In some circumstances - where bio-engineering by itself would not work - we recommend a project solution where we combine natural engineering and more conventional, hard interventions such as steel sheet piles and gabions.

These situations could include very fast-flowing waterways or close proximity to structures such as bridges, where it may be necessary to incorporate gabions and other engineered structures.

An example of this combination approach is when we need to use rock-filled gabions underwater to create a bank and have been able to improve their effectiveness, and prevent the erosion of back-filled soil, through the installation of willow spiling, and hessian and woven eotextiles.

Through many years of research and development, we have developed new – and highly effective - methods of installing live willow stakes in rocky river beds and fixing them back onto rocky banks. Willow can also be included to complement and soften the appearance of hard structures.

A typical composite solution is shown below. Severe erosion has cut a deep scour hole into the river bank and a stone-filled gabion is used to form a training wall below the water level. Willow branches protect the re-profiled upper bank and a pre-planted coir roll introduces new
marginal aquatic plants.

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