French Drain Case Study: Runoff Management In Shellharbour

Effective Solutions for Water Ingress Problems in Shellharbour

A resident in Shellharbour encountered a serious and worsening problem with water ingress. Water from two neighboring properties situated at higher elevations began to flow into their yard and infiltrate beneath the home’s foundation. This intrusion caused damage to the flooring, promoted rising damp, and led to mould growth inside the house, threatening the structural integrity of recent renovations.

How to Identify the Main Causes of Water Intrusion

The source of the water ingress was traced to surface runoff and subsurface water flowing downhill from the back and side yards of adjacent properties. In the absence of adequate drainage systems to intercept this flow, the water inevitably made its way beneath the house, causing significant issues.

Designing an Effective Drainage System

CS Plumbing developed and implemented a gravity-fed French drain system tailored to capture and redirect water before it could reach the foundation of the home.

The project encompassed several crucial elements:

• A French drain system engineered to collect both surface and subsurface water from neighboring lots, channeling it via gravity to a concrete pit.
• A 100mm PVC pipe extending from the pit to the curb, featuring strategically placed drilled holes for effective water discharge.
• Three newly installed, larger-diameter Colorbond metal downpipes that replaced the original smaller units, connected to the new 100mm PVC piping leading to the curb.
• A sturdy retaining wall system constructed along the boundary using concrete sleepers and galvanised steel posts, with auger holes excavated to create a secure barrier to hold back the adjacent yard.
• Efficient soil removal carried out on-site using a dumper for streamlined site management.

Implementing a Robust Water Management System

The newly established drainage system effectively captures surface and subsurface water at the property boundary, directing it away from the home. The homeowner now benefits from a durable, low-maintenance solution that protects their foundation, flooring, and investment in renovations.