Morphum were engaged to investigate, design and monitor construction for the remediation of the Awaruku Stream, to prevent sediment entering the Long Bay-Okura Marine Reserve downstream. Morphum designed a soft-engineering solution focusing on managing hydraulic energy within the stream system using sustainable ecological approaches including in-stream fish habitat creation and riparian planting with lizard habitat creation near the stream.

Protecting the mauri of the site as well as working within the projects timeframe and budget were paramount objectives. The Morphum team achieved this through the successful integration of multiple outcomes.

The project used an innovative combination of geospatial technology including drone footage and Pix4D, to provide high resolution design information and accurately assess the construction progress.

‍

‍

The solution included the installation of four riffle structures in the stream, as well as reducing the level of both left and right bank floodplains. The lowered sections of floodplain provide flood flow control, as well as adding variety to the habitat available. The levels of the floodplains are set to provide great Inanga spawning throughout a range of potential sea level rise estimates future proofing the design.

Overall, Morphum’s soft-engineering approach was a success, with the outcome being an award-winning project that materially decreased erosion. As the stream continues to develop, any effects of future erosion have also been minimised on account of the riffle structures and floodplains installed, while material susceptible to mobilisation has been stabilised.

‍

To learn more about our environmental engineering services, read through our page here:

Morphum Environmental Engineering Services