Extreme precipitation
We are all noticing that the climate is changing. Longer dry periods alternate with extreme rainfall. During the weekend of June 18-20, 2021, the northern part of North Holland was hit by two extreme storms within 24 hours. More than 100 mm of rain fell in an area measuring 50 by 10 km, with localised rainfall of up to 140 mm. A day later, another 40 to 60 mm of rain fell. This is unprecedented.
Because the predicted precipitation was still local and moderate until shortly before the storm, the intensity and extent of the storms and the subsequent disruption came as a surprise. In many places, the water in the watercourses rose to ground level and remained standing between the crops on the land. The flooding situation was most acute in Callantsoog, Zijpe, Sammerspolder, Baafjespolder, and Egmondermeer.
Together with farmers and contractors, the water board combated this nuisance. The amount of water meant that this took some time. The duration of this led to critical comments about the water board's responsiveness and the capacity of the water system.
Evaluation of nuisance control
The water board took and continues to take these comments seriously. After every crisis situation, we evaluate the events and the approach taken. These storms were so extreme, and the impact in our working area was so great, that we opted for a comprehensive approach. This was partly motivated by the knowledge that the likelihood of this type of extreme precipitation will increase as a result of climate change.
The purpose of the evaluation was to answer the following questions: How was the flood control operation carried out, what went well, and what could be improved? The evaluation was conducted by the HHNK civil service, assisted by three external specialists. The evaluation looked at data from the telemetry system, information from logbooks and situation reports, interviews with those involved in the field service and the crisis management organization (CBO), and input from the surrounding area, such as the agricultural sector and municipalities. The evaluation report can be found here:
What will happen to the water board now?
Management during crisis situations will become an increasingly important part of everyday water management. The water board must adapt to this. The recommendations of the evaluation of the flooding in June 2021 therefore do not call for 'stepping up flood control efforts' but for a broad approach within the water board. This approach focuses on risks in the areas of flooding, drought, and water quality, including the reliability of information and control systems that form the lifeline of any crisis management. We are committed to rapid and thorough improvement, bringing in external expertise and strengthening our own people and organization. In this way, we are also breaking down the barriers between internal and external services and between the water board, residents, and crisis partners.
Board
Our general board met in an extraordinary meeting on June 23, 2021. You canwatch themeeting at. This presentation was given to the board during the meeting.
During this board meeting, it was agreed that the general board would be kept informed of progress. On August 2, 2021, this progress memo was sent to the general board. This memo provides further details on the evaluation team's working methods and areas of investigation.
On Wednesday, October 27, 2021, the general board met to discuss the flooding and its aftermath. You can watch a recording of the meeting at .
A resilient organization
In December 2021, we launched theCrisis Management in the Genes (CING) programme . This programme the recommendations of the evaluation and focuses on making employees, residents, and the water system more resilient to these types of extreme rainfall events.
