Floodplain Permit

The construction of structures in the floodplain is prohibited under Section 78 (4) of the Federal Water Act (WHG).

According to Section 78a (1) WHG, the construction of walls, embankments or similar structures, the handling of substances hazardous to water, the depositing of objects, the raising and deepening of the earth's surface, the planting of trees and shrubs, and the conversion of grassland and alluvial forest are also generally prohibited.

Under certain conditions, an exemption may be granted by the lower water authority.

Information on the delimitation of the floodplains and on the predicted water levels in the event of a statistically recurring flood HQ(100) every 100 years can be obtained from the lower water authority.

The following documents must be attached to the informal application and submitted in duplicate in paper form to the lower water authority:

• Explanation of the project
• General site plan M 1 : 25 000 or M 1 : 10 000
• Site plan
• Excerpt from cadastral map
• Construction plans/ detailed plans
• Proof of retention area compensation (base area x water level)

• Federal Water Act (WHG)