Siel und Schöpfwerk Knock, Floodgate in Emden, Germany

The Siel und Schöpfwerk Knock is a combined sluice and pumping station on the Knock in Emden's Wybelsum district. Two sluice gates, each 11.5 m wide, discharge half the rainwater, while four centrifugal pumps move 15,000 litres per second each. A 42-hectare Mahlbusen, a retention basin, sits beside the structure, which drains about 35,000 hectares via the Knockster Tief into the Ems.

The facility was built in the late 1960s and was the largest such system in Europe at that time. It was created to protect the region's flat land from flooding.

The facility shows how people in this region manage and control water as part of daily life. Visitors can see why such structures are essential when living in a landscape that sits partially below sea level.

Visitors can view the facility from outside and observe the sluice system structure. It helps to join a guided tour to understand how this complex technical system operates.

The facility includes a large retention basin that stores and slowly releases water. This basin itself is a noteworthy feature showing how engineers cleverly use the landscape for water control.