EWOOE

  1.    Context

Overflowing erosion of embankment dams and levees, overflowing erosion of bedrock downstream of concrete dams (through crest overtopping or spillway flow impact) and overtopping erosion of embankment dams and levees (in particular coastal levees) are of major concern for dam owners and asset managers. Every year, several large embankment dams (according to the ICOLD definition of a large dam) and tens of small embankment dams and fluvial levees fail in the world due to overflowing erosion. These hazards should be reanalyzed in the light of the reassessment of the consequences of climate change on hydrology, and the assessment of floods, leading to unplanned overflows during the design phase. The unexpected 2017 damage at Oroville dam, in USA, reminds us all that energy dissipation and erosion of downstream spillways and flow control equipment can also be the cause of major risks, with huge potential social and economic consequences. The forecast of sea level rise during the upcoming decades points out the issue of the increasing risk of sea levee failure by overtopping. The large uncertainty in the quantification of sea level rise and its impact on the intensity of extreme events complicates the determination of hydraulic boundary conditions.

The state of art still need to improve in order to build and maintain safe and sustainable hydraulic structures and to face the risks caused by overflowing and overtopping erosion.

In December 2017, EDF organized in Aussois, France, on behalf of the French Committee of Large Dams (CFBR) and the European Club of ICOLD (EURCOLD), a workshop dedicated to presenting and discussing the owners’ issues, the current practices of consulting engineers, the progress of research and the gaps which need to be filled. As the feed-back from the 65 professionals coming from 15 countries who attended this workshop showed that this initiative was useful, and pointed out the need to improve international collaboration in this field, it was decided to launch a new European Working Group on Overflowing and Overtopping Erosion (IWGOOE), hosted by EURCOLD.

2.    General objectives of the working group

The general objective of this working group is to help reduce the risk of failure of hydraulic structures, and the associated consequences, by overflowing and overtopping erosion all over the world. This general objective can be defined according to the following items:

-    Sharing issues and problems to solve exposed by dam and levee owners, in all locations and load conditions (i.e. inland, fluvial and coastal);

-    Sharing current state of practice and gaps in the toolbox available to practicing engineers;

-    Sharing progress and advances from academic research and helping to pilot this research from the practitioner’s perspectives and needs;

-    Sharing the state of the art of the protection technology in order to increase the safety of dams and levees in overtopping scenarios;

-    Facilitating international research collaboration to speed-up research progress and help dissemination of results.

Although this working group is hosted by the European Club of ICOLD, it is open to owners, flood risk managers, consulting engineers and academic researchers from all over the world. Dissemination of knowledge and the most recent results of research to practitioners from developing countries is also an important objective of this working group.

3.    Structure

This working group is structured into 4 sub-groups:

•    Sub-group 1 is dedicated to overflowing erosion of embankment dams and levees;

•    Sub-group 2 is dedicated to overflowing erosion of bedrock downstream of concrete dams and overflowing erosion of spillways;

•    Sub-group 3 is dedicated to overtopping erosion of levees;

•    Sub-group 4 is dedicated to protection technologies against overflowing erosion of dams and levees.

The IWGOOE is chaired by Jean-Robert Courivaud, embankment dam expert at the EDF Hydro Engineering Centre, France (jean-robert.courivaud@edf.fr).

Each sub-group is led by two co-chairmen.

Sub-group 1 is co-chaired by: -    Stéphane Bonelli, Researcher at IRSTEA, France (stephane.bonelli@irstea.fr); -    Mark Morris, Hydraulic expert at HR Wallingford and SAMUI, UK, France (mark.morris@samui.co.uk);

Sub-group 2 is co-chaired by: -    Frédéric Laugier, Dam safety expert at the EDF Hydro Engineering Centre, France (frederic.laugier@edf.fr); -    Mike George, Senior geological engineer, BGC Engineering, USA (mgeorge@bgcengineering.ca);

Sub-group 3 is co-chaired by: -    Myron Van Damme, Researcher at Delft University of Technology, The Netherlands (M.vanDamme@tudelft.nl); -    Tim Pullen, Sea levees Expert at HR Wallingford, UK (t.pullen@hrwallingford.com);

Sub-group 4 is co-chaired by: -    Miguel Ángel Toledo, Professor at UPM, Spain (miguelangel.toledo@upm.es); -    Rafael Moran, Professor at UPM, Spain (r.moran@upm.es).

4.    Organization

The IWGOOE will meet periodically every two years through the Protections Conference series. Protections Conference series were initiated prior to this working group. They have already been organized three times: firstly, in Madrid in 2014, secondly in Fort Collins (USA) in 2016 and thirdly in Grange-over-Sands (UK) in 2018.

As the scope of this conference was very similar to these ToR for the IWGOOE, it made sense that this conference becomes the periodic meeting of the IWGOOE. 

Attendance to this conference will be open to all professionals interested in this field. The communications presented during the conference will be structured according to the 4 sub-groups constituting the IWGOOE.

Attendance to the IWGOOE is free. However, attendance to the periodic meetings (i.e. Protection Conferences) will cost fees defined by each organization in charge of the conference organization, in addition to the associated travel and accommodation costs.

People interested in promoting projects, international collaboration, etc. through the IWGOOE can contact directly Jean-Robert Courivaud and the chairmen of the dedicated sub-groups directly.