Perth households only discover their soakwells exist when something goes wrong. Water pooling against the house after rain, a section of lawn that stays saturated for days, paving that has dropped in one spot, or a downpipe that surcharges and spills across the patio are the usual signals. Each of those points to a different underlying cause, and diagnosing which one matters before spending money. An older house with wells installed decades ago is often carrying a system that no longer meets current requirements. That is not necessarily a problem until something changes, but it becomes one as soon as a patio or a shed is added.

Retrofitting soakwells to an older property is common work across Perth. Homes built before on site disposal was enforced consistently sometimes have nothing at all, with downpipes simply discharging onto the ground beside the house, and that creates exactly the damp conditions that damage footings, feed termites and cause paving to move. Adding wells to such a property is usually straightforward where there is access, and it addresses several problems at once. Owners often find the damp patch beside the wall disappears within one wet season. It is also one of the more useful things an owner can do to a Perth house. Keeping roof water away from the base of the walls protects footings, reduces termite pressure and stops paving moving.

How Councils Size the System

The volume of storage a property must provide is set by the local government, and while the approach is broadly similar across the metropolitan area, the specific figures differ from one council to another. The calculation generally works from the total impervious area, meaning the roof plus paved surfaces such as driveways, patios and paths, multiplied by a design rainfall event. The result is expressed in litres or cubic metres of required storage. Your council's technical standards or a phone call to their engineering section will give you the number that applies.

Understanding the units avoids a common confusion when comparing quotes. Soakwells are usually described by diameter and depth, such as a 900 by 900 or an 1800 by 1200, and each of those has a nominal storage capacity in litres. A quote offering four 900 by 900 wells and one offering two 1500 by 1200 wells may provide quite different total storage, and the only way to compare them is to convert to litres. Suppliers publish the capacity of each size, so the arithmetic is straightforward once you have the figures. Ask each contractor to state the total storage volume the system provides. Without that figure, comparing two quotes is guesswork. It is the single question that sorts a considered quote from a rough one.

Impervious area is the input that owners most often get wrong, because it is easy to forget the additions. The roof of the house is obvious, but the garage, the patio, the alfresco, the shed, the driveway, the paths and any paved courtyard all contribute runoff and all count toward the calculation. A property that had adequate soakwells when built may be badly undersized after a patio, a shed and a paved entertaining area have been added over twenty years. That is one of the most common reasons an established home starts having drainage problems. Nothing has failed, the system has simply been asked to handle more than it was built for. Adding storage rather than replacing the existing wells is usually the fix.

New builds and additions handle this as part of the approval process. A building permit application for a new house, an extension, a patio, a shed or substantial paving will require the stormwater disposal to be shown and sized, and the certifying process checks it. Owner builders and anyone commissioning work should confirm what has been specified before the slab goes down. Builders occasionally provide the minimum the approval required rather than what the finished property will eventually need. Where a patio or verandah is being added, the additional roof area generally triggers a requirement for additional storage. The same applies to a shed, which the shed and garage construction page covers.

Oversizing modestly is usually worth it and undersizing never is. The incremental cost of one extra well at installation is small compared with returning later to dig up a lawn or lift paving, and Perth does get intense short duration downpours where the storage volume matters more than the infiltration rate. Where the budget allows, building in some headroom for a future patio or shed is sensible. A contractor who suggests this is thinking ahead, not padding the quote. One extra well while the machine is on site costs a fraction of bringing it back. Mobilisation is a real cost on any excavation job.

Regional Western Australia works differently and the metropolitan approach does not transfer automatically. Towns with clay soils, high water tables or different rainfall patterns may require detention rather than infiltration, connection to a piped network where one exists, or other arrangements entirely. In the south west and the Great Southern, heavier soils change what is achievable. Always check with the specific local government, since what a Perth contractor is used to may not apply.

