Maraylya 2765 · The Hills Shire
Home Extensions in Maraylya: Building Near a Creek on Acreage
Five hectares, and the new wing still has to stay back from a trickle of water.
Maraylya's acreage is cut through by gullies feeding Cattai Creek. Some run a few weeks a year. The law treats plenty of them as rivers anyway, and that decides where an extension can go long before anyone argues about floor plans.
Short answer
Can I extend my Maraylya acreage home close to a creek?
Sometimes, but work within 40 metres of a watercourse bank counts as waterfront land under the Water Management Act 2000, and building there usually needs a controlled activity approval from the Natural Resources Access Regulator. Most owners avoid it by siting the addition outside the riparian zone. The Hills Shire assesses DAs in 11 to 15 weeks, and brick veneer additions run about $1,925 to $2,080 per m².
Written and reviewed by Oliver Alameri
Licensed builder, NSW Contractor Licence 487805C · Founder, Buildana
Fact-checked
Is that gully a watercourse?
Probably, if it shows on the topographic map as a blue line. Dry most of the year doesn't matter. Under the Water Management Act, the bed of a river or creek plus the land within 40 metres of its highest bank is waterfront land.
Streams are ranked by order. A first-order stream is the top of the catchment, the smallest gully. Where two meet you get second order, and so on. The regulator's guidelines pair each order with a vegetated riparian zone, from around 10 metres each side for the smallest to 40 metres for the bigger creeks.
So the first job on any Maraylya extension is a site survey that plots every drainage line and its top of bank. Guessing from the kitchen window costs people a redesign.
- Blue lines on the topographic map, even dry ones
- Top of bank surveyed, not estimated
- Stream order, which sets the riparian zone width
- Existing vegetation along the banks
The cheapest riparian approval is the one you never need, because the wing sits somewhere else.
When you can't avoid waterfront land
Sometimes the house was built close to the gully decades ago and any sensible addition lands inside the 40 metres. Then the DA becomes integrated development. The application goes from council to the regulator, which issues general terms of approval, and those conditions end up in your consent.
Expect conditions on sediment fencing during the build, where stockpiles can sit, stormwater dispersal away from the bank, and sometimes replanting native vegetation to rebuild the corridor. Standard stuff for a regulator, honestly. It just has to be planned for, and it adds weeks to assessment.
Not sure where the creek rules start?
Send me your Maraylya lot and roughly where you'd like to extend. I'll map the drainage lines against it and tell you whether the regulator is likely to be involved.
0476 300 300Bushfire, rock and the long service runs
Most of Maraylya is bushfire prone, so the new work is built to the site's BAL and the report often shapes window sizes on the bush side. Timber decks near the gully are usually the first thing the consultant flags.
Ground on the acreage belt is typically Hawkesbury sandstone. Footings love it. Excavation doesn't. A single-level wing that follows the fall is usually cheaper than cutting a flat pad.
And on a big holding, the house can be a long way from the septic system, the power pole and the water tank. Extra bedrooms may mean a bigger wastewater system; extra bathrooms mean longer pipe runs.
Cost and approval in The Hills
For a mid-sized wing, say 75 to 125 square metres in brick veneer on one level, the Sydney handbook rate from Rawlinsons is $1,835 to $1,980 a square metre. Add this area's 1.05 loading and it's roughly $1,925 to $2,080, before kitchens, bathrooms, bushfire upgrades or wastewater work.
Rural extensions rarely fit complying development once bushfire and riparian mapping are in play, so plan on a DA. The Hills Shire's assessment of a single dwelling generally takes 11 to 15 weeks; integrated referrals push that out.
Before you sketch the new wing
What I'd confirm on any Maraylya property first.
- 01
Where is every mapped watercourse, and its top of bank?
- 02
What stream order are they?
- 03
Can the addition sit fully outside 40 metres?
- 04
What BAL applies to the proposed footprint?
- 05
Will the septic or wastewater system need upgrading?
- 06
How far are power, water and sewer from the new wing?
Extending on Maraylya acreage
What is waterfront land?
The bed of a river, creek or lake and the land within 40 metres of its highest bank, as defined in the Water Management Act 2000.
Who issues a controlled activity approval?
The Natural Resources Access Regulator. When the work is part of a DA, council refers it and the regulator provides general terms of approval.
Does a dry gully count as a creek?
Often, yes. Mapped watercourses count whether or not water is flowing, so a survey of the drainage lines should come before design.
Can I use complying development for a rural extension?
Rarely in Maraylya. Bushfire, riparian and rural zoning constraints usually push the project to a development application with The Hills Shire.
Sources and references
Costs are from the Rawlinsons handbook with the local cost index applied; rules and timeframes are checked against the sources below.
- The Hills Shire Council
- Rawlinsons Australian Construction Handbook, Rawlhouse Publishing
- Environmental Planning and Assessment Act 1979 (NSW)
- State Environmental Planning Policy (Exempt and Complying Development Codes) 2008
- Building on bush fire prone land, NSW RFS
- Water Management Act 2000 (NSW)
- Biodiversity Conservation Act 2016 (NSW)
Room to grow, sited properly.
A Maraylya extension placed where the land, the creek and the council all agree.