Managing aquatic environments and flood prevention: Irstea at the service of the GEMAPI

Can you remind us what GEMAPI is and what it will change for the communities that have to implement them?

Freddy Rey: GEMAPI is really a regional “super-responsibility.” It groups together responsibilities relating to the management of aquatic environments and flood prevention that were previously separate and managed by distinct organizations. From now on, GEMAPI will involve a single legal entity: municipal groups in this instance and by automatic transfer, groups of Communes with a Common Developmental Purpose or Project (EPCI) with their own tax status [1], responsible for managing an entire river basin. It is an important step in joining two facets of water management that are each the result of a European directive (European Water Framework Directive) with, until now, their own national implementation and management plant (SDAGE - Management Plan for Water Development and Management and PGRI - Flood Risk Management Plan). An integrated approach is essential, but complicated to implement as river basin boundaries do not correspond to their municipal counterparts.

Cerema and Irstea launched a call for partners from municipalities in May 2016, offering to support them with their new responsibilities. What exactly is the aim of this partnership and how far has it developed?

Freddy Rey: Given our complementary skills and previous partnerships, our two organizations are particularly well suited to supporting municipalities with their new responsibilities. The aim of the call for partners was to let them know and to offer those who might be interested some management, engineering or governance help on a river basin scale. Our support is unique because it is built on the innovative nature of our tools and methods; we provide new approaches based on experiments performed as part of our research.

The result of the call for partners was a contract to help nine municipalities representative of the country as a whole (including mountain and coastal regions). Irstea is involved in several of these partnerships: Joint association for the inter-community management of Buëch and its tributaries, Troyes Champagne Métropole, and soon, the Alsace-Moselle Water and Sanitation Association.

In addition to the ongoing support, this partnership process will result in a national level assessment during 2018. The aim is to capitalize on each lesson learned to tease out solutions that can be transferred to other contexts and regions. Using guides, methodologies and other supporting materials posted on the dedicated internet site as they become available, all municipalities within the region will be able to benefit from the lessons learned from these specific experiences.

How will Irstea support, now and in the future, these municipalities, within the partnership framework or independently?

Freddy Rey: Our support basically involves applying the methods we have developed to perform ecological diagnostics in the environment, evaluate flood protection structure performances and perform multicriteria[2] and cost-benefit[3] analyses. Our tools make it possible to go from initial diagnosis to possible intervention methods, while also including socioeconomic assessments for any action considered.

For example: the legislation implementing GEMAPI defines new concepts such as the “diking systems.” It is no longer enough to look at dikes individually, they must be considered as part of a network of structures that are involved in protecting against floods. In itself, the new concept requires support for municipalities who have to define their diking system and evaluate its effectiveness. Another example: planning integrated river basin management means that flood prevention is not only based on diking systems but also on the ecological characteristics of the river basin itself. At Irstea, we study the interactions between structures (flood expansion areas, dikes, etc.), plant cover and flood and high water processes across river basins. Therefore, these are processes for which we can provide support.

How do you explain the quasi-natural position of a research institute such as Irstea on the questions raised by GEMAPI?

Freddy Rey: Because of the very nature of our research, part of which deals with water and stretches from the very broad to the very focused, as well as our expertise on issues of regional management. Also because of our history of providing research to support public policy and decision-makers, specifically in relation to environmental issues and natural hazards.

Furthermore, Irstea brings together specialists in dikes, flood and high water phenomena and environmental and ecological rehabilitation. This diversity, our multidisciplinary nature and our historical involvement in an integrated vision of water management means we are in a strong position to meet the challenges of integrating the management of aquatic environments with flood prevention. Although we have a head start in some areas, we are lacking in others; GEMAPI will allow us to redirect our research towards the integrated approach that is so essential to managing water and preserving biodiversity (for example, by reinforcing an interdisciplinary approach between ecology and geosciences, or ecology and human and social sciences).

For more information

[1] Municipality groups, town groups, urban and metropolitan groups.

[2] "Multicriteria" analysis generally means a group of methods used to aggregate several criteria in order to select one or more actions, help with diagnostics and, more generally, support strategic and operational decision-making. Source Ministry of Economics and Finances

[3] A cost-benefit analysis is defined as an assessment of the costs and resulting benefits prior to investment or policy change, expressed in monetary terms. Source Ministry of Economics and Finances

Consult the web page of the Cerema-Irstea call for partners