Ferntree Gully details that matter
Knox, since 1963
Knox lists Ferntree Gully and Upper Ferntree Gully among its suburbs. The city was formed on 16 November 1963 when it separated from the Shire of Ferntree Gully.
Mostly houses
88.0% of occupied homes in the suburb were separate houses at the 2021 Census. 42.6% were mortgaged and 21.2% rented.
Owner's drains
Knox makes owners responsible for stormwater inside the boundary, household drainage and the connection to Council's drain.
South East Water
Ferntree Gully is on South East Water's supply list, and Knox itself sends sewer pipe questions to South East Water.
What Knox expects from owners
Gutters, downpipes, rainwater tanks and, in most cases, the property stub count as household drainage, which Council doesn't maintain or inspect. A new or altered connection to Council's drain or kerb needs Council approval and is done at your cost. Knox recommends a licensed plumber for internal drainage problems.
Council's drains protect against storms up to a five-year average recurrence interval in residential areas, and Melbourne Water covers the bigger events. Knox's flood work focuses on keeping water out of living areas, not gardens, yards, garages or sheds.
Find your approved point of discharge
Every Knox property has an Approved Point of Discharge, where its stormwater enters the authority's network. Your runoff stays your responsibility until it gets there, even if it crosses a reserve or a neighbour's yard on the way.
Knox's Approved Point of Discharge report shows where that point is, and a separate Flood Information Report draws on Council's flood modelling. Get one before a new drain or an extension goes in. Our stormwater page explains the plumber's side.
Canopy trees since September 2025
Clause 52.37 arrived in every Victorian planning scheme on 15 September 2025. In Knox's residential zones, removing, destroying or lopping a canopy tree over 5 metres tall needs a permit anywhere on a vacant lot, or, with a house on the land, within 6 metres of the narrowest street frontage or 4.5 metres of the rear boundary. Overlays protect other trees, so talk to Knox before a trench goes near one.
South East Water's part
South East Water looks after the sewer up to the inspection opening, which is often near your boundary. The pipes on the house side are yours. If a blockage could be on its side, the plumber needs to refer it to South East Water before jetting, cutting roots or using a camera, or the reimbursement is lost. See blocked drains in Melbourne.
What we would do
Order Knox's point of discharge report before any new drainage work, and keep it with the house papers. It tells a drainage plumber where your stormwater is meant to go. For a blocked sewer, locate the inspection opening so South East Water's side can be ruled in or out early. Then send us the details and the job goes to licence-checked plumbers who specialise in drains.