How does an FCA work?
A flood control area is an area adjacent to the river that is surrounded by a ring levee. This area serves as a water buffer zone in extreme weather conditions.
In an well-defined area, we build a high, sturdy ring levee inland, along the river. The existing river levee is then lowered and reinforced. The water can then flow over this overflow levee in the event of high water levels on the river. The ring levee protects the residential areas beyond it from flooding.
This creates a flood control area, which can store large amounts of water, along the river. The river’s water level is then reduced, which in turn relieves the pressure on the levees. The tidal wave loses a great deal of its force, and the risk of flooding or of a levee breach declines.
As soon as the water level in the river is sufficiently reduced, the water in the flood control area drains away through discharge sluices.
Generally speaking, a flood control area only occasionally fills with water. The rest of the time the area can have another function. Farmers can let their livestock graze in some flood control areas, while valuable nature can develop in others.