Concrete, Poly or Crates

Precast concrete soakwells have been the WA standard for decades and remain the default on many jobs, and local precasters supply them in a standard range of diameters and depths. They are strong, they hold their shape under load, they last a very long time in the ground, and with the correct lid they can sit under a driveway or a parking area. The weight is the constraint, since a large concrete well needs machine handling to place, which makes access down the side of a narrow block the deciding factor. On a typical suburban lot with side access they are usually the sensible choice. They are also the product most WA contractors have worked with for years, which shows in the quality of the installation.

Polypropylene and polyethylene soakwells have taken a significant share of the market and for good reasons. They are light enough to be carried through a house or over a fence, they install quickly, and they suit tight access sites where a machine cannot reach. Australian suppliers such as Everhard and Reln produce ranges widely stocked across Perth. The trade offs are that the load rating matters a great deal more, the backfill has to be placed and compacted correctly to support the walls, and a poly well under a driveway needs to be a product rated for that use with the correct lid. Used within their rating they perform well and there is nothing second rate about them. The failures attributed to poly wells are almost always installation failures, not product failures. Backfill and lid rating are where those installations go wrong.

Modular stormwater crates are the third option and they solve a particular problem. Where storage is needed in a shallow profile, such as over a high water table or under a driveway with limited depth available, crate systems provide high void ratio storage in a wide flat footprint. They are wrapped in geotextile to keep soil out and assembled to the volume required, which makes them flexible on awkward sites. Brands used in Australia include Atlantis and StormTech, and the systems are more common on commercial work than on houses. They cost more per litre than concrete or poly and are less common on straightforward domestic jobs, but on a constrained site they are sometimes the only workable answer, particularly where a high water table limits how deep anything can go.

Lids are where a great many Perth soakwells fail and the detail is worth pressing. A standard lid is designed for pedestrian traffic and garden loading only, and it will crack the first time a vehicle drives over it. Where a well sits under a driveway, a parking bay, a caravan pad or anywhere a vehicle might go, a trafficable lid rated for that load is required. The cost difference at installation is modest and the cost of a collapsed lid under a driveway is not. It also creates a genuine safety hazard once the lid gives way and the surface above opens up.

Silt pits are an addition worth considering and they are often omitted. A silt pit sits between the downpipes and the soakwells, catching sand, leaf litter and debris before it reaches the well, and it has an accessible lid so it can be emptied. Because Perth sand travels readily and leaf litter comes off every roof, wells without a silt trap gradually fill with material that reduces their capacity. Cleaning a small silt pit is a simple job while cleaning a silted soakwell is not. On a property with mature trees or a tile roof shedding grit, it pays for itself within a few years. It also makes the condition of the system visible without excavation.

Rubble pits deserve a mention because they still appear occasionally. A pit filled with rubble or blue metal provides some storage in the voids between the stones and was once common practice, but the void ratio is poor, it silts up over time and it generally does not satisfy current council requirements. Finding one on an older property usually means the system needs replacing, and adding to it will not help. They are still occasionally encountered on properties from the 1960s and 1970s. A contractor proposing a rubble pit on a new job is offering something that will likely not be approved.

Ground Conditions and Placement

Depth to groundwater is the first site condition that matters, and across Perth it varies enormously. In parts of the coastal suburbs and the low lying areas near wetlands the water table can be within a couple of metres of the surface, particularly through winter, and a soakwell installed below it will be sitting in water permanently and will never drain. Councils generally require clearance above the winter groundwater level for this reason. A contractor who asks about water table or checks local information before quoting understands this. Perth's groundwater levels are mapped and publicly available, so there is no excuse for guessing.

Limestone is the second condition and it is a distinctly Perth problem. Large parts of the coastal suburbs sit on Tamala limestone, sometimes just below the sand and sometimes at the surface, and excavating a soakwell hole through cap rock requires a rock breaker, and a bucket will not touch it. That turns a two hour excavation into a much longer and more expensive one. Quotes in those suburbs should carry a provisional allowance for rock, and a contractor who has worked in Sorrento, Hillarys, Trigg or Wembley Downs will raise it before you do. Rock also limits how deep the wells can go, which sometimes means more wells instead of deeper ones. That changes the footprint required on a small block.

