Bedload Experts Meet in Interlaken for an International Symposium

The international community of bedload specialists met in Interlaken in late 2021 to address current and future issues regarding the implementation of restoration measures in Switzerland.

Wasser-Agenda 21, a forum and network organisation for Swiss water stakeholders, organised the first International Symposium on Bedload Management which took place at the Lindner Grand Hotel Beau-Rivage in Interlaken from 8 to 10 November 2021. I interviewed the event organiser, Dr. Carlos R. Wyss, Project Manager at Wasser-Agenda 21, who gave insights into the event design process. 

About the organiser: Wasser-Agenda 21

The vision of Wasser-Agenda 21 is to provide environmental management goals and to support organisations by identifying, assessing and developing cross sectional topics. In Switzerland, there are many different organisations that try to defend their own interests in precious water resources. Wasser-Agenda 21 provides a platform for the stakeholders to meet and exchange about current and future water management challenges, aiming to provide solutions.

Wasser-Agenda 21 has two platforms dedicated to providing suitable structures for coordination and interdisciplinary dialogue: (1) hydro power refurbishment; and (2) river revitalisation. These two platforms offer opportunities for experts to network and exchange on experiences from practice. The platforms also process scientific findings and make them available to practitioners. One of the ways to achieve these goals is by hosting events.  

The International Symposium on Bedload Management was the first international event that was designed for the community dealing with this issue. Experts in the field of bedload management are mostly based in countries with mountain regions and face similar ecological challenges as those encountered in Switzerland. 

Event topic: bedload management – background

The topic, bedload management, was selected because it is a very current issue in Switzerland that concerns different stakeholders. Bedload refers to the particles (sand, cobbles and stones) that are transported along the stream bed. Hydropower installations can disrupt the continuity of bedload, while the water still finds its way downstream. The lack of bedload can have a significant ecomorphological impact below dams. A shortage of coarse grains can lead to the erosion of the riverbed, thus affecting the infrastructure along it. Gravel spawning fish (e.g., brown trout and grayling) and other animals (e.g., macroinvertebrates) are also dependent on fresh (without the accumulation of silt) bedload material. Additionally, the morphological structures that originate from bedload transport provide a variety of important habitats (birds, insects and plants) and may also serve as refuges for some species during floods.

One of the aims of the event was to address the lack of understanding in the field of bedload: first, in the complex restoration process of bedload budget for which little experience has been made and second, in the ecological impacts caused by a shortage of bedload material. In Switzerland, this topic is critical. In 2011, the Swiss Water Act was updated and under the new revision, all hydropower operators are obligated to refurbish their installations until 2030. This time frame led to a sense of urgency in holding this event and connecting all stakeholders.

Event objectives

The International Symposium on Bedload Management had the following objectives:

  • Create and review knowledge and praxis in bedload management 
  • Support the implementation of restoration measures in Switzerland
  • Strengthen the international network among scientists and practitioners

Faced with the challenges of bedload management in Switzerland, the goal was to support the implementation of bedload restorations measures which include planning, implementation and efficiency control. Switzerland has a legal goal and the financial tools to implement restoration measures in river stretches where the bedload deficit is caused by hydropower installations or retention basins. However, the dimensioning and implementation of these measures depend on the target state and the driving physical and ecological parameters for which there is currently little understanding.

It was also imperative to educate the stakeholders about efficiency control and its relevance: the success of the implemented measures hinges upon whether the restoration efforts result on the expected ecological improvements.   

Target audience 

The symposium was intended for people working within the area of bedload restoration and management. 

Stakeholder groups included:

  • Federal government 
  • Canton representatives
  • Municipalities
  • Employees in the water industry
  • Non-government organisations and associations 
  • Academia 
  • Professional bodies 

A total of 174 people took part in the event, including 54 online. 

Event format

The event consisted of the following format:

  • 3 days
  • 13 presentations in plenum simultaneously translated between German, French and English; offering translation was essential in order to encourage local stakeholders to take part
  • Social event 
  • 12 workshops 
  • 3 excursions to nearby valleys

Why were Interlaken and the Lindner Grand Hotel Beau-Rivage chosen for the event

There were two reasons for choosing to host the symposium at the Lindner Grand Hotel Beau-Rivage in Interlaken: 

  1. In 2016, Wasser Agenda 21 hosted a similar event in terms of duration and number of participants in Interlaken. The feedback from participants was very good so they decided to return. 
  2. There was a perfect fit between the destination, its proximity to sites where bedload restoration measures have been implemented, and the clusters of excellence, who were strongly connected. Participants could see active and pioneering restoration settings in Switzerland: how it looks and what can be expected from restoration measures. 

How did Interlaken Congress & Events support the event

Interlaken Congress & Events played a fundamental role in supporting the successful execution of this symposium. The main contact for coordinating the event was from Interlaken Congress & Events, and they served as the bridge between the hotel and the organisers in the lead up to the event. 

Side programme

  • The 12 workshops were designed to provide the participants with enhanced networking opportunities on specific subjects. The workshops were capped at 10 to 25 people to optimise the exchange of knowledge and networking between stakeholders. 
  • Excursions to the nearby valleys where restoration projects have taken place gave local and international participants an opportunity to witness the pioneering and successful implementation of bedload.  

