★ 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, materials, manhole specs, authority terminology. Every term cross-links to where it appears in context.

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A working reference for the language of water and sewer infrastructure estimating in Australia. DTC numbers, encasement codes, pipe materials, manhole specifications, authority terminology. Every term cross-links to where it appears in context across our service pages. For the engineering experience behind the terms, see about, and for how we apply this knowledge to real estimates see our method. If a term you need isn’t here, tell us — we’ll add it.

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

Authorities

Sydney Water (SWC): The water and sewer authority for Greater Sydney. Publishes the Design and Construction Specifications used across NSW for SWC assets. Most water and sewer infrastructure estimating in Sydney references Sydney Water specs. See in context: Sydney & NSW →
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. See in context: Hunter Region →
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. See in context: Melbourne & VIC →
SA Water (SAW): Water and sewer authority for South Australia, covering Adelaide and regional centres. See in context: Locations →
Queensland Urban Utilities (QUU): Water and sewer authority for South East Queensland (Brisbane, Ipswich, Lockyer, Scenic Rim, Somerset). See in context: Queensland →
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. See in context: Water Estimating →
MRWA: Melbourne Retail Water Agencies — the joint body for Melbourne’s retail water businesses. Publishes shared technical specifications used across the Melbourne metropolitan area. See in context: Regional Victoria →

Standards & Codes

DTC: Deemed to Comply — the catalogue of standard drawings published within Sydney Water’s Design and Construction Specifications. Each DTC number defines a specific configuration that automatically meets compliance requirements under those specifications. DTCs are not the framework themselves — they’re standard solutions within Sydney Water’s broader specifications, which in turn align with the national WSA Code. Estimators reference DTC numbers to know exactly what materials, dimensions, and methods are required for a given component. See in context: Sydney & NSW →
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). See in context: Water Estimating →
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. See in context: Water Estimating →
DTC 2200: Sydney Water standard for a DN1200 sewer manhole. Specifies base thickness, wall thickness, reinforcement, and benching requirements. See in context: Sewer Estimating →
DTC 2203: Sydney Water standard for a DN1050 sewer manhole. Smaller than DTC 2200 with different reinforcement requirements. See in context: Sewer Estimating →
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. See in context: Sewer Estimating →
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. See in context: Sewer Estimating →
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. See in context: 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. See in context: Water Estimating →

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). See in context: Water Estimating →
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. See in context: Water Estimating →
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. See in context: Water Estimating →
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. See in context: Water Estimating →
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. See in context: Water Estimating →
OPVC: Oriented PVC pipe. Stronger than standard PVC, used where higher pressures or larger sizes are required. Sometimes substituted for DICL in design changes. See in context: Water Estimating →
RCP (Reinforced Concrete Pipe): Reinforced concrete pipe — the workhorse material for stormwater drainage. Heavy, durable, and available in large diameters from DN300 up to DN1500 and beyond. Joints are typically rubber-ringed for fast installation. Larger diameters often require on-site cutting to match chainage lengths — a labour-intensive step that’s often missed in generalist estimates. See in context: Stormwater & Deep Civil →
HDPE: High-Density Polyethylene — used for stormwater pipes where flexibility, lighter weight, or corrosion resistance is required over concrete. Available in various diameters with welded or socketed joints depending on the specification. See in context: Stormwater & Deep Civil →

