Stormwater & Drainage Guide for Australian Homeowners

How Stormwater Systems Work

Stormwater is rainwater that runs off roofs, paving, and gardens. It flows through downpipes into underground pipes (stormwater drains) that discharge to the street or a waterway. Stormwater is separate from the sewer system — sewer carries wastewater, stormwater carries rainwater. Never connect stormwater to the sewer (and vice versa) — illegal and causes both systems to fail.

Common Drainage Problems and Causes

• 1 Water pooling on lawn: sub-surface drainage inadequate or clay subsoil preventing absorption
• 2 Water entering garage or sub-floor: ground grades toward building, or stormwater system blocked/overloaded
• 3 Neighbour's water coming onto your property: their grading directs water to your boundary — council mediation may be needed
• 4 Overflowing gutters: blocked or incorrectly sized gutters and downpipes
• 5 Tree root intrusion in underground drainage: common cause of recurrent blockages

CCTV Drain Inspection

For recurrent drainage blockages or suspected pipe damage, a CCTV drain inspection ($300–$600) inserts a camera into the drain to identify: tree root intrusion, collapsed pipes, illegal connections, and partial blockages. This removes guesswork before expensive excavation.

Solutions for Common Problems

• 1 Surface pooling: surface channel drain (Stormtech, ACO) captures water at low point and connects to stormwater
• 2 Sub-surface saturation: French drain (agricultural pipe in gravel trench) captures and drains subsurface water
• 3 Water entering from neighbours: create a swale (shallow grassy channel) to direct water around your building
• 4 Inadequate system capacity: install a detention tank or soakage pit for peak-flow management