What better place to explore coastal resilience than New Orleans? And what better occasion than a three-day conference organised by the US Army Corps of Engineers? Lucky me.

Amongst the diversity and detail of the conference presentations, there were four cross-cutting ideas that, for me, came into sharpest resolution. Interestingly (and perhaps reassuringly), these resonate with some of the themes highlighted by our ‘resilience project’ Working Group when they met last month. While the conference focused on coastal systems (hubs of population, economic activity and critical ecosystems, and so ideal resilience microcosms), the key issues that emerged would apply to the resilience of other systems too.

So here goes: three days rolled into four concepts and one blog post…


1) Coastal resilience requires a SYSTEMS APPROACH: a portfolio of interventions to deliver a full array of benefits. Several metaphors to this effect flew around the conference room, from ‘there’s no silver bullet’ to ‘every resilience intervention is simply one arrow in your quiver’. It was widely agreed that a resilient system should comprise complementary but independent components, with built-in redundancy to reduce the risk of catastrophic failure.

To make this idea a little more concrete (no pun intended!), a suite of physical interventions was discussed; some better suited to particular shocks or stresses than others. For instance, engineered solutions (dams, levees etc.) will continue to be necessary for major, intensive events – the Katrinas and Ritas of this world. But nature-based approaches (wetlands, dunes etc.) can also to temper these events, while simultaneously reducing the impact of the less-headline-grabbing extensive events, which can erode people’s resilience just as much.

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So far so good. But what about the practicalities? Well, in order to actually deploy a portfolio of interventions (like the multiple lines of defence above), synergies should be sought to get the job done more affordably. A Louisiana example of this came courtesy of the dredging community, who have long worked to maintain navigation channels, but who now offer up their precious sediment by-product for beach nourishment, dune building, and wetland restoration projects. Across the pond, a striking UK example came in the form of Wallasea Island, where resilient intertidal habitat has been established using excavated soil from the Crossrail project.

But there’s more! Even where an affordable portfolio of physical interventions can be delivered, it will only be effective at building resilience if underpinned by a robust social and institutional infrastructure (another can of worms for another blog post…).

In other words, adopting a systems approach is no mean feat.


2) NATURE-BASED APPROACHES to building resilience are gaining traction – and with them, engineered/nature hybrids. The US Army Corps of Engineers, for one, have adopted an ‘Engineering With Nature philosophy, defined as ‘the intentional alignment of natural and engineering processes to efficiently and sustainably deliver economic, environmental and social benefits through collaborative processes’. It’s a shift that, for some, demands a certain degree of ‘un-learning’ of the traditional tenets of engineering.

But challenges remain. There’s still considerably more evidence associated with engineered solutions than nature-based ones. The former are tried, tested, and therefore trusted. As for the latter, there is admittedly a growing body of evidence demonstrating the risk reduction properties of ecosystems (eg. this compelling case). Yet, in general, the oft-cited co-benefits of nature-based solutions (biodiversity conservation, climate change mitigation, community engagement…) are too often assumed rather than proven. The result? Implementation based on faith rather than evidence.


3) Enduring resilience requires large geographical and temporal SCALES. On the geographical front, one conference delegate presented a powerful example (below) of how historical UK administrative boundaries once led to irrational and inconsistent coastal management: a stark reminder of the need for strategic, national (or at least large-scale) land and marine planning. On the bright side, the US’s Climate Science Centers and Landscape Conservation Cooperatives were offered as good examples of planning units that operate across administrative boundaries.

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On the temporal front, many agreed that what’s needed are timescales that are not only long enough (far exceeding those associated with funding and political cycles), but that also extend far enough into the future. Despite the status quo for reactive investment after a major disaster, anticipatory interventions are needed in order to ‘get ahead of the disaster curve’ and avoid maladaptation further down the line.


4) Coastal resilience is an ongoing PROCESS – not a static state – in which risks and opportunities are identified and prioritised, risk reduction measures implemented, and their effectiveness reviewed through monitoring and evaluation (as outlined below, from this excellent overview).










While the theory’s all well and good, there remains a lack of long-term monitoring for many resilience projects; and too often an insufficient scientific understanding of the coastal system in question. Both forms of evidence are prerequisites for the sorts of decision-making that are most likely to foster successful adaptation and long-term resilience.


So all-in-all a fascinating three days, highlighting above all else that coastal resilience is a fiendishly difficult concept to put into practice. But in doing so – in picking the right combination of bullets and arrows, and the right system and processes to embed them in – practitioners and decision-makers alike should be guided by the best available evidence, and not the ‘slings and arrows of outrageous fortune’.