§ RESOURCES / GLOSSARY

Glossary.
The terms estimators actually use.

A working reference for the language of water and sewer infrastructure estimating in Australia. DTC numbers, encasement codes, pipe materials, manhole specifications, authority terminology. If a term you need isn’t here, tell us — we’ll add it.

// JUMP TO

Authorities Standards & Codes Pipe Materials Fittings & Components Sewer-Specific Water-Specific Construction Methods Site Conditions

Authorities

Sydney Water (SW): The water and sewer authority for Greater Sydney. Publishes the Design and Construction Specifications used across NSW for SW assets. Most water and sewer infrastructure estimating in Sydney references Sydney Water specs.
Hunter Water (HW): Water and sewer authority for the Lower Hunter region of NSW (Newcastle and surrounds). Has its own design specifications, similar to but distinct from Sydney Water.
Melbourne Water (MW): Wholesale water and sewer authority for Greater Melbourne. Works alongside retail water businesses (Yarra Valley Water, South East Water, City West Water) in delivering infrastructure.
SA Water (SAW): Water and sewer authority for South Australia, covering Adelaide and regional centres.
Queensland Urban Utilities (QUU): Water and sewer authority for South East Queensland (Brisbane, Ipswich, Lockyer, Scenic Rim, Somerset).
WSAA: Water Services Association of Australia. Publishes national codes and standards used across all Australian water authorities, including the WSAA Sewerage Code, Water Supply Code, and related guidelines.
MRWA: Melbourne Retail Water Agencies — the joint body for Melbourne’s retail water businesses. Publishes shared technical specifications used across the Melbourne metropolitan area.

Standards & Codes

DTC: Design Technical Code — Sydney Water’s standard drawings for water and sewer infrastructure. Each drawing has a DTC number that defines a specific configuration. Estimators reference DTC numbers to know exactly what materials, dimensions, and methods are required for a given component.
DTC 1124: Sydney Water standard for a water main handle bar configuration using DICL pipe with a straight section of 6 metres or less. Always 4 bends (45° down, 45° to flat, 45° up, 45° to original alignment).
DTC 1126: Sydney Water standard for a water main handle bar configuration using MSCL pipe with a straight section greater than 6 metres. Can have 4 or 6 bends depending on depth. MSCL requires welded joints, which adds cost and time compared to DTC 1124.
DTC 2200: Sydney Water standard for a DN1200 sewer manhole. Specifies base thickness, wall thickness, reinforcement, and benching requirements.
DTC 2203: Sydney Water standard for a DN1050 sewer manhole. Smaller than DTC 2200 with different reinforcement requirements.
12U encasement: Plain (unreinforced) concrete encasement specification. Used for sewer pipe protection in lower-load conditions. Less expensive than 12R as no reinforcement cage is required.
12R encasement: Reinforced concrete encasement specification. Used where additional load capacity is required — under roads, in deeper installations, or where ground conditions demand it. Costs more than 12U because of the reinforcement cage and additional construction time.
AS/NZS 3500: Australian and New Zealand standard for plumbing and drainage. Covers water supply, sanitary drainage, and stormwater installations. Referenced widely in residential and commercial water estimating.
Section 73 (NSW): Reference to Section 73 of the NSW Water Management Act — the certificate required by Sydney Water for water and sewer servicing of a new subdivision or development. Section 73 works are the infrastructure required to obtain the certificate.

Pipe Materials

PVC Blue: Polyvinyl chloride pipe coloured blue, used for potable (drinking) water mains. Common in subdivision reticulation. Joined with rubber ring joints (RRJ).
DICL: Ductile Iron Cement Lined pipe. Strong, suitable for higher pressures and larger diameters. Available in flanged and socket configurations. Used in main trunk lines and where pipe strength matters.
MSCL: Mild Steel Cement Lined pipe. Used for very large diameter water mains and high-pressure applications. Joints are welded rather than coupled, which significantly increases installation time and cost compared to DICL.
PE: Polyethylene pipe. Flexible, suitable for trenchless installation and rising mains. Joined by butt-welding or electrofusion. Used heavily in pump station rising mains and underbore applications.
Lilac pipe: Recycled water main — pipe coloured lilac (purple) to distinguish it from potable water (blue). Used in dual-reticulation subdivisions where each lot gets both potable and recycled water connections. Different fittings and tapping bands than blue pipe.
OPVC: Oriented PVC pipe. Stronger than standard PVC, used where higher pressures or larger sizes are required. Sometimes substituted for DICL in design changes.

