French Drain Case Study for Shellharbour's Runoff Management

Addressing Water Ingress Challenges in Shellharbour

In Shellharbour, a homeowner encountered a serious and worsening problem with water ingress. Water originating from two adjacent properties, situated at a higher elevation, began flowing into their garden and infiltrating beneath the house's foundation. This water intrusion caused substantial damage to the flooring, promoted rising damp, and led to mould growth within the property, jeopardising recent renovations.

Recognising the Indicators of Water Intrusion

The issue arose from both surface runoff and subsurface water flowing downhill from the back and side yards of adjacent properties. Without an adequate drainage system to intercept this water, it inevitably made its way beneath the house.

Creating an Effective Drainage Solution

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

This project encompassed several key elements:

A French drain system meticulously crafted to capture 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, featuring strategically drilled holes in the curb to ensure optimal water discharge.
Three newly installed, larger-diameter Colorbond metal downpipes, which replaced the original smaller versions, now connected to new 100mm PVC piping leading to the curb.
A retaining wall system constructed along the boundary, employing concrete sleepers and galvanised steel posts, with auger holes drilled using an excavator to create a robust barrier to retain the adjacent yard.
Efficient on-site soil removal carried out with a dumper to manage the worksite effectively.

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 directed away from the home. The homeowner has achieved a durable, low-maintenance solution that safeguards the foundation, flooring, and their investment in renovations.