Stormwater pit installation in Melbourne follows the drawings and specification of whoever will own the pit. That’s the council, Melbourne Water or the state road authority. They set the concrete grade, the steel, the lid and the finish.
This guide covers what those published standards ask for and how stormwater pit installation works when the pit is built in situ. Our part is the formwork, reinforcement and pour. We build to your engineer’s drawings.
Related reading
- Our service: Concrete Pits and Chambers
- Pits in the west: Concrete Pits in Truganina
- Wider drainage works: Drainage Structures in Wyndham
Stormwater Pit Installation: Who Sets the Rules
Each owner publishes its own standard for stormwater pit installation, and the numbers differ. These examples come straight from published documents.
25 MPa
Council concrete strength
Merri-bek’s pit standard, unless the drawing says otherwise
Over 1 m
Step irons required
Wyndham and Merri-bek both set this depth
Over 2 m
F72 fabric in the walls
Merri-bek’s junction pit, placed centrally
Within 5 mm
Cover level tolerance
Melbourne Water manholes, against the drawing
| Owner | What the published standard asks for |
|---|---|
| Council (Merri-bek junction pit) | 25 MPa concrete. Pits cast monolithically, with render only to repair defects. Minimum inside size 900 x 600 mm. Class B lid as standard, Class D in road pavement. |
| Melbourne Water (manholes and concrete structures) | N25 concrete unless the drawings say otherwise. Outside formwork on the shaft, with no slip forming. Class 2 finish or better. Access step irons cast in situ. |
| State road standard (VicRoads Section 705, Wyndham copy) | Cast-in-place pits built to Sections 610 and 611, with no fibre reinforced concrete. VR330/32 minimum grade for steel-reinforced pits. Lid frame level within 10 mm. |
Standards get updated. Always check the current drawing and specification for your site and your authority.
That’s why we ask for the drawings and the authority’s name first on every stormwater pit installation. We build to what your drawing says.
“They completed the work on time, kept the site clean, and were always happy to answer questions and offer helpful suggestions.”
★★★★★ NO Shops, customer review of Cinerari Contracting
What the Drawing Should Show Before the Pour
A complete drawing makes for a smoother build and a smoother inspection. Here’s what to settle early for stormwater pit installation, and what the published standards rule out.
Should be on the drawing
- Pit size and depth
- Concrete grade
- Reinforcement size and position
- Lid or grate class and frame level
- Step irons, if the pit is deeper than 1 m
- Pipe opening positions and levels
Ruled out by the published standards
- Slip forming a manhole shaft (Melbourne Water)
- Bagged mortar on manhole walls (Melbourne Water)
- A finish below Class 2, which Melbourne Water can direct to be rebuilt at the contractor’s cost
- Fibre reinforced concrete in a cast-in-place pit (state road standard)
- Breaking out holes made on site, rather than cutting or coring them (state road standard)
Got pit drawings and need a build price? Send them over and we’ll take it from there.
Related service
Concrete Pits and Chambers
In-situ concrete pits, drainage pits and chambers, service and utility pits, valve pits and access chambers, built to the engineering drawings.
Excavation and Base Preparation for Stormwater Pit Installation
Every pit starts in the ground. We excavate to the depth and size on the drawing and remove unsuitable material. Where the drawing calls for it, we prepare the sub-base and add blinding.
Wyndham’s specification says excavation goes to the depth on the drawings, or deeper if that’s what it takes to reach a satisfactory foundation. Deep holes carry real risk. WorkSafe Victoria’s excavation code gives practical guidance on planning the work and reducing the risk of ground collapse.
We keep the ground stable and the access safe through the works. The same goes for the site setup around the pit.
Formwork and Reinforcement for Stormwater Pit Installation
Formwork gives the pit its shape, so it has to hold. Wyndham’s formwork section asks for forms that are rigid, watertight, braced and tied together. We brace our formwork and temporary works to stop movement during the pour.
The same section asks for 20 mm by 20 mm chamfers on corners. It wants tie wire and debris cleared out of the forms before concrete goes in. Ties can’t run through to the finished surface.
Reinforcement goes in strictly to the drawing. Merri-bek asks for F72 fabric centred in the walls of pits over 2 m deep. Section 610 also asks for bar supports that hold the steel still and keep the specified cover.
We coordinate pipe openings and services at this stage so they sit where the drawing puts them. Where a site needs weep holes, Melbourne Water’s spec asks for the hole formwork to be set before the pour, at least 38 mm across. Our formwork and reinforced concrete crews handle this work.
Pour, Finish and Cure
Pours are supervised, with controlled placement. We test the concrete where the project specifies it.
Merri-bek asks for pits to be cast monolithically, with render used only to repair defects. Melbourne Water asks for a Class 2 finish or better on manhole walls. Under the state road standard, Class 2 means uniform colour and texture, no major surface defects, and formwork that flexes no more than 3 mm between supports.