Clay is the opposite problem and it appears more than people expect. Pockets of clay through parts of the eastern and southeastern suburbs, and more widely in the hills and in regional areas, do not accept water at anything like the rate sand does. A soakwell installed into clay fills during a storm and then sits full for days, which means it cannot accept the next downpour. Where clay is present, the answer may be a larger system, a different depth to reach a more permeable layer, or a different disposal approach entirely. The french and subsoil drainage page covers the alternatives used where infiltration is poor.

Setbacks from buildings matter for structural reasons, not bureaucratic ones. A soakwell placed too close to a footing saturates the ground beside it, which can undermine the footing on sand and cause movement, and it also puts water right where you least want it on a timber framed structure. Councils set minimum distances from buildings and boundaries, commonly in the order of a metre or more depending on the authority. It is also worth keeping wells clear of the termite inspection zone around the slab edge, since that strip needs to stay visible and dry. Saturating the ground beside a slab is exactly the condition termites favour. The two issues are more connected than most owners realise.

Boundaries, easements and services all constrain where wells can go. A soakwell cannot sit over a sewer easement or a water main, it needs to be clear of the neighbour's boundary by the required setback, and it must not discharge in a way that directs water onto adjoining land. Underground services should be located before excavation, which is standard practice on any dig. Where a property has a septic system or leach drains, additional separation applies and the local government will specify it.

Trees are a practical consideration that catches people out years later. Roots seek water and will find a soakwell, entering through perforations or joints and progressively filling the void, and large species planted near a well will eventually cause a problem. Keeping wells away from established trees, or from where trees are planned, avoids that. Where roots have already invaded a system, the pipe relining and drain repairs page covers the options for the pipework side of it.

Access for the machine is the last practical constraint and it decides the material choice on many jobs. A three tonne excavator needs roughly a metre and a half of clear width, a solid surface to travel on and no low obstructions, and on many Perth infill blocks that simply does not exist. Where access is impossible, options include removing a fence panel temporarily, hand digging at considerably greater cost, or choosing poly wells that can be carried in. Hand digging is genuinely expensive and is usually a last resort. The excavation and earthmoving page covers what different machines need. Walking the access route with the contractor before booking avoids an unpleasant discovery on the day.

How the Installation Runs

A typical soakwell job follows a clear sequence and most residential installations take one to two days. The positions are marked out with setbacks and services confirmed, the holes are excavated, the wells are placed and levelled on a compacted base, the connecting pipework is laid from the downpipes with fall toward the wells, the system is backfilled and compacted, lids are fitted and the surface is reinstated. Where paving or lawn has been lifted, reinstatement is the final stage and it is worth confirming who does it.

Excavation generates a surprising volume of spoil and it has to go somewhere. Each cubic metre of soakwell means roughly a cubic metre of sand out of the ground, and on a multi well system that is a substantial pile. Owners are frequently surprised at how much material comes out of what looks like a modest hole. Some of it goes back as backfill, but the excess needs removing or spreading, and the quote should say which. Where it is being carted away, disposal is usually included, and the rubbish removal page covers the alternative of arranging it separately. On a tight block there also needs to be somewhere to stockpile the sand while the wells go in.

Connecting the downpipes properly is where the difference between a good and poor installation often shows. Stormwater grade pipe rather than agricultural pipe, adequate fall from the downpipe to the well, sealed joints, and a sensible layout that avoids long runs across the property all matter. Where multiple downpipes feed one well, the pipe size has to carry the combined flow. The gutter and downpipe installation page covers the above ground side of the same system. A blocked or undersized downpipe limits the whole arrangement regardless of how much storage sits below it. Gutter capacity is part of the same chain.

Backfill and compaction are not optional details, particularly around poly wells. The material placed around the well supports its walls against the surrounding ground pressure, and poorly compacted backfill allows the well to distort or the surface above to subside over the following year. Clean sand placed in layers and compacted is the usual specification. This is also why paving over a newly installed well is best left until the ground has settled through a wet season if timing allows.

