Is Mosman Park inside your area?

Yes. It’s the southern edge of our western-suburbs run, and we don’t go past it or south of the river. It’s a long drive from Ellenbrook, so ring and we’ll tell you honestly when we can get there.

The drains in our Peppermint Grove house keep blocking. Could it be the trees?

Quite possibly. Roots from established trees find their way into older drains through cracks and joints. We clear them with the hydro jetter, and a drain camera shows where they’re getting in, so you can decide what to do about that section.

A shared drain in our Cottesloe apartment block is blocked. Who organises the plumber?

Usually the strata manager, because shared stacks and drains are generally common property. We take bookings from strata managers and owners, and we’ll be clear about where the blockage was.

Can you clear a blocked drain at a Claremont café or shop?

Yes, blocked sinks, toilets and drains. Tell us your trading hours and who will meet us. We don’t pump out grease traps, which is work for a licensed liquid-waste contractor, but we’ll tell you if the trap looks like the reason the drain is backing up.

Who pays if the blockage is in the sewer main?

Blockages in your property plumbing are the owner’s responsibility. If it’s in Water Corporation’s main, normally outside the property, Water Corporation clears it. If we find it there, we call them in.

Western suburbs · Blocked drains, Claremont to Mosman Park

Blocked drains in Claremont, Cottesloe, Swanbourne and Mosman Park

By the early 1900s nearly every street in Claremont had been cut into lots, Peppermint Grove’s blocks had gone on sale in 1891, and Swanbourne still has rows of Federation-era homes, many of them renovated. Add more than a century of big trees and later infill, and the drains here are a patchwork: in 2021 only 39% of Claremont’s occupied homes were separate houses, with the rest split between townhouses, villas and apartments. Even the treated wastewater has a local address, leaving through an ocean outlet off Swanbourne Beach.

The short answer

McDermott Plumbing clears blocked drains, toilets and sinks in Claremont, Swanbourne, Mount Claremont, Karrakatta, Cottesloe, Peppermint Grove and Mosman Park. Call (08) 6187 3999 or text 0406 882 648. This is one of our longest runs from Ellenbrook, so we won’t promise a time. Ring and we’ll tell you honestly when we can be there. Mosman Park is as far as we go, and we don’t work south of the river. We clear with a drain machine or the hydro jetter, and use a CCTV drain camera when a line keeps blocking. If sewage is overflowing from Water Corporation’s main or onto the street, call Water Corporation on 13 13 75 as well.

Claremont, Swanbourne, Mount Claremont and Karrakatta

Claremont’s railway station opened at Butler’s Swamp, the wetland now called Lake Claremont, and land speculators cut the surrounding estates into blocks of many sizes. At the 2021 Census 34.6% of its occupied homes were flats or apartments and 26.1% were townhouses, villas or semi-detached, so a lot of Claremont drains are shared between several homes before they reach the sewer.

Swanbourne mixes older Federation-style homes, many being renovated, with newer estates built on the old Swanbourne Senior High, Swanbourne Primary and Lakeway Drive-In sites. Mount Claremont has four estates, from Old Mount Claremont’s 1940s and ’50s houses near the golf course to the townhouses of St Peters Square and the newer Zamia Gardens. Karrakatta is mostly cemetery and Irwin Barracks, with few homes. The upshot is old drains and new ones side by side, sometimes on the same block.

Cottesloe, Peppermint Grove and Mosman Park

Cottesloe’s homes tend to stay in the same hands: at the 2021 Census 44.8% were owned outright, against 29.2% across WA. A long-held house often still has its original drain under a garden that has had decades to grow. Apartments are part of the mix too, at 18.6% of homes, and a newer planning scheme allows five storeys along Marine Terrace.

Peppermint Grove was thickly wooded with tuart, jarrah, red gum and banksia when it was settled, and it’s named for the Swan River peppermint trees that still line many of its streets. Mosman Park was one of Perth’s industrial centres until the 1970s, but almost all of it is now residential, and 23.9% of its homes were flats or apartments in 2021. Mature trees and old property drains are the usual pairing here.

What blocks drains from Claremont to Mosman Park

Tree roots in older house drains, especially under peppermints and other big street and garden trees. Water Corporation says homes more than 15 years old are less likely to have PVC sewer pipe, and that a hairline crack is all a root needs.
Joins where a renovated Federation or inter-war home’s new bathroom or kitchen meets the original drain.
Shared stacks and lines in apartment, villa and townhouse blocks in Claremont, Cottesloe and Mosman Park. Water Corporation says one 100 mm junction can serve up to five home units.
Beach sand in outdoor gullies and courtyard drains along the Cottesloe and Swanbourne coast.
Fat and wipes. Water Corporation says fats, oils and grease cause 30% of its wastewater blockages, and that wipes don’t break down like toilet paper.

Blocked sink in Claremont?

In a Claremont or Mosman Park apartment, a slow kitchen sink can be your own trap or the shared stack, so ask the neighbours and let the strata manager know if theirs are slow too. In an older Cottesloe or Peppermint Grove kitchen that has been updated, the new sink often drains into an older waste near the outside wall, and that’s where grease builds up. At a café or shop along Stirling Highway, it’s usually grease and scraps in the trap. We clear the sink and the line, but pumping out a grease trap is a licensed liquid-waste contractor’s job. At home, start with the safe checks in our blocked kitchen sink guide, and leave the caustic cleaner on the shelf. If the toilet or the gully outside backs up too, stop using water and call.

How we clear it

These suburbs are at the far end of our western-suburbs run, so tell us when you ring if anything is overflowing and we’ll be honest about timing. We clear from the inspection shaft, gully or nearest sensible access point, with a drain machine for a simple choke and the hydro jetter for roots, grease and sand. If a drain keeps blocking, the CCTV drain camera shows what’s in the line and roughly where, so you can decide whether a section is worth repairing. Jetting won’t mend a broken pipe, and we’ll say so if that’s what we find.

If the blockage turns out to be in Water Corporation’s main, normally outside the property, it’s theirs to clear and we report it. Blockages within the property plumbing are the owner’s responsibility.

Suburbs we cover here: Claremont, Swanbourne, Mount Claremont, Karrakatta, Cottesloe, Peppermint Grove and Mosman Park.

Common questions

Is Mosman Park inside your area?: Yes. It’s the southern edge of our western-suburbs run, and we don’t go past it or south of the river. It’s a long drive from Ellenbrook, so ring and we’ll tell you honestly when we can get there.
The drains in our Peppermint Grove house keep blocking. Could it be the trees?: Quite possibly. Roots from established trees find their way into older drains through cracks and joints. We clear them with the hydro jetter, and a drain camera shows where they’re getting in, so you can decide what to do about that section.
A shared drain in our Cottesloe apartment block is blocked. Who organises the plumber?: Usually the strata manager, because shared stacks and drains are generally common property. We take bookings from strata managers and owners, and we’ll be clear about where the blockage was.
Can you clear a blocked drain at a Claremont café or shop?: Yes, blocked sinks, toilets and drains. Tell us your trading hours and who will meet us. We don’t pump out grease traps, which is work for a licensed liquid-waste contractor, but we’ll tell you if the trap looks like the reason the drain is backing up.
Who pays if the blockage is in the sewer main?: Blockages in your property plumbing are the owner’s responsibility. If it’s in Water Corporation’s main, normally outside the property, Water Corporation clears it. If we find it there, we call them in.

Nearby

Blocked drain and plumber pages for the areas next to this one.

How we clear drains here.

Official sources

Last updated 19 October 2026. General information only. Every property is different, so call us to talk about yours.

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