St Marys facts that matter
Most homes are rented
At the 2021 Census, 52.6% of the suburb's occupied homes were rented, against 32.6% across NSW. Only 17.9% were owned outright.
Plenty of attached homes
51.2% were separate houses, 30.0% semis, terraces or townhouses, and 18.5% flats or apartments.
Penrith City Council
Every dwelling ABS counts in St Marys is in the Penrith council area, and Council names the suburb in its flood studies.
Three flood plans and a levee
Penrith has adopted plans for South Creek (April 2020), the St Marys Byrnes Creek catchment (March 2020) and Little Creek (February 2022). The St Marys levee was built to reduce flooding from South Creek.
Renting: whose pipes are they?
Sydney Water is clear that property owners own the wastewater pipes up to and including the point of connection, and the drinking water pipes from where they join its system to the taps. So if you rent, a leak or blockage is something to report to your landlord or agent straight away, in writing, with photos.
If water is pouring out and you can't reach anyone, turn it off at the meter, usually at the front of the property. Our emergency plumber page for Sydney covers what to do next.
Townhouses and strata
NSW strata rules cover townhouses, villas and many duplexes as well as apartments. In most cases the owner of the lot handles fixtures and pipes in internal walls, and the owners corporation handles plumbing in boundary walls and under the floor. Check the strata plan and by-laws, because they decide the details.
If you own a townhouse and act in an emergency, you may be able to recover the cost when the fault was the owners corporation's. Keep photos and the plumber's written explanation.
Heavy rain and the sewer
St Marys falls inside three of Penrith's flood study areas. When stormwater gets into the sewer in heavy rain, the system can overload and overflow onto properties, sometimes inside homes. Sydney Water says the overflow relief gully should work like a safety valve. Its inspectors look for gullies that are damaged or too close to the ground, and for downpipes connected to them.
Whether a lot is below Penrith's flood planning level shows on its section 10.7 planning certificate as a flood notation. Read it before major drainage work or an extension. See blocked drains in Sydney.
What we would do
Renters: report the fault in writing the same day and keep a copy. Owners: if your yard sits low, look at the overflow relief gully. It should be clear, undamaged and sitting above the surrounding ground. If it's buried, cracked or has a downpipe running into it, get a drain specialist to fix it before the next big storm.