Updated surface runoff hazard map
The Surface Runoff Hazard Map (GOA) has become one of the most important tools for the prevention of natural hazard damage. It supports the cantonal building insurers as well as private insurers and also serves as a planning aid for flood protection projects and in settlement drainage. Based on new data sources and improved modelling capabilities, the map is currently being comprehensively updated and will be published in a new version at the beginning of 2027.
Over the past decades, building damage caused by natural hazards has more than doubled. Flooding accounts
for a significant share of the total damage. Rising insured values, changing building vulnerability and the increasing sealing of the ground all contribute substantially to the increase in building damage. More than half of all flood damage is not caused by rivers, streams and lakes overflowing their banks, but by surface runoff.
To reduce or even prevent damage caused by flooding, buildings should
be constructed and maintained to be as weather-resistant and damage-proof as possible. First, however, the hazard posed by surface runoff must be known in order to implement protective measures p>
Key instrument for preventing flood damage
The GOA shows, across Switzerland
, possible flow paths and flood areas during heavy rainfall. Since its publication in 2018, it has become an indispensable tool for prevention. The hazard map thus closes an important gap in this field.
New data foundations enable a comprehensive update
The Surface Runoff
Hazard Map was created in 2018 on the basis of the information and technologies available at the time. Since then, the data foundations for precipitation, the terrain model and land cover, as well as the methodology for modelling surface runoff, have improved – also thanks to the steadily increasing computing power of computers. For this reason, the hazard map is being re-modelled and updated this year. At the beginning of 2027, it will be available free of charge and will replace the previous surface runoff hazard map.
The project is once again being implemented through collaboration between the Federal Office for the Environment (FOEN), the Swiss Insurance Association (SIA) and the Association of Cantonal Building Insurers (ACBI), and is financed by the SIA and the ACBI. >
In natural hazard prevention, raising public awareness is crucial. The update of the hazard map is
therefore accompanied by various short videos. These explain surface runoff and the hazard map and provide information about the hazard for buildings. The videos will be released in stages and can be accessed on a landing page created specifically for surface runoff on the information platform “Protection from Natural Hazards”.
To the landing page:
www.schutz-vor-naturgefahren.ch/goa
For media inquiries:
Diego Meuli, Media spokesperson and topic manager, Swiss
Insurance Association SVV,
T 044 208 28 16, diego.meuli@svv.ch
Rolf Meier, Head of Communications, Association of Cantonal Building Ins
urers VKG,
T 031 320 22 82, rolf.meier@vkg.chp>