Black Forest: Greenhill Road Works Straining Older Sewer Lines
City of Unley · Council intelligence · Last updated April 2026
“NOTICE OF MOTION FROM COUNCILLOR M BRONIECKI RE: WALKING AND CYCLING INFRASTRUCTURE ON GREENHILL ROAD”
Full Council, 23 March 2026
Greenhill Road runs along the northern edge of Black Forest — any infrastructure works along there means digging, and digging near older suburbs like this tends to disturb the ground around ageing sewer and stormwater laterals. If you've had slow drains or soft patches in the yard, keep an eye on it while this stuff is being scoped.
“Administration work with staff from the City of Adelaide and the City of Burnside to investigate the provision of improved walking and cycling infrastructure along the southern boundary of the Adelaide Park Lands fronting Greenhill Road from Anzac Highway to Fullarton Road.”
Full Council, 23 March 2026
That's the full stretch from Anzac Highway to Fullarton Road under investigation — Black Forest sits right in that zone. When three councils are coordinating ground-up works along a shared corridor, access to your street or junction can get complicated fast. If you need a plumber in a hurry during this period, it pays to use someone who knows the local access points.
Black Forest sits right on the edge of Greenhill Road, and the City of Unley is looking hard at what happens along that corridor — walking and cycling upgrades, kerb-to-kerb changes, the lot. That kind of work doesn't just affect traffic. It puts pressure on older stormwater and sewer infrastructure running under streets in this pocket, and Black Forest has plenty of that — mostly fibro and clay pipes under homes built in the 50s, 60s and 70s. Worth knowing if you've got a slow drain or a damp patch that's been getting worse.
Black Forest's plumbing problems are almost always about age and soil. The housing stock is 50+ years old, the clay soil doesn't drain, and the original pipes—clay, fibro, sometimes corroded copper—are working harder now than they ever were designed to. If you're seeing slow drains, damp patches, or water pooling in the garden, the issue is usually below ground. Get a camera through the line before you start pulling things apart. The Greenhill Road corridor work has made things worse in the short term. Council's digging up streets, water mains are being pressured, and older sewer systems are backing up. If something's started acting up in the last few months, it might not be coincidence. Call early, don't wait until you've got sewage coming back inside.
- Cracked or root-invaded clay sewer pipes on blocks built pre-1975—Black Forest is full of homes where the main line is original clay and the trees have had 50+ years to work their way in
- Stormwater backup on the older flat allotments near Black Forest reserve—clay soil, poor drainage gradient, and gutters on 70s-era homes that can't cope with even moderate rain
- Hot water unit failures in original 60s and 70s brick veneer homes—gas storage units well past their use-by date, often still the original install
- Leaking or failed flexi hoses under kitchen and bathroom sinks in homes with original cabinetry—cheap braided hoses from the 70s that haven't been touched
- Spouting and downpipe blockages from established trees backing up into slab edge—big trees planted when houses went up now dropping leaf litter faster than gutters can drain
- Damp patches on internal walls and foundation cracks linked to poor external stormwater drainage—common on the lower blocks where water pools after rain
- Slow or blocked drains on blocks with shallow pipework and clay soil—Black Forest's soil type and pipe depth mean blockages clear slower than in surrounding areas
- Failed or corroded copper pipes in homes built early 1970s—some of the fibro and early brick veneer stock was plumbed with copper that's now fragmenting
- Septic or shared sewer issues on older blocks not yet converted to mains—a few pockets in Black Forest still on older systems that Council of Unley is slowly integrating