French Drain Case Study: Managing Runoff in Shellharbour

Addressing Water Ingress Challenges in Shellharbour

In Shellharbour, one homeowner encountered a pressing issue with water ingress. Water from two elevated neighbouring properties began to flow into their garden and permeate beneath the foundation of their home. This unrelenting water intrusion caused substantial damage to the flooring, promoted rising damp, and encouraged mould growth within the property, jeopardising the integrity of recent renovations.

How Can You Identify Signs of Water Intrusion?

The water ingress issue originated from both surface runoff and subsurface water flowing downhill from the back and side yards of adjacent properties. Without an adequate drainage solution to intercept this water, it inevitably made 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 foundation of the house.

The project consisted of several key components:

A French drain system meticulously engineered to collect 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 kerb, equipped with strategically drilled holes in the kerb to ensure optimal water discharge.
Three new, larger-diameter Colorbond metal downpipes, replacing the original smaller versions, linked to new 100mm PVC piping leading to the kerb.
A robust retaining wall system constructed along the boundary, utilising concrete sleepers and galvanised steel posts, with auger holes drilled using an excavator to create a solid barrier against the adjacent yard.
Efficient on-site soil removal conducted using a dumper to ensure effective management of the worksite.

Which Strategies Can You Implement for Effective Water Management?

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