Overflow arrangements deserve a question because Perth does get storms beyond any design event. A properly considered system has a defined overflow path so that when the wells are full, water goes somewhere harmless rather than pooling against the house or flowing to a neighbour. That might be a surcharge point in the garden, a path across the lawn or a connection to a secondary well. A contractor who has thought about where the water goes in an extreme event is designing the system, not just installing it.

Reinstatement is the part that owners see and judge. Lawn areas will need topsoil and either turf or seed, paved areas need the pavers relaid on a properly compacted base rather than dropped back into loose sand, and concrete that has been cut will need patching or replacing. Agree beforehand who is responsible for each of those, since a drainage contractor may or may not include paving reinstatement. The paving and driveway installation page covers what good reinstatement involves. Pavers dropped back onto loose sand will settle unevenly within a year.

Timing matters more than people expect. Winter is when problems become obvious and when everyone rings, so lead times stretch from May onwards, and working in saturated ground is harder and messier. Booking in late summer or autumn means better ground conditions, a faster start and a system that is ready before the rain arrives. It is one of the clearer cases where planning ahead saves both money and inconvenience.

Why Soakwells Fail

Silting is the most common cause of a system that worked once and no longer does. Sand washed off paving, grit from a deteriorating tile roof and leaf litter from gutters all travel down the pipework and settle in the base of the well, progressively reducing the storage volume until the system surcharges in ordinary rain. On a Perth block with mature trees this happens faster than most owners expect. A silt pit prevents most of it and regular gutter cleaning prevents much of the rest. Both are cheap compared with excavating and cleaning a full well.

Undersizing is the second cause and it is usually the result of additions over time. A system sized for the original house does not have the capacity for the house plus a patio, a shed, an extended driveway and a paved alfresco, and the symptoms appear gradually as each addition is made. Owners often blame the wells for failing when the wells are simply too small for the area now draining into them. Recalculating the impervious area is the first step when diagnosing this.

Collapsed lids are a frequent and entirely avoidable failure. A standard lid driven over by a car, a delivery van, a trailer or a caravan will crack, and once it collapses the well fills with soil and stops working entirely. It is also a genuine safety hazard, since a person or a pet can fall into an open well. Where vehicles use an area, a trafficable lid is the answer and it should have been specified at installation. Retrofitting one means excavating the well again, which is why getting it right the first time matters.

Downpipes that were never connected are more common than anyone would guess. On plenty of Perth properties one or two downpipes discharge onto the ground or into a short stub that goes nowhere, either because the original installation was incomplete or because a later renovation disconnected them. The water then soaks in beside the house rather than into the wells, and it is a frequent contributor to damp problems, paving movement and termite pressure. Walking the house during heavy rain and watching each downpipe is the simplest diagnostic available. It costs nothing and it routinely finds the actual problem. Take a video while you are out there.

Root intrusion builds up slowly and shows up as reduced capacity. Roots entering through perforations or pipe joints fill the void and block the flow path, and the species most responsible are the large trees planted close to the house in older suburbs. Clearing roots restores some capacity but the problem returns unless the tree or the well is relocated. This is one of the reasons setback from established trees is worth respecting at installation.

Groundwater is the failure that nothing can fix without a different approach. Where the winter water table rises to the level of the well, the well is already full before the rain starts and has nowhere to send the water. Owners in low lying suburbs sometimes find their system works perfectly from November to May and fails every winter, which is the signature of this problem. The answers involve raising the system, adding shallow wide storage, or in some cases a pumped arrangement in place of pure infiltration. None of those are cheap, which is why identifying the cause before spending matters.

Approvals, Licensing and Rules

Stormwater disposal is regulated at local government level in Western Australia and the requirements vary between councils. New dwellings, additions, patios, sheds, garages and significant paving all generally require stormwater disposal to be provided and shown in the approval documents. Replacing an existing failed soakwell like for like often does not require an approval, while adding a new system or increasing capacity may. A phone call to your council's building or engineering section settles the question quickly.

