The map that shows the so-called flood zones is called a flood map and is used by insurance companies as one of the sources for calculating and pricing premiums for home and property insurance. They assess the risk of flooding in a given area and then reflect the rate in the insurance premiums.
The determination of the flood zone is influenced by the characteristics of the terrain and the presence of permanent flood barriers.
- Flood Zone 1 covers an area with negligible risk of flooding, and does not increase premiums.
- Flood Zone 2 refers to an area with low flood risk, premiums may increase.
- Flood Zone 3 represents a medium risk of flooding and either the premium will be increased significantly or the land and property cannot be insured.
- Flood zone 4 says that the area is at high risk of flooding and the house is difficult or impossible to insure.
The flood map divides the area into 4 flood zones
You may also encounter the term floodplain, which is determined by the water authority by hydraulically calculating the highest water levels for flows with different return periods. The active flood zone is determined by the preparation of flood hazard maps according to the flood flow hazard. These are areas determined by a measure of a general nature which may be inundated by water during a natural flood.