French Drain Case Study: Managing Runoff in Shellharbour

Addressing Water Ingress Challenges in Shellharbour

In Shellharbour, a homeowner encountered a serious and worsening problem with water ingress. Water from two adjacent properties, positioned at a higher elevation, began to flow into their garden and infiltrate beneath the house’s foundation. This intrusion led to considerable damage to the flooring, promoted rising damp, and encouraged mould growth within the property, jeopardising recent renovations.

How Can You Identify Signs of Water Intrusion?

The issue originated from both surface runoff and subsurface water flowing down from the back and side yards of neighbouring properties. Without an effective drainage solution to intercept this water, it naturally flowed beneath the house.

Developing a Comprehensive 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 involved several critical components:

A French drain system specifically designed 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, featuring strategically drilled holes 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 built along the boundary, using concrete sleepers and galvanised steel posts, with auger holes drilled by an excavator to create a robust barrier against the adjacent yard.
Efficient soil removal conducted on-site with a dumper to facilitate streamlined management of the worksite.

What Measures Can You Implement for Effective 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 secured a durable, low-maintenance solution that safeguards the foundation, flooring, and their investment in renovations.