Chapter Summary

Multiple and varied factors contribute to the global increase in flooding. These include meteorological factors such as rainfall, storms and changing temperatures; hydrological factors such as soil moisture and groundwater levels; and societal factors such as changes in land use and occupation of floodplains. Floods in urban areas are an increasing concern as cities and towns expand rapidly, many along coastlines, where sea level rise and sinking land (or subsidence) compound risk.

Over the years, as flood risk has grown, the nature of that risk has changed. For example, although scientists cannot with certainty attribute a specific flood to climate change, they do know climate change contributes to extreme weather events. At the same time, policy-makers and practitioners have adopted a gradual but continual shift in policy and practice from flood control to flood risk management. The reason for this shift is that evidence confirms a narrow application of traditional engineering to control floods is not sufficient and is no longer appropriate as the sole approach to managing floods. Federal government policy requires all federal investments that affect floodplains to meet higher flood risk management standards and help conserve the natural values of floodplains. This policy establishes a new standard for flood risk reduction that reduces the risk and cost of future flood disasters, building on existing policy that "requires executive departments and agencies (agencies) to avoid, to the extent possible, the long- and short-term adverse impacts associated with the occupancy and modification of floodplains and to avoid direct or indirect support of floodplain development wherever there is a practicable alternative." [1]

Current better management practices for floods call for a holistic and integrated approach that engages multiple disciplines and experiences. Such an approach will build resilience and reduce vulnerability for both people and the environment. These improved practices also help planners understand and manage flood risk.

World Wildlife Fund (WWF), in partnership with the US Agency for International Development Office of Foreign Disaster Assistance (OFDA), has developed the Natural and Nature-Based Flood Management: A Green Guide (Flood Green Guide) to support communities at a local level in using natural and nature-based methods for flood risk management. An interdisciplinary global team developed the Flood Green Guide with a specific focus on advancing the development and application of natural and nature-based methods for managing flood risk.

The Flood Green Guide is based on collective experience, review and analysis of current and emerging flood management better practices, and on consultation with experts in engineering, water resource management, urban planning and policy, climate change, and community engagement and development. To develop the approach and content of the Flood Green Guide, the writing team also consulted with representatives from various communities in Asia and Latin America.

The Flood Green Guide draws from and complements existing resources and literature, and is based on the integrated flood management (IFM) approach, which recognizes that sometimes flooding is a natural and beneficial process. The Flood Green Guide is designed to maximize the benefits of floodwaters while offering guidance on managing and minimizing floods using natural and nature-based methods. We believe these methods are an important part of an integrated and strategic approach to flood risk management. As the Flood Green Guide is focused primarily on flood management methods, the guide is not designed to address every element of flood risk management. Additional resources are available to learn more about flood risk management. [2]

The guide is designed for those responsible for flood risk management, including municipal governments, community groups, and nongovernmental organizations (NGOs). The Flood Green Guide provides this audience with practical guidance and tools to understand the local context related to flood risk. At the same time, the Flood Green Guide describes a number of flood management methods that can be used in various combinations. Several case studies illustrate many of the issues and challenges related to flood risk management and how communities around the world are adapting and developing their own flood management methods. Every situation and community is different; the guide user will need to adapt the methods as appropriate for the local context and specific flood risk management objectives and acquire technical support as may be required.

The Flood Green Guide will be supported by a training program, and a website - - with a resource library containing additional information on innovative practices, case studies, and learning opportunities.


[1] Executive Order No. 13690, 80 FR 6425 (January 30, 2015).

[2] Paul Sayers et al., Flood Risk Management: A Strategic Approach (Paris: UNESCO, 2013).

Related Resources & Materials

Warning: mysqli_num_rows() expects parameter 1 to be mysqli_result, bool given in /home2/envirodm/public_html/flood-guide.php on line 209

Filling the knowledge gap between theory and practice

Crowdsourcing natural and nature based flood management methods from around the ...READ MORE

Guía Natural de Manejo de Inundaciones: Una Guía Verde

Ahora disponible la traducción en español del video de la Guía Verde para Inu...READ MORE

Harnessing Nature to Manage Rising Flood Risk

New framework bridges policy and practice outlining nature-based methods for flo...READ MORE

Cities are not islands, and why we need green flood management

WWF asks why aren't green methods used m...READ MORE

Flood Risk Management: A Strategic Approach

Book focused on strategic flood risk management policy and practice.READ MORE

Connect with Our Program