French Drain Case Study: Managing Runoff in Shellharbour

Addressing Water Ingress Challenges in Shellharbour

In Shellharbour, a homeowner encountered a critical and worsening issue with water ingress. Rainwater from two adjacent properties, situated at a higher elevation, began to flow into their garden and infiltrate beneath the house’s foundation. This unwelcome water intrusion caused extensive damage to the flooring, promoted rising damp, and facilitated mould growth within the property, jeopardising recent renovations.

How Can You Identify Signs of Water Intrusion?

This issue originated from both surface runoff and subsurface water flowing downhill from the back and side yards of neighbouring properties. Without an effective drainage solution to intercept this water, it inevitably made its way beneath the house.

Creating an Effective Drainage System

CS Plumbing designed and implemented a gravity-fed French drain system intended to capture and redirect water before it could reach the foundation of the house.

This project comprised several crucial components:

A French drain system meticulously designed to collect both surface and subsurface water from neighbouring properties, efficiently channeling it through gravity to a concrete pit.
A 100mm PVC pipe running from the pit to the curb, featuring strategically drilled holes in the curb to ensure optimal water discharge.
Three new, larger-diameter Colorbond metal downpipes, replacing the original smaller versions, linked to new 100mm PVC piping that leads 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 to contain the adjacent yard.
Efficient soil removal on-site facilitated by a dumper to ensure smooth management of the worksite.

What Measures Can Be Implemented for Effective Water Management?

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