Using the Flex MSE Vegetated Wall System to achieve streambank stabilisation.
The Goal:
The goal of the Taiaotea Stream Environmental Enhancement project in Browns Bay was to rehabilitate the stream corridor while futureproofing the channel against erosion and stormwater damage. A key focus of the project was the reconstruction and realignment of the stream bank using the Flex MSE Vegetated Wall System supplied by Advance Landscape Systems, selected for its low-impact, high-performance characteristics.
The Challenge:
The Taiaotea Stream had been facing issues with bank instability, erosion, and vegetation degradation which are common problems in urbanised catchments with modified flows and aging infrastructure. To address this, Healthy Waters commissioned a redesign of the stream alignment, prioritising naturalised elements and bank stability while also creating a more resilient and biodiverse corridor.
The Solution:
Advance Landscape Systems supplied the Flex MSE Vegetated Wall System, which was installed along critical sections of the realigned stream by C.W. Glasgow Contractors. The Flex MSE system was chosen by Design Consultants Isthmus Group for its ability to provide both structural retention and a naturalised vegetated finish, ideal for a living streambank environment.
To integrate the Flex MSE walls into the natural stream setting, local grass seeds and groundcover mix was applied to the bags using a hydroseeder, selected for their low-maintenance performance and fast establishment. Native carex secta grasses were planted directly into the top rows of bags to provide shade for the stream habitat. This planting complemented surrounding riparian enhancement zones, supporting improved water quality and habitat.
Why Flex MSE was chosen for this project
- Green Infrastructure: Flex MSE is a soft-engineering solution designed for riparian and wetland environments. Its vegetated face enhances ecological function, unlike concrete or block walls.
- Resilience to Urban Runoff: The geosynthetic design allows for flexibility and resilience under fluctuating moisture conditions and moderate stormwater surges common in urban streams.
- Stream Realignment Compatibility: The lightweight and modular nature of the system made it well-suited for tight urban working environments and adaptive to changes in stream alignment.
- Construction Practicality: The system is quick to install with minimal heavy machinery, reducing disruption to surrounding community and stream ecology.
The Flex MSE Vegetated Wall System played a pivotal role in the success of the Taiaotea Stream enhancement project. By combining performance engineering with ecological sensitivity, this solution demonstrates how infrastructure can work in harmony with natural systems — achieving resilience, aesthetic, and environmental outcomes in a single design.