Mascot Pits are the only engineer certified and tested Glass Reinforced Concrete (GRC) pits in Australia – they are suitable for all load ratings and installations. Mascot GRC Pits are designed to be used as an alternative to traditional steel reinforced precast concrete drainage pits and there’s no need to concrete encase or add a concrete collar – saving you time and money.

Due to the nature of the material, pipe entries can be done on site in any number of locations and sizes – no need to core-drill, no limitations with old fashioned knockouts and certainly no shattering or patching. Mascot’s unique Glass Reinforced Concrete is a composite of fibreglass and concrete technologies. It has the benefit of both products; the solidity of concrete and the high instantaneous strength of resin fibreglass.

The easiest pipe entries in the industry

GRC Drainage Pits

Mascot GRC Drainage Pits are heavy-duty for all load ratings, however, lightweight to ease installation and reduce transport costs. Proven compliance, exceptional durability, and reliable performance in every installation. Trusted by councils, builders, and engineers across Australia to control stormwater runoff, protect local waterways, and keep projects performing at their best year-round.

Below is a list of standard sizes of Mascot precast GRC Pits and Risers. All Mascot Pits are engineered and approved for installations to a depth of 5000mm, and we have stock Australia-wide.

Understanding Stormwater Drainage Systems

Mascot Engineering’s stormwater drainage systems capture and manage rainwater flows away from properties and into the drainage network. The systems handle normal rainfall as well as rainstorm events, reducing the possibility of flooding, erosion, and pollutants entering local waterways.

Our drainage pits, made from Glass Reinforced Concrete (GRC), connect to pipes, channels, and gross pollutant traps to ensure sediments, litter, and pollutants are trapped before reaching creeks, rivers, or the ocean. Stormwater runoff, including excess stormwater during heavy rain events, must be managed to protect water quality in the sea, rivers, and lakes, safeguard surrounding land, and meet local government requirements.

Whether for council road upgrades, residential drives, commercial developments, or large-scale projects, Mascot Engineering has solutions used successfully throughout Australia on a wide variety of sites and soil types. Our drainage work is relied on across Australia, from steep slopes to hard surface areas, landscaped areas, and coastal sites near the sea. We have been trusted throughout Australia for dependability and long service life.

Technical, Regulatory & Product Specifications of GRC Stormwater Drainage Pits

Surface and Subsurface Integration

Mascot’s GRC drainage pits have been designed for surface and subsurface stormwater drainage applications. They are directly connected to pipes, channels, and gross pollutant traps, conveying flows from hard surfaces, roofs, and landscaped areas. This flexibility allows the GRC drainage pits to remain effective in a variety of applications, including council, residential, commercial, and infrastructure contexts across Australia.

Durable GRC Construction for Long-Term Performance

Each pit is made from Glass Reinforced Concrete (GRC) and provides an exceptional strength-to-weight ratio in comparison to standard concrete, all while being resistant to erosion, chemical degradation, and adverse weather conditions. There are many sites that have challenging soil properties and severe slopes, so GRC is well-suited for these applications. GRC supports fast installation methods, all while providing a structure that is guaranteed for decades of use.

Range of Sizes, Load Ratings, and Grate Options

Mascot’s GRC drainage pits come in sizes from small 300 mm² pits through to larger 1,200 mm² pits for residential, commercial, and infrastructure projects. They can be made up to 5,000 mm deep and are located in warehouses across Australia for fast delivery.

Each pit can be made with various load ratings under AS3996, with pedestrian, driveway, and heavy vehicle zones available. Galvanised mild steel grates are designed for light use, while reinforced GMS grates and frames suit high-load situations, and access covers are available for secure, sealed installations where surface access is required. Stainless steel heelproof grates are made from grade 304 or 316, and are corrosion resistant. Our grates can be produced from DS0 to DS6 and load classes A to C. They are suitable for public spaces and landscaped areas.

