Our overarching philosophy is ‘designing with nature’.
Underpinning this is our application of the ‘process-based’ philosophy to river management. By first determining the ‘reference state’ for the river system, tackling the fundamental impacts to water and sediment supply/transport/storage at the largest possible spatial and temporal scale will begin a trajectory of recovery that is more natural, stable, self-sustaining and cost-efficient.
Our restoration approach is supported by the use of creative and innovative rehabilitation techniques that address complex hydrodynamic, geomorphic and ecological issues, often applied in conjunction with sustainable flood risk management (i.e. NFM) measures. cbec identifies implementable designs, which enhance ecosystem health and achieve water quality objectives while minimising flood risk and the need for future maintenance.
cbec offers support throughout the entire process of the implementation of a restoration project; from catchment-scale prioritisation to design optioneering/conceptualisation to detailed design development to construction supervision/management to post-works monitoring. Projects are supported through all of these stages by cbec’s expertise in fluvial geomorphology, hydrology, hydrodynamic/morphodynamic modelling, field data collection, design services, stakeholder engagement and construction management.
cbec applied an ‘assisted recovery’ design strategy to the River Nairn at Aberarder to provide the river with a greater potential for lateral movement, allowing it a better opportunity to adjust to a stable morphological condition. Designs included localised riparian reprofiling, a new 700 m long realigned course and, uniquely amongst UK restoration projects, the development of three ‘online’ wetland units. Construction of the river restoration designs was undertaken throughout summer 2017 and post-implementation monitoring began immediately.
Modelling of the constructed design has determined that the project has delivered a significant NFM benefit. Furthermore, within a few weeks of construction, Atlantic salmon were utilising the new sections of channel, having successfully negotiated passage through the new wetlands.