Fittings & Components

RRJ (Rubber Ring Joint): Pipe joint method using a rubber ring seal. Quick to install. Standard for PVC and many DICL applications. See in context: Water Estimating →
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. See in context: Water Estimating →
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. See in context: Water Estimating →
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. See in context: Water Estimating →
Hydrant: Connection point for fire-fighting water supply. Installed at regular intervals along water mains, particularly in subdivisions. See in context: Water Estimating →
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. See in context: Water Estimating →
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. See in context: Water Estimating →
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). See in context: Water Estimating →
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. See in context: Sewer Estimating →
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. See in context: Sewer Estimating →
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. See in context: Sewer Estimating →
OSD (On-Site Detention): Stormwater detention systems installed on individual properties or developments to attenuate peak flows before discharge to the public stormwater network. Sizing per local council specifications. Typical components include detention tanks, orifice plates, and overflow paths. See in context: Stormwater & Deep Civil →
Culvert: Box-section or pipe structure carrying stormwater (or sometimes a watercourse) under a road, embankment, or other obstacle. Typically reinforced concrete, supplied as precast units. Sizing depends on catchment area and design storm event. See in context: Stormwater & Deep Civil →
Pit: Stormwater inlet structure (gully pit, junction pit, kerb inlet pit) collecting surface runoff into the underground stormwater network. Various standard types per state/council specification, with grates rated for traffic loading. See in context: Stormwater & Deep Civil →
Headwall: Reinforced concrete structure at the inlet or outlet of a culvert or stormwater pipe, retaining the surrounding embankment and protecting against erosion at the discharge point. Sized to suit pipe diameter and embankment slope. See in context: Stormwater & Deep Civil →
FRP tank: Fibre Reinforced Poly tank — lightweight, transportable holding tank typically used in Interim Operating Pump Stations. Easy to handle but fragile; can crack or flex under excessive compaction pressure during backfilling. The lightweight nature makes installation faster than precast concrete, but the handling and backfilling protocols have to be carefully managed. Note: this “FRP” refers to the material; not to be confused with Form-Reo-Pour, the in-situ concrete construction process. See in context: Pump Stations →
Form-Reo-Pour (FRP): In-situ concrete construction method — the three-step process of building bespoke concrete structures on site. Form = set up the timber or steel formwork that shapes the concrete. Reo = place the steel reinforcement (bars and mesh) inside the formwork. Pour = pour the concrete around the reinforcement, then strip the formwork once the concrete has cured. Used for OSD tanks, large pits, headwalls, and any stormwater structure too bespoke for precast solutions. Note: this “FRP” refers to the construction method; not to be confused with FRP tanks (Fibre Reinforced Poly), which is a plastic tank material. See in context: Stormwater & Deep Civil →
Class D pit and grate: Loading class designation for pit covers and grates under AS 3996. Class D is rated for heavy traffic loads such as carriageways, highways, and roads with commercial vehicle access. Other common classes: Class A (non-traffic / pedestrian), Class B (light traffic), Class C (medium duty). Class D pits and grates are significantly more expensive than lighter classes, and many estimators forget to allow for the correct class when reading the pit schedule. See in context: Stormwater & Deep Civil →
30-tonne excavator: The practical workhorse machine class for medium-depth civil work including water mains, larger sewer trenches, and stormwater installations. Capable of reaching approximately 6 metres in depth from surface level when dug directly. Beyond that, either a long-reach version or a ramped working surface is required. Significantly more productive than smaller machines on production runs with larger pipe diameters or deeper trenches. See in context: Sewer Estimating →
Control panel: The electrical brain of a pump station — houses the controls, sensors, motor starters, and protection devices that run the pumps and report status to the authority. Designed to authority specification, typically weatherproof and lockable. Connects to the SCADA/telemetry network for remote monitoring. See in context: Pump Stations →
SCADA / Telemetry: Supervisory Control and Data Acquisition — the system that allows the water authority to remotely monitor and control a pump station from a central operations centre. Telemetry refers to the wireless or wired data link between the station’s control panel and the authority’s monitoring network. Required on most permanent pump station installations and increasingly on interim setups too. See in context: Pump Stations →
Vent shaft and odour control: The system that vents gases from the pump station holding tanks to atmosphere, typically with carbon filters or biofilters for odour control in built-up areas. The vent shaft extends from the tank lid to above ground level, with the odour control unit mounted at or near the top. Specification depends on flow rates, proximity to occupied buildings, and authority requirements. See in context: Pump Stations →
Ramp excavation: The graded earth ramp dug down to working depth for deep pump station or other deep civil installations. Allows machines and personnel to work efficiently at depth without long-reach equipment. Adds significant volume to the total excavation, and most generalist estimators don’t account for it — calculating only the strict m³ of the final hole. The ramp’s geometry and gradient depend on the type of machinery being used. See in context: Pump Stations →

Sewer-Specific Terms

FIFM: Flow Isolation Flow Management — process and equipment used to manage live sewer flow during connection, diversion, or repair work. Includes flow isolation (stopping or redirecting upstream flow temporarily) and flow management (over-pumping, bypass setup, monitoring). Required by authorities for live sewer works to ensure no overflow or service disruption during construction. See in context: Sewer Estimating →
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. See in context: Sewer Estimating →
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. See in context: Sewer Estimating →
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. See in context: Sewer Estimating →
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. See in context: Sewer Estimating →
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. See in context: Water Estimating →
CCTV inspection: Closed-circuit television survey of completed sewer mains to confirm condition, alignment, and absence of defects. Standard authority requirement for new infrastructure. See in context: Sewer Estimating →
Underbore: Trenchless installation method — the pipe is pulled or pushed under an obstruction (road, river, building) without open excavation. Common methods include HDD (horizontal directional drilling), laser bore, and auger bore. Cost driven by ground conditions, casing requirements, and pit construction. See in context: Water Estimating →
Maintenance Chamber (MC): A 600mm diameter poly chamber installed on a sewer line for inspection and maintenance access. Replaced the older 300mm Maintenance Shaft, which proved too narrow for practical inspection and maintenance work. Smaller and cheaper than a full manhole, but adequate for routine access on shorter lines and lower-flow sections. See in context: Sewer Estimating →
Terminal Maintenance Shaft (TMS): The starting point of a sewer line at the dead-end of the network — the upstream-most point from which the sewer flow begins and runs downstream toward the authority main. For example, on a row of ten houses, the sewer pipe starts at a TMS at the first house and flows from there to the trunk sewer. See in context: Sewer Estimating →

