French Drain Case Study: Managing Runoff in Shellharbour

Addressing Water Ingress Challenges in Shellharbour

In Shellharbour, a homeowner encountered a serious and worsening problem with water ingress. Rainwater from two adjacent properties situated at a higher elevation began to flow into their garden and infiltrate beneath the foundation of their house. This water intrusion led to considerable damage to the flooring, contributed to rising damp, and promoted mould growth within the property, jeopardising recent renovations.

How Can You Identify Signs of Water Intrusion?

The 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 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 foundation of the house.

This project incorporated several critical components:

A French drain system meticulously engineered 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, featuring strategically drilled holes to ensure optimal water discharge.
Three newly installed, larger-diameter Colorbond metal downpipes, replacing the original smaller versions, linked 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 form a robust barrier to hold back the adjacent yard.
Efficient soil removal conducted on-site with a dumper to streamline site management.

What Measures Can You Implement for Effective Water Management?

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