Fittings & Components

RRJ (Rubber Ring Joint): Pipe joint method using a rubber ring seal. Quick to install. Standard for PVC and many DICL applications.
Flanged joint: Pipe joint using bolted flanges. More expensive and time-consuming than RRJ but allows for valves, fittings, and easier disassembly. Required in puddle flange arrangements and at major junctions.
Stop valve: Inline valve to isolate a section of water main. For pipes up to and including DN200, the standard arrangement uses a PVC pipe with a socket-socket valve, plastic shroud, and stop-and-cover at surface level.
Puddle flange: The valve arrangement used for water mains DN250 and above. Replaces the simpler stop valve setup with flanged DICL pipe sections, a flanged-flanged stop valve, and a reinforced concrete thrust block. Total length around 6 metres. Significantly more expensive than a stop valve.
Hydrant: Connection point for fire-fighting water supply. Installed at regular intervals along water mains, particularly in subdivisions.
Flushing bend: Termination fitting at the end of a water main allowing the line to be flushed during commissioning. Common in subdivision reticulation at dead-ends.
Property connection: The water service from the main to an individual lot. Each lot in a subdivision gets a property connection — or two, if the subdivision has both potable and recycled water.
Tapping band: Fitting used to tap a smaller service line off a larger water main. Different bands for different pipe types (blue PVC, lilac recycled).
Manhole: Vertical access chamber for sewer mains, allowing inspection, cleaning, and connection. Sized by DTC number (DN1050 = DTC 2203, DN1200 = DTC 2200). Specs cover base thickness, wall thickness, reinforcement, and internal benching.
PCS (Property Connection Sewer): Term sometimes used for the sewer connection from main to lot. Includes the junction off the main and the lateral run to the property boundary.
Junction: A branch fitting allowing a property connection or smaller line to tee off the main sewer. Often pre-installed during main laying or cut in afterwards.

Sewer-Specific Terms

FIFM: Flow Monitoring — temporary instrumentation to measure sewer flow during connection or diversion works. Required by some authorities for live sewer works to confirm bypass capacity and report flow rates.
Sewer bypass: Temporary diversion of live sewer flow during construction works. Typically uses pumps and temporary pipework to maintain service while the main line is being modified. Cost driven by flow rate, duration, and number of bypass connections.
Benching: Concrete shaping inside a manhole base to direct sewer flow. Also refers to a stable trench profile where excavation walls are battered back rather than vertical, used as an alternative to shoring in suitable ground.
Shoring: Temporary support for trench walls during deep excavation. Required where ground conditions don’t allow benching, where there’s insufficient room to batter the trench, or where adjacent infrastructure must be protected. Methods include trench boxes, sheet piles, and proprietary shoring systems.
Concrete encasement: Concrete surround poured around a sewer pipe for protection and load distribution. Specified as 12U (plain/unreinforced) or 12R (reinforced). Required under roads, at deep installations, and at handle bar crossings.
Hydrostatic testing: Pressure-testing of sewer pipework with water to confirm joint integrity and pipe condition. Standard part of sewer commissioning before a main is brought into service.
CCTV inspection: Closed-circuit television survey of completed sewer mains to confirm condition, alignment, and absence of defects. Standard authority requirement for new infrastructure.
Underbore: Trenchless installation method — the pipe is pulled or pushed under an obstruction (road, river, building) without open excavation. Two main methods: HDD (horizontal directional drilling) and static bore. Cost driven by ground conditions, casing requirements, and pit construction.

