This website is under construction.


We are making lots of improvements and getting the new website ready for launch in September 2020!





International Network of Storm Surge Barriers

The I-STORM network brings together professionals that build, manage, operate and maintain Storm Surge Barriers. 

I-STORM aims to continuously improve standards of operation, management and performance in order to reduce the risk of severe flooding of people, property and places around the world, by facilitating knowledge exchange amongst members.

We aim to:

  • improve SSB operation, management and performance
  • inform concept, design and construction of new SSBs
  • optimise SSBs performance within Flood Risk System
  • understand impacts of environmental factors (such as the impacts of climate change including sea level rise) on SSBs
  • Collaborate on research and development

I-STORM shares knowledge and experience though a variety of activities:        

  • International peer reviews,
  • Working groups 
  • Technical knowledge exchange visits
  • Members Community of Practice area on our website
  • Newsletters

Annual Meeting 2016: I-STORM marks decade of knowledge sharing! 

Annual 2016 1

Storm Surge Barrier (SSB) professionals from the UK, Italy, USA, Belgium, Holland and Russia were amongst the 150 delegates at I-STORM’s 2016 Annual Meeting at the Eastern Scheldt Barrier in the Netherlands in October. The event provided an opportunity for colleagues to share their knowledge, be inspired and improve the performance of SSBs.



This year’s event marked the 30th anniversary of Eastern Scheldt and a decade of the I-STORM network. Delegates heard about the latest operations and developments at SSBs from around the world, and participated workshops ranging from: Sea Level Rise; Risk Based Asset Management; Peer Review; Knowledge Management and more, each designed to facilitate the sharing of expertise and assist future improvements.


Willy Dekker, Director of Network Management at the Rijkswaterstaat and I-STORM Strategic Board Chair said:  ‘I’m proud that the I-STORM network has grown in professionalism whilst remaining so open and hospitable. I’m confident that we’ve built a solid governance in which Core, Barrier and Associate Members can play their role in sharing their specialist knowledge on operating, managing and maintaining Storm Surge Barriers.


I saw many new initiatives between members, who shared interest and inspiration for further cooperation. I very much encourage this and hope you do whatever is needed to stimulate that kind of cooperation. ‘

Annual 2016 2 Annual 2016 3Annual 2016 4 Annual 2016 5


Annual Meeting presentations

Member’s can view and download presentations and the programme book for I-STORM Annual Meetings by first logging into member’s area.

  • 2016 Annual Meeting held in Holland, hosted by the Rijkswaterstaat at the Eastern Scheldt Barrier.
  • 2015 Annual Meeting held in Venice, hosted by the Venice Water Authority and Consorzio Venezia Nuova at MOSE.
  • 2014 Annual Meeting held in England, hosted by The Environment Agency at the Thames Barrier.


Interview: The Dutch are proud of feats of Hydraulic Engineering

Interview: 'The Dutch are proud of our feats of hydraulic engineering’

On Wednesday 3 January 2018, a severe storm caused water levels to rise all along the coast. For the first time ever, Rijkswaterstaat closed all 5 of the country’s storm surge barriers on the same day. Harold van Waveren, a senior adviser in Rijkswaterstaat’s Water division, looks back on this historic day.

The closed Maeslant storm surge barrier (archive photo)

Closure of 5 storm surge barriers

The high water level along the Dutch coast was caused by a storm that occurred during the night and early morning of 2 and 3 January as a front crossed the North Sea towards the north of Germany. A storm developed on the southern edge of the front. 'The wind picked up strongly in the early hours of the morning and only died down again towards the end of the evening. This caused water levels to rise,' Van Waveren explains. The higher water levels ultimately forced the closure of all 5 storm surge barriers. 'The storm surge barriers are designed to prevent water from reaching dangerous levels. The Maeslant storm surge barrier, for example, was closed when water reached 2.60 m above the Normal Amsterdam Level (NAP), in order to prevent the higher water from penetrating to Rotterdam. Of course the storm surge barrier could have been closed sooner, but we preferred not to because it would have had serious consequences for shipping and the port of Rotterdam and in terms of flood protection it was not necessary.'

Closure of storm surge barriers was essential

The question arose whether the storm surge barriers actually had to be closed. 'The barriers only close when the predetermined water levels (closure levels) are reached. These levels differ from one barrier to another and depend on factors such as the strength and direction of the wind and the length of time the wind persists. For the barriers in estuaries, the water level in the river can also be a factor. It was absolutely essential to close the Oosterschelde and Hollandse IJssel storm surge barriers and the inflatable dam, the Balgstuw Ramspol, because of the risk of flooding', says Van Waveren. 'A reduced closing level applied for the Maeslant and Hartel storm surge barriers. It is impossible to ascertain with certainty during a test how the barriers will work when they are closed during a storm. To discover that, they have to be closed during a storm once every seven to 10 years. This storm was therefore an important and successful test for the barriers, but was also a training opportunity for the team that closes them.'

'The Oosterschelde and Hollandse Ijssel storm surge barriers and the Balgstuw Ramspol had to be closed because of the risk of flooding.'

Harold van Waveren, senior adviser in Rijkswaterstaat's Water division

Close cooperation in the event of high water

'Rijkswaterstaat collaborates closely with the water boards when water levels are high. Together we protect the Netherlands against flooding', Van Waveren explains. 'During the storm we also communicated intensively with the port authorities of Rotterdam and Amsterdam and other stakeholders, including people living in areas outside the dykes.' The communication was not confined to the Netherlands: 'The locks at Terneuzen were shut on several occasions to allow excess water to be discharged so as to prevent flooding in Belgium.'

High water in the rivers

Although a lot of excess water is being discharged into the sea, there is still a huge volume of water arriving in the country from elsewhere in Europe via the rivers, which then have to discharge it. Can this cause problems? 'The water level in the Rhine and the Meuse is rising rapidly at the moment, but the rivers can handle it easily.' The floodplains of the rivers will be inundated, but that is what they are for. 'But even if the volume of water were to double – which is certainly not going to happen – there would be no flooding.'

Link to video: Closing of Maeslant storm surge Barrier (MPEG, 24,30MB)

Media reporting on closure of storm surge barriers

The new year storm received a lot of coverage in the media. Welcome attention, says Van Waveren. 'The media publicity for the storm surge barriers creates awareness of the crucial importance of flood protection in this country.' It also draws attention to the importance of the work done by Rijkswaterstaat and the water boards. 'The work we perform has enormous social relevance and its importance cannot be overstated. We also observe that Dutch people

News items

Can the UK learn from Dutch approach to living with water?

Marc Walraven, Storm Surge Barrier Senior Advisor at the Rijkswaterstaatand an I-STORM Delivery Board member has been interviewed by the ITV about the Dutch approach to managing flood risk. Link to ITV interview

Dutch Water Board share their key to success in engaging the community

Environment Agency colleagues have visited the Waterschap to learn more about the approach to temporary defences and engaging volunteers in Kampen, the Netherlands. Member link to presentation.

The two-day lifting test on Nov 28-29 2014 of 21 Mose sluice at Lido Nord. The 21 Gates staying on caissons in the bottom of the sea at the mouth of North Shore functioned exactly as it was intended.          

See the press release here


More Photos Venice test 21 sluices Nov 28-29 2014 Login required!


Newsletter 2015

Newsletter 2014

Newsletter February 2011

Newsletter October 2010

Newsletter December 2009

Newsletter May 2009


Select the latest news items. 

I-STORM conference 2013 in Venice

Last I-STORM Conference Venice 2013