Wunan Medical Centre – Kununurra WA

Project Background

Kununurra Medical Centre is conveniently located in the centre of Kununurra at a purpose-built facility adjacent to Kununurra District Hospital. It is owned and operated by The Wunan Foundation, an East Kimberley Aboriginal development organisation. The only private practice in town, Kununurra Medical caters to the whole community.

The Problem

High water tables are prevalent throughout the shire. As a result, stormwater runoff attributed to development may exit the property due to the subsoil’s reduced capacity for infiltration. Traditionally, the Shire has permitted discharge into the stormwater system, but for this project, permeable sandy topsoils allow stormwater to infiltrate into the ground over time. The medical centre needed to update its stormwater management to minimise the risk of localised flooding caused by increased stormwater run-off from impervious surfaces.

Initially, consultants proposed the use of precast concrete soakwell kits.  However, with the groundwater table being very high, the concrete soakwells were not suitable due to their poor infiltration speed and capacity. Consequently, the design was revised to include a modular system where infiltration and trafficabilty were the key objectives.

The Solution

The works Contractor contacted the design team at Global Synthetics for assistance. After some deliberation and consultation, ProTank® was put forward. ProTank® is a unique modular subsurface drainage system designed to collect water at its source. ProTank® has the flexibility to infiltrate, attenuate, detain or harvest water for re-use. It has been widely used for subsurface stormwater management across many projects Australia-wide.

ProTank®’s structural elements or ‘plates’ carry a unique domed webbing profile providing exceptional strength making it the perfect choice to be installed under driveways, car parks, roads, landscaped areas and other trafficable applications.

Furthermore, the pre-designated ports allow direct connection of stormwater pipes, negating the need for crude ‘break-throughs’ which can compromise the structural integrity of its plates. Ultimately, the ProTank® single height and ultra-duty setup was proposed. With the additional use of Global Synthetic’s robust multi directional geogrid, Secugrid® 30/30, which offered base course stabilisation and reinforcement, the amount of earth cover needed was minimised to 700mm deep.   Using a geogrid has extended the service life of the ProTank® system which will now have a design life of 100 years under 30t vehicle traffic* and will infiltrate its full capacity given that the tank base will remain above the groundwater table.

Results

ProTank® and Secugrid® were approved and the system was successfully installed. ProTank® proved to be cost efficient, light weight and easy to install.  While, Secugrid® was also extremely efficient during install thanks to the extremely low recoil memory and 4.75m roll width, minimising overlap wastage.

By tailoring our design solution to meet the Contractor’s performance and economic requirements, Global Synthetics ensured end to end support throughout the entire design and project stages.