Water-Specific Terms

Lead-in main: An extension of the water network from existing infrastructure to a new development or area. Typically required when existing mains can’t meet new demand. Routes can run through greenfield, farmland, or private property — the route drives much of the cost.
Reticulation: The internal water (or sewer) network within a subdivision — the distribution mains and connections that feed individual lots, as opposed to the trunk infrastructure that feeds the subdivision itself.
Handle bar: A water main configuration where the pipe goes down, runs flat under an obstruction (typically a stormwater pipe), then comes back up to original alignment. Shaped like a bicycle handle when viewed in profile. Specified as DTC 1124 (DICL pipe, ≤6m straight section) or DTC 1126 (MSCL pipe, >6m straight section, can have 4 or 6 bends).
Disuse and divert: The process of taking an existing main out of service and building a replacement on a different alignment. Disuse can mean cap-off and abandon-in-place, removal, or grout-filling depending on authority requirements. Divert is the new build.
Recycled water: Treated wastewater used for non-potable applications: toilet flushing, clothes washing, garden irrigation. In subdivisions with recycled reticulation, every lot receives both a potable and a recycled connection. Recycled mains are lilac-coloured and use distinct fittings.
Shared run: An installation where potable and recycled water mains are laid in the same trench. Saves excavation cost but requires careful separation, distinct fittings, and clear marking to avoid cross-connection.

Construction Methods

Open-cut / open-trench: Standard excavation method — dig a trench, lay the pipe, backfill. Cheapest method when access allows.
HDD (Horizontal Directional Drilling): Trenchless method using a steerable drill head. Suitable for variable-depth bores, longer runs, and curved alignments. Common for water mains under busy roads or environmentally sensitive areas.
Static bore: Trenchless method using a hydraulic ram to push a pipe (often within a steel casing) under an obstruction. Used for shorter, straighter crossings.
Casing pipe: An outer steel pipe installed by underbore, into which the carrier pipe (water or sewer) is later inserted. Used where ground conditions or installation method require it.
Free bore: Underbore where the carrier pipe is installed directly without an outer casing.
Butt welding: Joining method for PE pipe — pipe ends are heated and pressed together to form a fused joint. Used for rising mains and PE underbores.
Electrofusion: Joining method for PE pipe using electrically heated couplings. Useful for smaller fittings and tight spaces where butt welding is impractical.

Site Conditions

Greenfield: Undeveloped land with no existing infrastructure. Faster productivity rates, fewer constraints, lower cost per metre than brownfield work.
Brownfield: Existing developed area with live infrastructure (water, gas, electrical, telecommunications) requiring careful work. Productivity drops significantly compared to greenfield.
Live road: Construction within a road that remains open to traffic. Adds traffic management cost, restricts working hours, requires water-filled barriers, demands stabilised sand backfill, and typically slows productivity by 30-50% compared to closed-road work.
Live services: Existing underground utilities — gas, electrical conduits, telecommunications (Telstra, NBN), other water mains, sewer — that must be located, protected, or carefully avoided during excavation.
Traffic control: Personnel, signage, and equipment required to manage vehicles around a worksite. Cost includes traffic controllers, traffic management plans, and sometimes police presence for major roads.
Geotech: Geotechnical investigation and supervision. Soil, rock, and groundwater conditions drive much of the cost of excavation, shoring, dewatering, and backfill. Geotech reports inform productivity rates.
Dewatering: Removal of groundwater during excavation. Methods range from simple sump pumping to wellpoint systems for high-water-table sites. Required for deep sewer, pump stations near water tables, and stormwater works.
IOP (Interim Operating Pump Station): A temporary pump station, typically using a 25,000-litre poly tank, installed to service a development before a permanent pump station is built. Includes buoyancy slab to prevent the tank floating in high water tables, electrical commissioning, and a fenced compound.
Buoyancy slab: Concrete slab cast under a poly tank or similar lightweight structure to prevent it floating in high-groundwater conditions. Standard component of IOP installations.

// LIVING DOCUMENT

This glossary grows as we add new content. If a term you need isn’t here — or if you spot something we’ve described inaccurately — tell us. We’d rather get it right than be polite about it.

Request an estimate → 0451 404 645

Glossary. The terms estimators actually use.