Areas of Work
ENBE’s work applies in cases where man’s interests affect, or are affected by, the marine environment. Our work broadly falls into three areas: Coastal Management, Marine Structures and the Environment.
Coastal management is the implementation of an approach to work with the natural coastal environment to deliver a desired outcome. This may be undertaken through engineering means or by adapting to natural change. It is commonly required due to a need to protect land, infrastructure, property and important habitats from coastal erosion and flooding. In practice both threats usually apply to varying degrees depending on the circumstances.
A range of solutions are available to combat these threats, falling broadly into two categories – hard defences and soft defences. Hard defences include seawalls, revetments, breakwaters, artificial reefs, groynes and artificial headlands, whilst soft defences cover beach nourishment, beach management, managed retreat of a presently defended coast and in some cases simply letting nature take its course – otherwise known as “do nothing”.
Many of these solutions can also be applied to estuarine and fluvial environments. A scheme may comprise one or several measures encompassing both soft and hard defence measures.
As well as engineering studies and advice, our role will usually include environmental impact considerations (see Environment). We also advise on cost and economic criteria, constructability, planning and permitting.
Marine structures includes all the hard engineering structures listed under Coastal Management together with structures required for other applications including: breakwaters, quays, jetties, navigation channels and offshore structures for renewable energy schemes.
From an engineering viewpoint there are two main design criteria for every marine structure – it has to survive the marine environment in which it operates and it has to deliver the required function and performance. All marine structures interact with the marine environment and so the influence on hydrodynamic forces and the sediment regime must always be considered for every project.
Whether planning, designing or assessing marine structures we usually need to examine a range of technical considerations which might include: hydraulic performance (e.g. overtopping, run-up and reflection), structural stability, durability, longevity, geotechnical stability, maintenance requirements, operation and decommissioning.
Marine habitats such as rocky shores, sandy beaches, dunes, mudflats, salt-marshes, mangroves, brackish lagoons and coral reefs are essential components of the earth’s natural ecosystem. The appraisal of every project requires study and analysis of the impacts of a scheme on this environment. Interference from marine structures or natural causes for that matter, can have both immediate and long term implications locally and further afield. Impact considerations include the effects of: total loss (e.g. by scheme footprint), smothering of a habitat, changes to waves and currents, and changes to the sediment regime.
Central to these studies is the analysis of the hydrodynamics (wind, waves, water levels, tides and currents) and the effects of these processes on the sediment regime. Alongside the direct effects of a scheme, all such considerations must include the effects of climate change.
The appraisal of new schemes must always include consideration of the “do nothing” option. This essential part of the planning process examines what would happen if the proposed scheme, or indeed any intervention, were not to proceed. From an analytical standpoint this is essentially just another scheme but rather than examining the effects of the new project we examine the evolution of the shoreline, often subject to the deterioration of discontinued defence structures and, of course, climate change.