Natural buffers: managing wetlands for flood resilience

Contributor: Will Bugler

For years communities across the world have suffered the devastating effects of flooding. It is likely that climate change is increasing the frequency and severity of many of these flood events, and population growth – especially in coastal cities – is putting more people in harms’ way. The instinctive response to increased flood risk is often to call in the engineers and build flood defences. However, a new book calls into question this model for managing flood risk, suggesting that is ineffective, and that it is based on an out-dated model of assessing climate risk.

The 43-page book, “Downstream Voices”, commissioned by Wetlands International and written by Fred Pearce (news editor at the New Scientist), takes the reader on a journey to three large river basins in India, Mali and Senegal where Wetlands International improves water resource management and the condition of wetlands to make communities more resilient to extreme weather events and impacts of climate change.

Pearce challenges the dominant notion that taking action to reduce climate risk requires ever-more complex climate models, at ever-greater resolutions, powered by ever-larger computers. “Some generalities emerging from the models may hold.” Pearce writes, “But there is a growing realisation that we will never know in any detail what is coming down the track.”

His argument holds that at the local level the uncertainties around climate change will always to great to adapt to a specific climate impact and that instead, we should plan for greater uncertainty.

Instead, Pearce advocates a resilience approach, one that accounts also for the complexities of systemic, non-climate related factors that interact and contribute to flood vulnerability. “Climate risks, though pervasive, are just one of a suite of challenges facing poor communities in particular “in a complex and changing world,” he writes.

The book presents the case for ecosystem-based solutions to flood risks and provides some valuable insights and examples of how an ecosystem approach to disaster risk reduction is working on the ground in India, Mali, Senegal, the Philippines and Kenya.

Ecosystem management for disaster resilience

Many of the stories result from an innovative, five-year programme called ‘Partners for Resilience’. The programme integrated ecosystem management into disaster aid work and remains the biggest of its kind in the world.

One of the sites discussed is the Indian coastal state of Odisha, which was hit by tropical cyclone Phailin in 2013. While India successfully evacuated nearly a million people from the coastline, the village stayed flooded long after the cyclone. Embankments prevented the water from receding and the river was clogged with silt as a result of soil erosion.

By shifting the focus away from impact-specific adaptation measures, the project sought to strengthen the natural ecosystems that can protect the region. The project encouraged villagers to collaborate to re-vegetate riverbanks, align cropping patterns with the floods, and de-silt the river mouth. Additionally, at delta level, Wetlands International is advising on how to realign operational regimes of the upstream Hirakud Reservoir, a hydropower structure that influences fluvial regimes of the delta.

The results of the project will not be to eliminate the risk of flooding. Instead, the focus is on reducing the risk of flooding causing harm. “Communities that once lived with floods, benefitting from the fertile silt that they distributed across the delta, now live behind embankments.” Pearce writes. “They are dependent on artificial fertiliser to replace the silt, and are increasingly vulnerable to major floods that can breach the defences.”

The project has found that the best adaptation measures for the local community are those that allow the villages to live with, rather than prevent the floods. The result will usually be soft engineering, which nurtures rather than confronts natural processes.

“During my journey, I witnessed the challenges that vulnerable rural communities face in relation to environmental hazards”, says Pearce, “Few people realise the extent to which increased risk is caused or exacerbated by mismanagement of land and water resources, sometimes far away in the landscape”.

A copy of the book, ‘Downstream Voices’ can be downloaded here.

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