French Drain Case Study for Effective Runoff Management 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 situated at a higher elevation began to flow into their garden and infiltrate beneath the foundation of the house. This water intrusion caused substantial damage to the flooring, promoted rising damp, and encouraged mould growth within the property, jeopardising recent renovations.

How Can You Identify Signs of Water Ingress?

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

Creating an Effective Drainage System

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

This project included several critical components:

A French drain system specifically designed to collect both surface and subsurface water from adjacent properties, efficiently directing it through gravity to a concrete pit.
A 100mm PVC pipe extending from the pit to the curb, with strategically placed 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, using concrete sleepers and galvanised steel posts, with auger holes drilled by an excavator to create a robust barrier to hold back the neighbouring garden.
Efficient soil removal on-site carried out with a dumper to ensure smooth management of the worksite.

What Actions Can You Implement for Effective Water Management?

The newly installed system now efficiently 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 protects the foundation, flooring, and their investment in renovations.