Building permits interact with this in a way worth understanding. Where a soakwell system forms part of a building approval, such as for a new house or a patio, it is assessed as part of that application and inspected accordingly. Standalone drainage work on an existing property is usually simpler, but the sizing requirement still applies if the council checks. Keeping documentation of what was installed and the storage volume provided protects you at resale. A buyer's building inspector may well ask about stormwater disposal. Having the paperwork removes the question entirely.

Plumbing licensing applies to parts of this work and not others. Connecting stormwater to a property's drainage where it interacts with the sewer or the scheme plumbing is licensed plumbing work, and a licensed plumber must carry it out. Pure stormwater soakwell work on private property is often carried out by drainage and earthmoving contractors, which is legitimate, but any interface with the sanitary plumbing is not. The stormwater drainage plumbing page explains where the line sits. Ask which parts of the job require a licensed plumber and who is doing them.

Discharging water onto a neighbouring property is not permitted and it is a common source of disputes. A system that overflows across a boundary, a downpipe directed at a fence line or a regraded surface that sends water next door can all give rise to a complaint, and local governments do act on them. Getting the overflow path right at design stage avoids the issue entirely. Where a dispute has already arisen, the local government is generally the first point of contact.

Environmental considerations apply in some locations more than others. Infiltrating stormwater recharges groundwater, which is generally beneficial, but in areas near public drinking water source areas or environmentally sensitive wetlands there can be additional requirements about what may be discharged. The Environmental Protection Authority and the state water regulator publish guidance relevant to larger developments. For a domestic soakwell on an ordinary suburban lot these considerations rarely bite, but they are worth knowing about near sensitive areas.

Consumer protections apply as with any trade service. Under the Australian Consumer Law the work carries a statutory guarantee of due care and skill, administered by the ACCC, and a system that does not perform as specified is a legitimate basis for a claim. Excavation work also carries safety obligations administered by WorkSafe WA, including around excavation stability and locating underground services. An open excavation on a residential property also needs to be made safe overnight, particularly where children or pets are around. Keeping the quote, the plan and the invoice makes any later conversation straightforward. Photographs of the open excavation are worth more than any of them.

Costs in Detail

A site assessment with sizing calculation runs $150 to $380 and is often absorbed into the job if you proceed. It establishes the impervious area, checks the council requirement, identifies access constraints and notes any limestone or groundwater issues. That combination is what turns a guess into a specification. On a straightforward job many contractors will quote from a site visit without charging separately. Where a property has an existing problem that needs diagnosing, paying for the assessment is money well spent. It is cheaper than installing the wrong solution, which is the usual outcome of guessing.

Poly soakwells supplied and installed run $320 to $780 each depending on size, depth and access, while precast concrete units run $480 to $1,100 each. The per unit figure is only meaningful alongside the storage volume, since a small well and a large one differ considerably in both price and capacity. Trafficable lids add $180 to $460 per well over a standard lid. Rock excavation where limestone is encountered adds substantially and should be a stated provisional rate, not an open ended variation.

Connecting downpipes runs $95 to $220 per run in stormwater grade pipe, depending on the distance and whether the route crosses paving or lawn. Long runs from a downpipe at the front of the house to wells at the rear cost more simply through the metres of pipe and trenching involved. Where paving has to be lifted and relaid over the pipe route, that is usually quoted separately and should be confirmed in writing. A silt pit installed ahead of the wells typically adds $250 to $650 and is worth it on most properties.

A full system on a typical Perth block commonly lands between $2,400 and $6,500. That covers the number of wells required for the roof and paved area, the connecting pipework, lids and basic reinstatement, and the spread reflects house size, access, ground conditions and how much paving has to be lifted. Larger homes, properties with extensive paving and blocks with limestone or poor access sit above that. Two storey homes with more roof area generally need more storage than single storey ones, though the footprint is often smaller than people assume.

Repair and maintenance work has its own figures. Cleaning out a silted soakwell runs $280 to $650 depending on access and how much material has accumulated, replacing a collapsed well runs $650 to $1,400, and locating a buried well on a property where nobody knows where they are can add a couple of hundred dollars of investigation. Root clearing from pipework is priced separately. On an older property, the honest assessment is sometimes that replacement costs less than repeated cleaning. A contractor who says so is giving you useful advice.

