Extreme precipitation
We all notice that the climate is changing. Longer dry periods alternate with extreme rain showers. During the weekend of June 18-20, 2021, Hollands Noorderkwartier was hit by two extreme showers within 24 hours. In an area of 50 by 10 km more than 100 mm and locally as much as 140 mm fell. A day later another 40 to 60 mm was added. Unprecedented to date.
Because the predicted precipitation was still local and moderate until shortly before the downpour, the intensity and magnitude of the showers and subsequent nuisance came as a surprise. In many places, water in the watercourses rose to ground level and water remained between crops on the land. The waterlogging situation was most acute in Callantsoog, the Zijpe, the Sammerspolder, the Baafjespolder and the Egmondermeer.
Together with farmers and contractors, the Water Board fought this nuisance. The volume of water made this take time. Its duration led to critical comments about the water board's responsiveness and the capacity of the water system.
Nuisance abatement evaluation
The Water Board took and takes these comments seriously. After every crisis situation, we evaluate the events and the approach. These showers were so extreme, and the impact in our operating area was so great, that we chose to take a comprehensive approach. This was prompted in part by the knowledge that the likelihood of this type of extreme precipitation will increase due to climate change.
The purpose of the evaluation was to answer the questions: How did the flood control go, what went well, and what could be improved? The evaluation was carried out by HHNK's administrative department, assisted by three external specialists. Data from the telemetry system, information from logbooks and situation reports, interviews with those involved from the field service and the crisis management organization (CBO) and input from the surrounding area such as the agricultural sector and municipalities were considered. The evaluation report can be found here:
How does the Water Board move forward?
Management during crisis situations will become an increasing part of everyday water management. The State Water Board must adapt to this. As such, the recommendations of the June 2021 flood assessment do not call for "stepping up a gear in flood control" but for a comprehensive approach within the Water Board. This approach focuses on flood, drought and water quality risks, including the reliability of information and control systems that are the lifeblood of any crisis management. We are committed to a rapid and thorough improvement effort, bringing in external knowledge and strengthening our own people and organization. In this way we also break down the barriers between the internal and external departments and those between the Water Board, residents and crisis partners.
Board
Our General Board met in an adjourned meeting on June 23, 2021. You can review the meeting . The meeting included this presentation to the board.
During this board meeting, it was promised 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 details the evaluation team's methods and areas of investigation.
On Wednesday, Oct. 27, 2021, the General Board met to discuss flooding and its aftermath. You can review the meeting .
A resilient organization
As of December 2021, we have launched the Crisis Management in the Genes (CING) program. This program picks up the recommendations of the evaluation and focuses on making employees, residents and the water system more resilient to these types of extreme rainstorms.
