Polder south of Amsterdam becomes emergency flood overflow area

The water board (waterschap) Amstel, Gooi en Vecht has completed an inlet structure along the Amstel, making polder De Ronde Hoep in Ouder-Amstel an emergency overflow area. As a last resort, the sluices would be opened and up to 2.4 billion litres of water would flow into the polder.

The aim is to prevent about 1.4 million residents of Amsterdam and surrounding municipalities from being flooded. The province of Noord-Holland instructed the water board to create the overflow area.

Only when all other measures prove insufficient can the safety region decide to flood the polder, which covers more than 600 hectares. Board member Arjan van Rijn said that would happen only under a very exceptional combination of circumstances, such as extreme rainfall, a particular wind direction and high water levels at sea, in the IJmeer and in the Markermeer.

The water board has already set up a compensation scheme for residents, most of them farmers. It pays full compensation for damage to houses or barns, pays farmers for lost milk income and covers protective measures to prevent damage.

“We hope never to have to use this site,” Van Rijn said at the handover. “Flood safety also means thinking ahead. Based on what we know now, we should never need this emergency overflow area. But we might have to use this polder once in a hundred years, as a last resort.”