Regional pricing reflects travel and machine mobilisation. Contractors in Bunbury, Busselton, Albany, Geraldton and the Wheatbelt service their own areas, while mobilising an excavator to a remote property carries a real cost that is usually quoted separately. Ground conditions in regional WA also differ considerably from Perth sand, and clay soils change both the design and the price. Grouping work with a neighbour shares the mobilisation cost, which is common practice in country areas.

What to Look Out For

Be cautious of a quote that does not state the storage volume in litres. Soakwell sizing is a council requirement calculated from your roof and paved area, and a quote offering a number of wells without saying what volume they provide has skipped the only figure that determines whether the system works. Ask for the total storage and the council requirement it meets. A contractor who works in your area will have both to hand without needing to look them up.

Watch for standard lids where vehicles will drive. A lid rated for pedestrian loading will crack under a car, and the failure fills the well with soil and creates a hole in your driveway. The upgrade cost at installation is modest and the replacement cost is not. Identify every area where a vehicle, trailer, caravan or delivery van might go and make sure those wells are specified accordingly.

Be careful about limestone being treated as a surprise. Large parts of coastal Perth sit on cap rock and any contractor who works those suburbs knows it, so a quote with no allowance for rock in Hillarys or Sorrento is either optimistic or planning a variation. Ask what the rate is if rock is encountered and at what depth they expect it. A clear answer before the machine arrives prevents an awkward conversation once it is on site.

Check that every downpipe is actually being connected. It is remarkably common for one or two on a property to discharge onto the ground, and adding new wells while leaving them unconnected wastes part of the investment. Walk the house with the contractor and count the downpipes against what the quote covers. Doing this during rain is even better, since you can see exactly where the water is going. Five minutes in a downpour is worth an hour of speculation.

One last thing to settle: agree the reinstatement in writing before work starts. Excavating for soakwells disturbs lawn, garden and sometimes paving, and whether the contractor returns the area to its previous condition or simply backfills and leaves is the difference between a tidy job and a mess. Ask specifically about turf, topsoil, paving relaid on a compacted base and removal of excess sand. It is the part of the job most often left vague and most often complained about.

How to Get Comparable Quotes

Start by working out your numbers. Measure the roof area, including the house, garage, patio and shed, and add the paved surfaces, since the total impervious area is what drives the sizing. Ring your local government and ask what storage volume they require for that area and what setbacks apply. Arriving at the quoting stage with those figures means every contractor is pricing the same system instead of their own estimate of it.

Hand each contractor an identical written brief. Total storage volume in litres and the council requirement it satisfies, the number, size and material of wells proposed, lid ratings and which wells are trafficable, whether a silt pit is included, how many downpipes are being connected and in what pipe, excavation allowance if limestone is encountered, where the overflow goes, what happens to the excess sand, what reinstatement is included and the warranty on both materials and workmanship.

Compare the storage in litres, since the well count on its own means nothing. Two quotes can propose different numbers of different sized wells and deliver the same or quite different capacity, and only the litres figure makes that visible. Where one quote is materially cheaper, check whether it provides less storage, uses standard lids where trafficable ones are needed, or excludes reinstatement. Those three account for most of the gap in practice.

Keep a record of where everything is. Photograph the wells and the pipe runs before they are backfilled, note the positions relative to fixed points such as the house corner or a fence post, and keep the plan showing the layout and storage volume. In fifteen years, when a well needs cleaning or a paving project needs to avoid them, that record saves an afternoon of probing the lawn. It also answers a building inspector's question at sale time without anyone having to dig.

A correctly sized system with trafficable lids where they are needed, a silt pit and every downpipe connected will handle Perth rain for decades with nothing more than occasional cleaning. What decides that is the sizing calculation and the detail rather than the brand of well, and both are settled before anyone digs. Getting the impervious area right and the council requirement confirmed is the single most useful thing an owner can do before asking for prices. Get the impervious area and the required storage volume settled, and the rest of the decisions on this page become straightforward.