Stormwater Drainage Design Sydney — Fast, Council-Ready Plans

RI ENG PTY LTD provides stormwater drainage design in Sydney for houses, townhouses, duplexes and granny flats. Designs comply with AS/NZS 3500.3 and local council standards. Turnaround is 2–5 business days.

Most Sydney homeowners only think about drainage when the certifier asks for it. By then, the design is holding up the whole build. At RI ENG PTY LTD, we turn stormwater drainage plans around quickly, and we draw them to the standard your council actually checks against.

What Stormwater Drainage Design Covers in Sydney

Stormwater drainage design is not just a drawing — it is an engineered plan that controls how rainwater leaves your property.

Every Sydney property handles rain differently. Soil type, slope, lot size and surrounding infrastructure all affect the design.

At RI ENG PTY LTD, we analyse each site individually. We do not use templates. Your design reflects the actual conditions on your land.

A typical stormwater drainage design includes: surface drainage grades, pipe sizes and layouts, pit locations, connection to the street drainage network, and overflow paths.

We cover houses, townhouses, duplexes, attached dwellings and granny flats across the Greater Sydney region.

Sydney Council Requirements for Stormwater Drainage

Sydney councils are strict about stormwater. Every new home, extension or secondary dwelling needs an approved drainage plan before construction begins.

The design must meet AS/NZS 3500.3 — the Australian plumbing and drainage standard. It must also match the local council’s specific requirements.

Councils across Greater Sydney — including Blacktown, Parramatta, Canterbury-Bankstown, Liverpool and Northern Beaches — each have their own technical specifications.

We know these requirements well. We design to each council’s standard so your application does not come back with corrections.

Our reports include hydraulic calculations, drainage plans and supporting documentation — everything your certifier needs in one package.

Why Drainage Design Matters Before You Build

Skipping proper drainage design causes problems that are expensive to fix after construction.

Water that pools near foundations damages concrete slabs over time. Poorly graded yards direct water toward walls instead of away from them.

Neighbours have legal protection against water runoff crossing boundaries. If your drainage is wrong, they can lodge a complaint.

Getting the drainage plan right before you build saves you from rework, disputes and certifier rejections.

RI ENG PTY LTD delivers clear, buildable drainage plans that your builder and certifier can use immediately.

Common Questions About Stormwater Drainage Design in Sydney

Q: Do I need a drainage design for a granny flat in Sydney?

A: Yes. Sydney councils require a compliant stormwater drainage design for granny flats. RI ENG PTY LTD handles these designs with a quick turnaround.

Q: How long does stormwater drainage design take in Sydney?

A: Most designs are ready within 2–5 business days after we receive your site plan and survey.

Q: What documents do I need to provide?

A: You need a site survey or site plan, your lot dimensions, and the council’s drainage connection point if known. We guide you through the rest.

Q: Can you design drainage for a knock-down rebuild?

A: Yes. We regularly design stormwater drainage for knock-down rebuilds across Sydney. The process is the same as for a new build.

Q: Do you cover all Sydney councils?

A: Yes. We cover all Greater Sydney local government areas and design to each council’s specific stormwater requirements.

Ready to Start Your Sydney Stormwater Drainage Design?

RI ENG PTY LTD designs stormwater drainage for houses, duplexes, townhouses and granny flats across Greater Sydney. We know what each council wants to see, and we draw it that way the first time.

Send us your site address, survey and project type. We will confirm the scope, give you a fixed fee and tell you exactly when your plans will land in your inbox.

🌐  riengineering.com.au

📞  +61 0451 452 932

📧  riengineering2155@gmail.com