French Drain Case Study: Managing Runoff in Shellharbour

Addressing Water Ingress Challenges in Shellharbour

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

How Can You Identify Signs of Water Intrusion?

The issue arose from both surface runoff and subsurface water migrating downhill from the back and side yards of neighbouring properties. Without an effective drainage solution to intercept this water, it inevitably flowed beneath the house.

Creating an Effective Drainage System

CS Plumbing designed and installed a gravity-fed French drain system capable of capturing and redirecting water before it could impact the home’s foundation.

The project involved several crucial elements:

A French drain system specifically tailored to gather both surface and subsurface water from neighbouring properties, efficiently directing it through gravity to a concrete pit.
A 100mm PVC pipe extending from the pit to the curb, equipped with strategically drilled holes to optimise water discharge.
Three new, larger-diameter Colorbond metal downpipes, replacing the existing smaller models, connected to new 100mm PVC piping leading to the curb.
A retaining wall system constructed along the boundary, using concrete sleepers and galvanised steel posts, with auger holes drilled by an excavator to create a robust barrier that holds back the adjacent yard.
Efficient on-site soil removal executed with a dumper to ensure seamless management of the worksite.

What Measures Can You Implement for Effective Water Management?

The newly established system now effectively captures both surface and subsurface water at the boundary of the property, ensuring it is redirected away from the home. The homeowner has secured a long-lasting, low-maintenance solution that safeguards the foundation, flooring, and their investment in renovations.