This project involved the construction of a high-end five-townhouse designer development where efficient stormwater management and space optimisation were critical components of the overall design.
Due to site constraints and the architectural layout of the development, the project required the installation of multiple underground Aquacomb® stormwater detention and pump systems fitted with submersible pumps beneath the shared driveway area. These systems were designed to manage stormwater effectively while maximising usable space across the development.
The majority of the underground tanks were installed within a trafficable driveway zone, with sections of the project also incorporating permeable paving to assist with water management and environmental performance.
The Challenge
While underground stormwater systems are common in medium-density developments, this project presented several unique construction challenges.
A significant structural beam spanned across the driveway between the townhouses, creating a restricted-height access zone directly above the excavation area. This prevented the use of larger excavation equipment that would normally be utilised for deep underground tank installations.
At the same time, the underground detention systems required substantial excavation depths, creating a complex construction environment where:
- Excavation had to be completed using smaller machinery.
- Soil removal became more labour-intensive.
- Access restrictions impacted productivity.
- Strict quality control measures were required during installation.
- Multiple systems had to be installed across five separate dwellings.
Given the location beneath a trafficable driveway, the installation also needed to achieve long-term structural performance capable of withstanding vehicle loads without compromising the stormwater infrastructure.
Our Approach
DE WALKERS developed a construction methodology that balanced site access limitations with the technical requirements of the stormwater design.
Key elements included:
- Careful staging of excavation works using compact machinery.
- Detailed planning of spoil removal logistics.
- Precise installation of underground detention tanks within restricted work zones.
- Coordination of submersible pump installations and associated infrastructure.
- Quality control procedures to prevent contamination and ensure reliable system operation.
- Compliance with engineering requirements for trafficable loading conditions above the tanks.
Particular attention was given to ensuring the systems operated effectively while protecting the dwellings from potential stormwater issues and maintaining long-term reliability.
The Outcome
Despite the restricted site conditions and complex installation requirements, the underground stormwater systems were successfully installed across all five townhouses.
The project demonstrated how careful planning, attention to detail, and practical construction expertise can overcome significant site constraints without compromising quality.
The completed installation delivered:
- Efficient underground stormwater management.
- Space-saving design solutions for a medium-density development.
- Reliable submersible pump operation.
- Trafficable driveway performance above the tank systems.
- Integration with permeable paving and broader site drainage strategies.
- A high-quality outcome despite challenging access conditions.
Key Takeaway
This project highlights DE WALKERS’ ability to deliver technically challenging infrastructure solutions within constrained construction environments.
By combining practical construction knowledge with detailed planning, we successfully installed complex underground stormwater systems beneath a restricted-access driveway, proving that even the most challenging site conditions can be managed without compromising quality, safety, or long-term performance.
Project Type: Five Designer Townhouses
Location: Victoria
Special Feature: Trafficable underground Aquacomb® stormwater detention systems with submersible pumps installed beneath a restricted-access shared driveway.
Delivered By: DE WALKERS – We Build the Trust.