Managing Water Flow Around the Retaining Wall
Our team attended a property in Avalon Beach NSW 2107 where significant water was moving from the uphill lawn towards the retaining wall and surrounding garden area.
The drainage solution needed to manage both visible surface runoff and water travelling through the saturated ground.
A new drainage trench was excavated approximately 5 metres towards the existing stormwater line, with the route carefully taken around an existing frangipani tree.
Installing Surface and Subsoil Drainage
A new surface drain was installed where water was flowing down from the retaining wall, providing a dedicated collection point for runoff.
Alongside this, an ag-drainage system was installed through the excavated area to collect water moving below the surface.
The ag drains were connected at multiple points into a new hard PVC main drainage line, which carries the collected water towards the property's existing drainage system.
This combination allows the system to manage water at two levels: surface runoff entering through the collection drain and groundwater entering through the subsoil drainage.
Using Blue Metal to Improve Groundwater Drainage
The new subsoil drainage was surrounded with blue metal aggregate before the trench was reinstated.
The spaces within the aggregate create a permeable drainage zone, allowing groundwater to move more freely towards the ag pipe rather than remaining trapped within saturated soil.
Once collected, the water can then enter the main PVC drainage line and be carried away from the affected area.
Connecting Into the Existing Drainage System
The new drainage was integrated with the property's existing stormwater and easement drainage infrastructure.
A riser and surface-level drain were also installed at the existing easement connection to provide an additional relief and access point within the system.
Once installation was complete, the drainage was tested and commissioned before the trenches were backfilled. Excess excavated material and construction waste were then removed from the property.
Improving Drainage Around the Retaining Wall
For this Avalon Beach property, installing both surface and subsoil drainage provided a more complete solution than relying on a single drain.
Surface runoff can now be intercepted where it reaches the retaining wall area, while the ag drainage helps collect water moving through the surrounding ground.
Both feed into the dedicated PVC drainage line, giving excess water a controlled route towards the property's existing drainage infrastructure.
Related Stormwater & Drainage Services
Pure Plumbing Professionals provides Stormwater Drainage, Subsoil Drainage, Residential Plumbing and general Drainage services throughout Avalon Beach and surrounding Sydney suburbs.
This can include ag drain installation, retaining wall drainage, surface drains and drainage improvements for areas affected by persistent groundwater or runoff.