Excursions: itinerary  

Excursion 1: Bedload management and restoration in the Aare headwaters Gadmer valley and Hasli valley (Canton Bern).

This excursion took the participants to the alpine headwaters of the Aare, where bedload transport is very dynamic and needs to be managed to protect populated areas and hydropower infrastructure. The execution started in the Gadmer valley, providing participants with opportunities to learn about the restoration of a large sediment retention basin, the morphological changes downstream and the influence of the residual flow regime on morphology and fish ecology.

Excursion 2: EcomorphologicaI effects of artificial floods in the Sarine floodplain (Canton Fribourg).

Starting at the dam at Rossens, the excursion began with a general introduction on the history of the dam, technical facts as well as river and floodplain ecomorphology in the context of residual flow management. A guided tour into the dam was provided by a hydropower company. The afternoon program continued downstream of the dam in the river floodplain at Hauterive where the ecomorphological effects of artificial flood releases were illustrated for the Sarine on site, in comparison with a long term artificial flood program at the Spöl river in Switzerland. Additional time was allocated for discussion.

Excursion 3: Sediment management at Spiez hydropower plant and river widenings at the Simme and Kander flood plains.

The rivers Simme and Kander are the big valley rivers of the western Berner Oberland. The morphological situation varies from channelised to natural structures, and parts of the rivers are used for hydropower, with effects on hydrology and bedload management. During the excursion, there was a presentation and discussion on measures for an improvement in bedload management (which had already been in progress for five years), as well as the ecological aspects of residual flow, artificial flow regime, floodplain ecology, lake trout and fish migration.

Online event component

The organisers worked with a local tech provider, ​​Graber Konferenztechnik GmbH, which was in charge of all technical aspects and which also had experience working with the hotel. 

Online audiences had access via Zoom, with the organiser using the platform’s following functionalities: 

  1. Simultaneous translation to other languages, which was a big asset for the audience and allowed them to choose their preferred language – German, French or English. 
  2. Networking features, which allowed attendees to exchange direct messages with each other during the Zoom ‘meeting’ format. 
  3. Opportunities for online participants to ask presenters questions in real time, which enriched the conversation. 
  4. Online streaming allowed remote speakers to give their talk virtually.

Significance for future research  

As the idea was to host an international symposium since its early inception, it was important for the organisers and members of the advisory board to create an event with findings and learnings that would be accessible to people who could not participate.  

To achieve this, organisers created a post-event document with extended abstracts. The articles (not peer reviewed) were reviewed by the members of the advisory board.

The proceedings were published online as an open access document in the ETH Zürich Research Collection, to share the content of the symposium with the global community. 

Furthermore, 12 small group workshops were held to discuss specific topics. In all the workshops, there was a person in charge of taking notes. It is intended to publish the discussion and results of selected workshops in the professional journal WEL (Wasser Energie Luft from Schweizerischer Wasserwirtschaftsverband (Swiss Association for Water Management), to circulate what was discussed in these workshops and allow access for those who attended other workshops. 

Sustainability initiatives at the event

Sustainable practices were incorporated into the event which:

  1. Encouraged attendees to take public transport to the location, which was achieved by sending dedicated emails to them with recommendations on how to arrive by train.
  2. Gave options for speakers from abroad to deliver their presentation virtually. 
  3. Reduced the travel time from venue to excursions, as Interlaken was a perfect location for this; organisers booked one bus for the attendees to travel together, removing the need to take individual transport. 
  4. Served exclusively plant-based food.


COVID-19 was the main challenge. It was difficult to decide whether the event should take place physically at all. At the time, government regulations allowed organisers to conduct live events limited to a certain number of people. Nevertheless, this remained a concern throughout the planning process. Despite the uncertainty surrounding COVID-19 regulations, the event was announced one year in advance and took place as planned.

Event objectives were achieved

Event organisers were very satisfied as the symposium successfully achieved all its objectives, including that of having every stakeholder present. Organisers were able to create a space for attendees to exchange knowledge and experiences about today’s restoration measures and address the future ecological challenges with respect to bedload transport.

The subject of bedload management is complex, and it is important to offer a platform for exchange on very specific aspects of it. This was achieved by presenting case studies and the latest tools, techniques and strategies to improve our understanding on the ecomorphological impact of bedload transport by improving the exchange between scientists and practitioners. 


The success of the event is due in large part to the establishment of an advisory board from the very beginning. The board consisted of experts representing the target audiences.

An event of this dimension is not required to take place yearly. A smaller event on this subject for Swiss stakeholders will take place in 2022, and an international symposium might be planned in a few years to reinforce the exchange of global practitioners in bedload management strategies. 


The International Symposium on Bedload Management demonstrated how to choose a destination that strongly aligns with the cluster of excellence and how the event experience can be enhanced by using the infrastructure and resources available at the destination. 

Bringing the bedload management community to meet face to face was crucial in order to address urgent matters, have intense conversations and exchange knowledge among all stakeholders. Having discussed very important issues, there was a need to retain and pass on this knowledge to those who could not participate at the event. Event proceedings are accessible online, and these are also significant for future research and events. 

Photo credits: Dr. Carlos R. Wyss

Header photo: Interlaken Congress & Events

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