Curing protects that finish. In the Section 610 table, VR330/32 concrete in exposure classes A and B1 with general purpose cement needs 7 days of curing at an average air temperature of 10 to 17°C. Above 17°C it’s 6 days. Your drawing and mix set the real figure.
“The team was punctual, professional, and very knowledgeable, making the whole process smooth and stress-free.”
★★★★★ nomar group, customer review of Cinerari Contracting
Lids, Step Irons and Pipe Openings
Lids and grates follow AS 3996, and the class depends on where the pit sits. Merri-bek lists a Class B lid as standard and Class D for pits in road pavement. The drawing names the class for your pit.
Step irons go in pits deeper than 1 m. Melbourne Water wants access step irons in manholes cast in situ. The cover frame then has to land on level, within 5 mm for Melbourne Water manholes and within 10 mm under the state road standard.
The state road standard also says holes made on site are cut or cored. Breaking them out isn’t permitted. For related civil work, see our guide to concrete culverts and VicRoads specs.
Safety in Deep Pits and Chambers
Pits mean deep excavations, vertical formwork and confined working spaces. On our stormwater pit installation jobs, fall protection, exclusion zones and confined-space controls are in place at every stage.
WorkSafe Victoria publishes compliance codes for excavation and for confined spaces. Its excavation page says the codes aren’t mandatory. It also says following one means you’re deemed to comply with the matching duty.
What Changes the Price of Stormwater Pit Installation
We don’t quote stormwater pit installation from a rule of thumb. The price comes from your drawings. These things move it most:
- Pit size and depth
- Ground conditions, and whether unsuitable material has to be removed
- The amount of reinforcement on the drawing
- The number and position of pipe openings
- Lid and frame requirements
- Testing and inspection hold points your authority asks for
- Site access
Send the drawings and the authority’s name. We review scope, risks and access before we price the job. For the wider drainage picture, see stormwater pits in Melbourne and civil drainage.
How We Work With You
1
Talk to us about your scope
Send the drawings, pit dimensions and authority requirements for review.
2
Confirm plan and pricing
We assess scope, risks and access, then give you clear pricing.
3
Accurate delivery
Works move through inspection stages to keep the pit compliant.
4
Clean handover
Formwork is stripped safely, the pit is complete and the site is left clean and tidy.
Get a Stormwater Pit Installation Quote for Your Melbourne Project
Cinerari Contracting builds in-situ concrete pits and chambers for civil, industrial, utility and commercial projects across Victoria. Send your drawings and we’ll tell you what it takes.
Who Decides the Specification for Stormwater Pit Installation?
The authority that will own the pit. That’s the council, Melbourne Water or the state road authority. Their drawings and specs set the concrete, steel, lid and finish, and we build to the drawings you give us.
How Much Does Stormwater Pit Installation Cost in Melbourne?
It depends on pit size and depth, the ground, the steel on the drawing, the number of pipe openings, the lid and frame, and the testing your authority wants. We don’t price from a rule of thumb. Send your drawings and we’ll quote the job.
Should a Pit Be Cast in Place or Precast?
The drawing decides. Wyndham’s spec allows both, with conditions. Cast-in-place pits are built to Sections 610 and 611 and can’t use fibre reinforced concrete. Melbourne Water also lets contractors use precast manholes if every requirement is met. We build in-situ pits.
What Lid Class Does a Stormwater Pit Need?
The drawing names it, under AS 3996. In Merri-bek’s junction pit standard, the lid is Class B as standard and Class D in road pavement areas. Other councils set their own.
When Does a Pit Need Step Irons?
Wyndham’s spec and Merri-bek’s standard both call for step irons in pits deeper than 1 m. Melbourne Water wants access step irons in its manholes cast in situ.
Can Cinerari Handle Stormwater Pit Installation to Melbourne Water and Council Standards?
Yes. We build pits to VicRoads, Melbourne Water or project-specific authority standards where required, strictly to the engineering drawings. Inspection hold points and documentation follow your authority’s requirements.
More Concrete and Civil Guides
About the author
Cinerari Contracting is a Melbourne civil and reinforced concrete subcontractor. We build driveways, slabs, footings, formwork, retaining walls, pits and drainage for builders, developers and homeowners across Melbourne and regional Victoria.
Phone: 0400 692 550 · Email: hello@cineraricontracting.com
Sources
- Wyndham City Council, Technical Specification Section 705, Drainage Pits and Covers (November 2021)
- Wyndham City Council, Technical Specification Section 614, Formwork (November 2021)
- Wyndham City Council, Technical Specification Section 610, Structural Concrete (November 2021)
- Merri-bek City Council, Junction Pit Technical Note A140.01 (October 2022)
- Melbourne Water, Manholes, concrete inlet and outlet structures
- WorkSafe Victoria, Compliance code: Excavation
- WorkSafe Victoria, Compliance code: Confined spaces
Information in the concreting industry changes frequently. Linked content may change or become outdated. Please always contact us for help with your important building decisions.
