Case Study: Restoring Stormwater Capacity — Gold Coast Seafront Residence

Project Snapshot

• Client: Architect‑designed beachfront home in Main Beach, QLD

• Problem: Garden floods after every summer downpour; pooling undermining retaining wall

• Pipe Network: 90 mm PVC stormwater line, 32 m long, connected to kerb outlet

• Turnaround: 2‑hour diagnostic, 1 day remediation

• Tech Utilised: CCTV crawler, hydro‑excavation, sectional pipe bursting, HD‑PE pull‑through liner

1. The Challenge

1.1 Visible Symptoms

• Knee‑deep puddles forming within 20 minutes of rainfall

• Saltwater staining along basement blockwork

• Mosquito breeding reports from neighbours

1.2 Investigation Findings

Sequential CCTV passes exposed:

1. Sand Intrusion: 18 m section half‑filled with fine coastal sand.

2. PVC Deformation: Crushed pipe at 14 m mark due to previous landscaping works.

3. Corroded Kerb Outlet: Cast‑iron flap permanently stuck closed.

“A beachfront block amplifies every drainage flaw—salt, sand and shifting ground give pipes a hard life.”
— Principal Technician, SEQ Blocked Drains

2. Solution Strategy

Phase 1 – Immediate Flow Restoration

• Hydro‑Vac Excavation: Safe exposure of buried line at failure point.

• High‑Volume Flush: 75 mm sand jet nozzle, 60 L/min, cleared 25 kg of sand.

Phase 2 – Structural Renewal

1. Sectional Pipe Bursting – 8 m crushed segment replaced with 100 mm HD‑PE (SDR 17) without trenching through manicured lawn.

2. Pull‑Through Liner – Seamless epoxy‑impregnated liner installed from burst section to kerb, ensuring uniform diameter and salt‑resistance.

3. Kerb Outlet Upgrade – Swapped corroded flap for UV‑stabilised PVC grate and flap combo.

2.1 Equipment & Materials