Retaining Walls in Evatt

A Belconnen suburb from the early seventies

Wikipedia says Evatt is a suburb in the Belconnen district of Canberra, lying between McKellar, Belconnen, Florey, Melba and Spence. It is named after Herbert Vere Evatt, who lived from 1894 to 1965, and was gazetted on 2 November 1972. Streets are named after people associated with parliament and the law. A suburb of this age has houses that are now several decades old, and old retaining walls on sloping blocks are a common repair job in suburbs like it.

Edges and borders

The article says Evatt is bordered by Copland Drive, Owen Dixon Drive, William Webb Drive and Ginninderra Drive, and has three neighbourhood ovals. It lists three primary schools, Evatt Primary, Miles Franklin Primary and St Monica's. If your block backs on an oval or a school fence, a wall at the back is a boundary wall in practice, and ACT Planning's lower limits for walls within 1.5 metres of a boundary will matter.

Glebe Farm and older ground

The education section says the first school in the area used the original Ginninderra Anglican church of St Paul, on land established in 1861 as Glebe Farm, with 81 hectares for the farm that supported the church. The land was a donation from Charles Campbell of Duntroon. We mention it as local history only. It does not tell us anything about the ground under your block, and a builder will need to see it.

Porphyry under almost everything

The geology section says a green-grey dacitic porphyry with large white feldspar crystals lies under almost all of Evatt, including everything north of Moynihan Street. It adds that the Deakin fault cuts the south-west corner near Brebner Street and that there is a patch of calcareous shale right in that corner. Hard intrusive rock can make post holes slow, which is why Yakka Labour tells owners to allow for rock when comparing excavation lines.

Heights, loads and design

Yakka Labour says walls around one metre or higher usually need approval and an engineer's design, and that any wall supporting a driveway, building or pool does too. An Access Canberra factsheet says plans must show the height of the earth cut being retained. ACT Planning says a wall not higher than 1.2 metres does not need a building approval. Compare your height with both and ask a certifier.

Where to start

For a tall wall in segmental or core-filled block, start with our block wall guide. For a wall that is leaning or holding water, read the engineered walls guide.

What is the rock under Evatt?

Wikipedia says a green-grey dacitic porphyry lies under almost all of the suburb. It is general information, not a site assessment.

Do old walls in Evatt need replacing?

We cannot judge a wall from a form. Yakka Labour lists a lean, cracks, seepage and soil washing out as signs, and says a moving tall wall needs an engineer.

Is a wall near an oval or school boundary treated differently?

ACT Planning's development approval page gives lower limits, 0.4 metres, for parts of a wall within 1.5 metres of a side or rear boundary. Check it for your block.