Stormwater Drainage Solutions — Prevent Flooding & Water Damage

Stormwater Challenges Unique to the Eastern Suburbs

Sydney’s Eastern Suburbs face a particular set of stormwater challenges. The area’s proximity to the coast means intense summer storms deliver heavy rainfall in short bursts. Many properties are built on sloping land — particularly in suburbs like Woollahra, Bellevue Hill, Rose Bay and Vaucluse — where water naturally flows downhill and concentrates at the lowest points. Older suburbs have ageing clay and concrete stormwater infrastructure that was designed for a fraction of the impervious surface area that exists today, thanks to decades of extensions, paving and pool installations.

The result is flooding. Water pooling in backyards, flowing into garages and subfloor areas, saturating foundations and, in severe cases, entering living spaces. Poor stormwater management is also a leading cause of retaining wall failure, driveway undermining and soil erosion on sloping Eastern Suburbs properties.

Mr Plumber designs and installs stormwater drainage systems that address these challenges, protect your property and comply with the requirements of Randwick, Waverley and Woollahra councils.

Our Stormwater Services

Stormwater System Design

Effective stormwater management starts with good design. We survey your property, measure roof catchment areas, assess overland flow paths, identify low points where water collects, and design a drainage system that captures and conveys water safely to the council stormwater main or an approved on-site disposal system.

Our designs comply with AS/NZS 3500.3 (Stormwater Drainage) and the specific requirements of your local council. For properties in the Randwick, Waverley or Woollahra council areas, we are familiar with each council’s stormwater policies, on-site detention requirements and connection standards.

Surface Drainage — Pits and Grates

Surface drainage pits and grates capture stormwater before it can pool or flow toward your building. We install:

• Strip drains along the base of retaining walls, garage entrances and patio edges to intercept sheet flow.
• Grated pits in low points of paved areas to collect and channel water into underground pipes.
• Bubble-up pits where the grade does not allow gravity drainage, using a controlled overflow to prevent flooding.

Pit locations and sizes are designed based on the contributing catchment area and the rainfall intensity for Sydney’s Eastern Suburbs.

Subsoil (Ag) Drainage

Subsoil drainage — also called agricultural or ag drainage — removes water from saturated soil to prevent rising damp, foundation damage and waterlogging of gardens and lawns. We install perforated ag pipe in a gravel-filled trench, typically at the base of retaining walls, along building perimeters and in low-lying areas.

Subsoil drainage is particularly important for Eastern Suburbs properties built on clay soils, which retain water and can cause significant hydrostatic pressure against basement walls and subfloor areas. Suburbs like Paddington, Woollahra and Darlinghurst — where many homes are built into hillsides with deep basement levels — benefit greatly from properly designed subsoil drainage.

On-Site Detention (OSD) Systems

On-site detention is a stormwater management strategy that temporarily stores rainwater runoff from your property and releases it at a controlled rate to the council stormwater system. This prevents downstream flooding by reducing the peak flow rate during heavy storms.

Most Eastern Suburbs councils require OSD for new developments, major renovations and any project that increases the impervious area of a site. We design and install OSD systems including:

• Underground detention tanks — precast concrete or polyethylene tanks buried below driveways, gardens or lawns.
• Above-ground detention — using landscaped basins or oversized pits where underground installation is not feasible.
• Orifice plates and flow-control devices — precision-sized outlets that control the discharge rate from the detention system.

Our OSD designs are modelled to meet the specific performance criteria set by your council and are submitted with the plumbing and drainage application for approval.

Blocked Stormwater Clearing

When existing stormwater drains block — from silt, leaves, tree roots or collapsed pipes — we clear them using the same high-pressure hydro jetting and CCTV camera equipment we use for sewer blockages. We also repair or reline damaged stormwater pipes to prevent recurring blockages.

Common stormwater blockage locations include:

• Stormwater pits filled with silt, leaves and debris.
• Pipe junctions where roots enter through gaps.
• Under-driveway sections where pipes have cracked or collapsed under traffic loading.
• Connection to council main where old clay pipes have deteriorated.

Stormwater Pipe Repair and Replacement

Damaged stormwater pipes can be repaired using trenchless pipe relining (for cracks, root damage and joint displacement) or replaced by traditional excavation (for fully collapsed sections). We assess the pipe condition with CCTV and recommend the most cost-effective repair method.

Council Requirements in the Eastern Suburbs

Each council in the Eastern Suburbs has its own stormwater management requirements:

Randwick Council requires OSD for all developments that increase impervious area. Stormwater must be connected to the council main — on-site absorption is generally not permitted. Detailed OSD calculations and hydraulic designs must be submitted with the development or complying development application.

Waverley Council has similar OSD requirements and additionally mandates water-sensitive urban design (WSUD) measures for certain developments, including rainwater tanks for toilet flushing and garden irrigation.

Woollahra Council requires OSD and may also require stormwater quality treatment devices (such as gross pollutant traps) for larger developments to protect downstream waterways and harbour water quality.

Mr Plumber is familiar with all three councils’ requirements and can prepare the necessary hydraulic documentation for your application.

Protect Your Property Before the Next Storm

Do not wait for the next big storm to discover your stormwater system is inadequate. Call 1800 247 474 to arrange a property drainage assessment and get a quote for stormwater improvements tailored to your Eastern Suburbs home or business.