Water-Specific Terms

Lead-in main: An extension of the water or sewer network from existing infrastructure to a new development or area. Typically required when the existing network can’t reach or can’t meet new demand. Routes can run through greenfield, farmland, or private property — the route, length, depth, and what’s in the way drive much of the cost. See in context: Water Estimating →
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. See in context: Water Estimating →
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). See in context: Water Estimating →
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. See in context: Water Estimating →
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. See in context: Water Estimating →
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. See in context: Water Estimating →
Rising main: Pressure pipe carrying sewage or wastewater from a pump station discharge to a gravity sewer or treatment works. Typically PE pipe with butt-welded or electrofused joints, sized to handle pump flow rates. Length and depth vary depending on the pump station’s position relative to the gravity network. See in context: Pump Stations →
Mains to Meter: The water service connection from a water main to a property’s meter assembly. The generic term covers any connection from main to meter, but is most commonly used when the main is not yet live (during a new subdivision build, before commissioning). Where the main is already pressurised, the equivalent operation is a Live Drilling or Tap-in. See in context: Water Estimating →
Live Drilling: The operation of connecting a new property service to a live (pressurised) water main, typically for a new house being developed on a Super Lot within an existing subdivision. Done under pressure using specialised tapping equipment so the main doesn’t have to be shut down. More expensive and risk-managed than a connection to a non-live main. See in context: Water Estimating →
Tap-in: The operation of connecting any non-residential service (commercial, industrial, irrigation, fire-fighting, or other) to a live water main. Same live-main technique as Live Drilling, but for connections other than a single house service. See in context: Water Estimating →
Super Lot: A single undeveloped block of land surrounded on all sides by already-developed lots within a subdivision. When a Super Lot is finally built on, the water main and sewer infrastructure servicing the surrounding lots are already live, so the new connection has to be made into pressurised mains via Live Drilling rather than a standard Mains to Meter. See in context: Water Estimating →

Construction Methods

Open-cut / open-trench: Standard excavation method — dig a trench, lay the pipe, backfill. Cheapest method when access allows. See in context: Water Estimating →
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. See in context: Water Estimating →
Laser bore: Trenchless installation method using a laser-guided system to maintain precise alignment of the pipe being pushed under an obstruction. The laser provides continuous reference for steering, allowing very accurate line and grade. Suitable for crossings where alignment tolerance is critical — including gravity sewer crossings where slope precision matters. See in context: Water Estimating →
Auger bore: Trenchless installation method using a rotating auger inside a steel casing to remove spoil as the casing is jacked forward under an obstruction. A laser bore is a lot more precise than an auger bore, but auger bore remains a standard, reliable method for many road crossings, casing installations, and pressure-pipe applications where tight grade tolerance is less critical. See in context: Water Estimating →
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. See in context: Water Estimating →
Free bore: Underbore where the carrier pipe is installed directly without an outer casing. See in context: Water Estimating →
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. See in context: Pump Stations →
Electrofusion: Joining method for PE pipe using electrically heated couplings. Useful for smaller fittings and tight spaces where butt welding is impractical. See in context: Pump Stations →

Site Conditions

Greenfield: Undeveloped land with no existing infrastructure. Faster productivity rates, fewer constraints, lower cost per metre than brownfield work. See in context: Water Estimating →
Brownfield: Existing developed area with live infrastructure (water, gas, electrical, telecommunications) requiring careful work. Productivity drops significantly compared to greenfield. See in context: Water Estimating →
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. See in context: Water Estimating →
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. See in context: Water Estimating →
Services search: The process of locating existing underground utilities (telecom, gas, electricity, water mains) before excavation, typically required within the top metre of soil. Includes Dial Before You Dig (DBYD) information, ground-penetrating radar, and potholing where needed. Mandatory step before any machine excavation in built-up areas. See in context: Water Estimating →
Trench stops: Stabilised sand or aggregate barriers placed within a trench at specified intervals on sloping ground (5–14% slope per WSA Code Table 7.5). Provide trench and pipe stability on slopes, preventing the bedding from migrating downhill. See in context: Water Estimating →
Concrete bulkheads: Reinforced concrete retaining walls cast into a trench at specified intervals on steeper ground (15–29% slope per WSA Code Table 7.5). More substantial than trench stops, required where slope exceeds the threshold for stabilised aggregate alone. See in context: Water Estimating →
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. See in context: Water Estimating →
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. See in context: Sewer Estimating →
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. See in context: Sewer Estimating →
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. See in context: Pump Stations →
Permanent pump station: A pump station built as a permanent piece of infrastructure, typically with a precast concrete wet well, in-situ concrete lid and base slabs, fenced compound with bollards, electrical commissioning, generator backup, and a permanent rising main connection. Designed for the long-term capacity of the development it serves. See in context: Pump Stations →
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. See in context: Pump Stations →
Method change: A variation to the agreed construction method during a project, often driven by unforeseen ground conditions, access constraints, or design clarification. For example, switching from open-cut to horizontal directional drilling because of an obstruction not shown on the original drawings. Method changes typically require a re-priced estimate covering different plant, productivity, and crew requirements. See in context: Variations & Design Change →

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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.

Glossary. The terms estimators actually use.