Cities and industry
Keeping the Netherlands dry
Giant pumping stations lift rain and river water over the dykes, day and night.
- Land below sea level
- about a quarter of the country
- Wouda pumping station (1920)
- about 4 million litres per minute
- IJmuiden pumping station
- about 260 m³ per second
- Head
- only a few metres
Numbers are rounded, typical values — real machines vary.
Why pumps and not just ditches
A large part of the Netherlands lies below sea level. Rain that falls there can’t flow away by itself, so it is collected in ditches and canals and lifted over the dykes into rivers and the sea.
Windmills did this for centuries. Today it is done by pumping stations with some of the largest pumps in the world.
Huge flow, tiny lift
The water only needs to rise a few metres, but the amount is enormous. That is the textbook job for and impellers — big propeller-like rotors in wide pipes.
The historic steam-driven Wouda pumping station, now a UNESCO World Heritage site, can still move about 4 million litres every minute when needed.
Physics you already know
Low head and very high flow means a very high . The shifts with the sea level outside: at high tide the pumps must lift higher and deliver less.