Can you build over a stormwater main or easement in Hobart?

Many Hobart blocks have a council stormwater pipe running through them, often along the back or side boundary, sometimes in an easement and sometimes not. Before you build an extension, garage, granny flat, deck or pool near one, you need to know whether council consent is required and what the council will want to see.

Building near stormwater in Hobart: quick facts

The trigger

On a council stormwater easement, or within 1 m of a council pipe

The law

Urban Drainage Act 2013 s13; Building Act 2016 ss73–74

Hobart policy

Stormwater Management Policy, 27 May 2024, cl. 28–31

Pools

Consent if over 9 m² or deeper than 300 mm

Conditions

Can bind future owners

Our fee

Fixed quote per job, within 1–2 business hours

Can you build over a stormwater main or easement in Hobart?

You can build over or near a council stormwater main in Hobart only with the council's written consent, and the council can refuse. Under section 13 of the Urban Drainage Act 2013, nobody may build a prescribed structure, or place or remove fill, on a council stormwater easement, within 1 m laterally of the outer edge of the public stormwater system, or above or below that area, without the general manager's consent.

The City of Hobart's Stormwater Management Policy for Development (27 May 2024) repeats this at clause 28: consent from the CEO, who is the council's general manager, under section 13 and sections 73 and 74 of the Building Act 2016, for work within 1 m of the public stormwater system or any other distance set under section 13.

Councils, not TasWater, own and run public stormwater systems under the Urban Drainage Act 2013. A drainage system wholly within one property is private.

What needs consent, and what's exempt?

Since 24 March 2026, every structure needs consent except a short list in the Urban Drainage (General) Regulations 2026. The exemptions are small, light structures that are easy to remove:

Urban Drainage (General) Regulations 2026, regulation 4. Builder's site sheds, some masts and public walkways are also exempt. Any structure within 1 m of a clearly identifiable access point, such as a pit or manhole, needs consent even if it would otherwise be exempt.

How do you know if there's a council pipe or easement on your block?

Start with your title: easements on it are shown on the title plan, often marked as drainage or pipeline easements. Then ask the council, which must keep maps of its public stormwater system under section 12 of the Act. Not every council pipe sits in an easement, and the 1 m rule applies to the pipe wherever it runs.

• Title and plan: the easement's width, position and who it benefits.
• Council stormwater maps: the approximate route of the main, its size and pits.
• On site: pits and grates usually mark the line. A survey of the pipe's position and depth is often needed, because mapped routes can be approximate.

What does the City of Hobart consider before giving consent?

The City of Hobart weighs the risk to its pipe against what you want to build. Clause 29 of the policy lists five matters:

1. Damage to the pipe

   The risk of damaging council infrastructure during construction and over the life of the development.

2. Impacts on your building

   Long-term effects of the stormwater system on the development, and the council's liability for them.

3. Access

   Whether council can still reach the pipe to operate, maintain, renew, replace or upgrade it, in planned work and emergencies, without undue cost to ratepayers.

4. Flood risk

   Public safety and risk to property if a storm exceeds the pipe's capacity and water flows overland.

5. Waterways

   Ecological value, bank stability and natural meandering of open waterways.

Under clause 30, consent can carry ongoing conditions and indemnities, such as removing and reinstating the work at the owner's cost if council needs to. Under section 13(10) of the Act, those conditions bind later owners too. Ask the council how to apply; it may be handled alongside your planning or plumbing application.

What should a consent application include?

A consent application must be made the way the general manager decides and include the plans and information the council asks for (section 13(7)). In practice, the council needs enough to see that the pipe stays safe and reachable. An engineer's package for building near a main usually covers:

• The pipe located and surveyed: alignment, depth, diameter and material
• A site plan with clear offsets from the building to the pipe and the easement
• Footings designed to keep loads off the pipe, usually piers taken below the pipe's level, or beams that bridge over it
• How the pipe is protected during construction: excavation limits, machinery and stockpiles
• How council can still get to the pipe, and how the structure would come out if it had to
• A Form 35 for the design, for the building surveyor

Can you build a pool over or near a stormwater main?

A pool on a council stormwater easement or within 1 m of a council pipe needs consent if it can hold more than 9 m² of water surface or more than 300 mm of water. That covers almost every inground pool, and many above-ground pools too. Excavation for a pool can also undermine a pipe that sits just outside the 1 m line, so the design checks the pipe whatever the distance. Our guide to putting a pool on a sloping block covers the rest of the pool rules.

What happens if you build without consent?

Building on an easement or within 1 m of a council pipe without consent is an offence, with a fine of up to 100 penalty units. The council can also serve a notice requiring the work to be demolished, removed or fixed and the system restored, usually within 28 days. If the notice isn't followed, the council can do the work itself and recover the cost.

This matters when you buy. A garage or extension built over a main without consent can come with a removal risk. A pre-purchase structural inspection can note structures close to pits and easements so your conveyancer can ask the vendor for the consent.

Do Clarence, Glenorchy and other councils have the same rule?

Yes. The Urban Drainage Act 2013 applies to every council's public stormwater system, so the consent requirement applies in Clarence, Glenorchy, Kingborough, Brighton, Sorell and the other Greater Hobart councils. Each council sets its own application form, fees and technical requirements, and some publish their own policies. Check with your council before you design.

When should you call a structural engineer about a stormwater easement?

• Your plans put a building, deck, pool or wall on an easement or within about 2 m of a council pipe
• Council has asked for footing details, offsets or a consent package
• You need footings that bridge or go below a pipe
• The project adds roof or paving and needs on-site detention or a new connection
• You're buying a house with a structure over a pit or easement