Flood defence system construction: minimizing ecological and community impact

Thames Embankment

Flood Defences on the Thames: Ecological and Sustainable Engineering

The Thames River has a long a challenging history of providing both sustenance and representing peril to the Britons along its banks. London is an effective demonstration to the point, with its flood defence system among the most sophisticated in the world. For our purposes, it is well understood that the resources which are availed to London in the construction of its moveable flood wall are neither present nor appropriate in the case of the narrowing of the river in the proximity of Dartford Creek. However, it is here that the residents, construction and infrastructure in the vicinity are threatened both by the prospects of a decayed embankment and the inherent dangers to haphazard maintenance.

Therefore, as the village proceeds with an absolutely necessary plan for reclamation of its flood defences, civil engineering professionals must intervene to the benefit of the residents who will be most directly effected. Based on the information available to us, it is immediately apparent that the embankments which provide the primary bulwark for the city against the omnipresent threat of breach must be provided with the strength to withstand the pressure of storm surges that evidence suggests are increasing in intensity and frequency. With respect to the activity of the moveable flood wall parallel to London, all indications are that its movement over recent seasons has been gathering in necessity due to patterns attached to a trend of global warming.

There are ways for smaller villages to use this information to remain ahead of the curve. Here, we will aspire to build embankments engineered with a number of distinct features. Among them, the lesson learned from the success of London's flood prevention methods is that flexibility is a valuable virtue in the face of potentially catastrophic events, with the ability of flood defences to provide a relief through underflow, rather than overflow, in the face of mounting storm surges. This is an endeavor which will require engineers to adapt some of the principles in practice in more sophisticated flood walls, which are generally distributed astream rather than as embankments.

However, some engineering attributes will provide targets for engineers, who will recognize the core value of the ability of flood walls to rise and drop in response to factors indicative of an approaching threshold. Additionally, using heavily girded but hollow bodied and aerated bulwarks provides evidence of ways that such defences can be utilized as a way to relieve rather than build upon the pressures of a storm surge. Naturally, this will require no small degree of engineering ingenuity given the distinct challenge of adapting these principles to embankments, where redirection of underflow must naturally be more severely redirected than in the case of defence walls set astream as in the case of London.

A positive indicator as to the sustainability of this approach if adapted though is the 100-year life expectancy, even under currently projection intensification of storm surges, that is projected.