Construction using GRC allows adjustment processing on-site without the need to core or breakout, therefore improving delivery for all installations. Overall project delivery is improved, costs are saved, projects hit budgets, no time is lost, work is not compromised, and site cracking is avoided. With a variety of sizes, load ratings, and grates available, Mascot’s GRC drainage pits provide efficient stormwater management and years of reliable service in various site environments and conditions.

Designed for a Variety of Site Conditions

Mascot’s GRC drainage pits can be installed in both new developments and existing sites, helping keep water quality acceptable by catching debris, sediment, and contaminants at the source, which in turn helps maintain the condition of the receiving waters.

They lessen erosion and mitigate flooding problems whilst allowing appropriate development practices to safeguard land, plants, infrastructure, and the environment. This helps maintain the health of waterways, from creeks to rivers and the sea.

These pits can also be integrated with on-site detention systems to slow the release of collected water, helping to minimise peak flows and further reduce the impact on surrounding drainage infrastructure.

Compliance with Local and National Standards

Each of Mascot’s GRC drainage pits is engineered to meet local council specifications and national standards, including the National Construction Code (NCC) and Water Sensitive Urban Design (WSUD) principles. The following checklist covers common points assessed by councils across Australia:

• Approved local council stormwater systems: Ensure drainage pit designs are constructed in accordance with the approved stormwater management plan and local development conditions.
• Connection to approved outlets: Check that your pit will connect through pipes, channels, or other drainage works approved by the council, and will not cause any harm to your neighbour’s property.
• Capacity and flow control: Check that an appropriate pit size has been commissioned to manage stormwater runoff and the peak flows likely to occur during heavy rainfall, preventing flooding and resulting erosion.
• Pollutant and sediment control: Include provisions for gross pollutant traps or sediment baskets to prevent pollutants and sediment from travelling into local waterways, surrounding plants, or landscaping.
• Access for inspection and maintenance: Position drainage pits to ensure safe access for cleaning and inspections by the council.
• Adherence to national and state standards: Ensure compliance with the NCC and WSUD principles for water quality and sustainability requirements.

Environmental Performance and Water Quality Protection

By capturing debris, sediment, and contaminants at the source, Mascot’s GRC drainage pits can help maintain water quality in surrounding catchments. They minimise erosion and manage flooding risks while allowing suitable development practices to remain intact, protecting land, plants, infrastructure, and the environment, and helping to maintain waterway health from creeks to rivers and the sea.

Best Practice Applications of GRC Drainage Pits

Our GRC drainage pits have been successfully installed in council upgrades, residential developments, and large-scale infrastructure projects across Australia. These case studies highlight how the right pit size, load rating, and grate selection can improve stormwater management, protect local waterways, and ensure long-term site performance.

What Our Clients Say

Councils, builders, and engineers across Australia choose Mascot Engineering for GRC drainage pits they can trust. Hear from professionals who value our product quality, compliance, and reliable performance on projects of every scale.

Key Considerations When Choosing the Right Drainage Pit

Choosing the right drainage pit ensures long-term performance, compliance, and ease of maintenance. When planning your stormwater drainage work, consider the following points:

• Match the pit size to site conditions: Before choosing a drainage pit size, ensure you understand rainfall intensity, catchment area, and anticipated stormwater flows into the pit to confirm it has the correct capacity.
• Select the appropriate load rating: Ensure that the drainage pit and grate meet the appropriate AS3996 for your situation, be it pedestrian, driveway, or heavy-vehicle.
• Consider the soil type and slope: Select pit materials and configurations that will ensure acceptable performance in difficult ground or during harsh slope conditions.
• Plan for pollutant control: Incorporate gross pollutant traps, sediment baskets, and drainage pit accessories to protect local waterways and maintain water quality.
• Allow for future maintenance: Position pits for easy access to remove sediment, debris, and litter without disrupting the surrounding infrastructure.
• Confirm compliance with local requirements: Check that the pit design meets local council, NCC, and WSUD standards before installation.

Mascot Engineering’s GRC drainage pits have been designed considering the above aspects to deliver strength, flexibility, and compliance for effective stormwater management solutions throughout Australia. Our drainage pits are perfect for residential, commercial, or infrastructure applications, built and designed to operate for decades.

