French Drain Case Study: Managing Runoff in Shellharbour

Addressing Water Ingress Challenges in Shellharbour

In Shellharbour, a homeowner encountered a persistent and worsening issue with water ingress. Water from two elevated neighbouring properties began to flow into their garden, eventually seeping beneath the home's foundation. This unwanted water intrusion caused extensive damage to the flooring, encouraged rising damp, and promoted mould growth within the property, jeopardising recent renovations.

How Can You Identify Water Intrusion Issues?

The water ingress problem originated from both surface runoff and subsurface water flowing downhill from the back and side yards of adjacent properties. Without an effective drainage solution to intercept this water, it inevitably flowed beneath the house.

Creating an Effective Drainage Solution

CS Plumbing designed and implemented a gravity-fed French drain system aimed at capturing and redirecting water before it could reach the home's foundation.

This project comprised several critical components:

A French drain system specifically developed to gather both surface and subsurface water from neighbouring properties, efficiently channeling it through gravity to a concrete pit.
A 100mm PVC pipe extending from the pit to the curb, equipped with strategically drilled holes in the curb to ensure optimal water discharge.
Three new, larger-diameter Colorbond metal downpipes, replacing the original smaller versions, connected to new 100mm PVC piping leading to the curb.
A retaining wall system constructed along the boundary, utilising concrete sleepers and galvanised steel posts, with auger holes drilled using an excavator to create a sturdy barrier to hold back the adjacent yard.
Efficient soil removal on-site conducted with a dumper to streamline worksite management.

What Effective Measures Can You Implement for Water Management?

The newly installed system now effectively captures both surface and subsurface water at the property boundary, ensuring it is diverted away from the home. The homeowner has achieved a durable, low-maintenance solution that safeguards the foundation, flooring, and their investment in renovations.