Future-Proof Your Development with Premium GRC Drainage Pits

Choosing the right supplier is just as important as choosing the right drainage pit. For over 100 years, Mascot Engineering has been trusted across Australia to supply high-quality GRC drainage pits for projects of every scale.

Here’s why engineers, councils, and builders choose Mascot:

• Specialists in GRC drainage pits, risers, grating, and access covers.
• Modular designs for fast installation and long-term durability.
• Products that meet NCC and local council drainage standards.
• Proven track record in roads, infrastructure, and development projects.
• Local support and site-specific technical expertise.

From residential builds to major infrastructure upgrades, our GRC drainage pits help manage stormwater runoff, protect land and assets, improve water quality, and support long-term environmental outcomes.

FAQs

• What is stormwater drainage?

Stormwater drainage refers to infrastructure and systems such as drains, pits, and pipes designed to manage excess rainwater or stormwater runoff from surfaces like roofs, hardscapes, and paved areas. It helps prevent flooding, erosion, and contamination of local waterways.

• How does stormwater drainage work?

Stormwater drains capture the rainwater from site using drains, inlets and GRC drainage pits until it is directed or carried into underground pipes, detention tanks, or creeks, or into a stormwater network. These systems help prevent property flooding and reduce contaminants from entering rivers and lakes.

• What is the difference between drainage and stormwater?

Drainage refers to the systems that remove excess water from an area, while stormwater is specifically runoff generated from rainfall or melting snow on hard surfaces. Stormwater is the water that needs management, and drainage is the method used to control it.

• What are the four types of drainage in stormwater systems?

There are four main types of drainage systems used in property and infrastructure projects, all of which form part of broader stormwater systems.

Surface drainage systems include open channels, level grading, humps and hollows, and grassed waterways that redirect stormwater runoff away from hard surfaces and roads.

Subsurface drainage systems, such as French drains, use gravel-filled trenches with perforated pipes to collect and move groundwater away from structures.

Slope drainage systems use pipes installed on an incline to carry runoff away from sloping terrain, helping to prevent erosion and waterlogging.

Downspouts and gutter systems collect rainwater from roofs and direct it toward drains or into other components of a stormwater system.

• How can poorly managed stormwater impact communities and the environment?

Poorly managed stormwater can cause flooding, damage property and infrastructure, and erode soil. It can also carry pollutants into waterways, reduce water quality, and harm aquatic life.

• Why is stormwater drainage important for property and infrastructure?

Effective stormwater drainage reduces the risk of flooding, erosion, and soil degradation on properties and infrastructure. Good stormwater drainage stops contaminants like oil, rubbish, and sediment from entering our local waterways and ensures that property owners and managers are meeting their obligations under council permits and environmental regulations.

• What is the difference between stormwater detention and retention?

Stormwater detention is when stormwater is stored temporarily before being released at a controlled rate during low-frequency storm events. The controlled release helps limit the risk of flooding and erosion. Stormwater retention is when stormwater is held for a longer period to soak into the ground or be reused for irrigation purposes. Both detention and retention are used in stormwater systems to manage flows and reduce their impact on local waterways.

• Who owns stormwater drains?

For most of Australia, property owners are responsible for stormwater drainage infrastructure on their property, including gutters, downpipes, pits, and connections. Local councils are responsible for drains in public spaces like kerbs, channels, and roads.

• What is the best material for drainage around the house?

GRC, PVC, HDPE, and/or geotextile-lined gravel could all be used for drainage around the house. GRC is a very durable material with a high load capacity for the long term. PVC and HDPE are chemically resistant, lightweight materials. Geotextiles help filter out sediment while maintaining the physical structure of the soil.

• How often should drainage systems be maintained?

Drainage systems should be cleaned at least twice a year, primarily before and after the wet season. Some sites experience a lot of stormwater runoff or generate significant debris due to landscaping, so these sites may require more frequent inspections to maintain drainage systems at optimal functionality.