About this map
Six centuries of pumping the Netherlands dry, and of the floods that came anyway. Orange patches are fields of polder windmills: the darker, the more mills per 100 km². Every small dot is a pumping station, in the year it was founded: red for steam, purple for diesel and gas, teal for electric, grey where the register does not say. Green areas are lakes and peat pits pumped dry (droogmakerijen), in three shades for the windmill era, the steam era and the electric era. Grey is the water of the time, so the coast and the lakes you see are those of that year. Blue pins are floods and high water, dark pins the machines, green and brown pins the drainages and dikes. The bar at the top counts polder windmills standing against pumping stations founded. What it shows: wind kept the west dry from the 15th century. By 1700, 1,196 polder windmills are on record, most of them in Holland and Utrecht. The cadastre of 1832 gives the first nationwide picture: 4,242 polder windmills. 2,691 of them, nearly nine in ten in Friesland and most of them small, enter the record only then. About 1,000 are gone from the record again by 1850; with new building the number returns to 3,947 around 1880. Steam was tried from 1776 but took off only after the Haarlemmermeer (1852): 398 steam stations are on record, 232 of them founded in the 1870s and 1880s and 262 in Noord- and Zuid-Holland. The small mills of the north held out until diesel and electricity arrived: between 1920 and 1932 the number of polder windmills standing fell from 3,186 to 960. By 1939 more pumping stations had been founded than polder windmills were left; today 417 complete polder windmills stand, about a tenth of the number around 1880. Scale changed with the power source. In the lakes drained in the windmill era the heritage agency records one mill for about every 120 hectares; the Haarlemmermeer (182 km²) was emptied by three steam stations and the Noordoostpolder (480 km²) is kept dry by three diesel and electric ones. Lakes drained up to 1830 add up to about 607 km² (142 droogmakerijen), those of the steam era (1830–1918) to 664 km² (86), and those since 1918 to 1,709 km² (17, mostly the IJsselmeer polders). Do floods bring pumps? In Zeeland 23 pumping stations were founded in the ten years after the flood of 1953, against 4 in the ten years before; in the rest of the country the number went from 72 to 133. The Zuiderzee flood of 1916 and the river flood of 1926 left no such mark: Noord-Holland went from 11 to 19 (rest of the country 55 to 99), and Gelderland, Noord-Brabant and Limburg from 12 to 28 (rest 106 to 160). That is an indication, not proof: the numbers are small, the war years lower the count before 1953, and the register is incomplete. After 1953 the flood pins are of another kind: a near-miss on the rivers (1995), a rain flood (2021) and a peat dike that failed in a drought (2003). How to read it, and the limits. Mills: polder windmills from the register of vanished mills (molendatabase.org, De Hollandsche Molen) and the register of existing mills, both published by the Cultural Heritage Agency (RCE). A mill counts from its year of building to the year it disappeared. Many of those years are really the first or last map or survey on which a mill appears: the dates pile up at 1832, 1850, 1873–1883 and 1924–1930. So mills appear and vanish in steps at those dates, and the collapse of the 1920s is drawn at the end of the period in which it happened. Before 1832 the north is under-recorded, not empty: the lilac wash marks the area where mills are on record only from 1832, and the bar shows the possible range. Left out: 867 vanished polder mills without usable dates and 112 surviving stumps; 138 existing mills without a recorded year of building are counted from 1900. Industrial and corn mills are not shown. Pumping stations: 2,228 stations with a founding year from the register of the Nederlandse Gemalenstichting (via RCE), which is strong on historic stations but is not a complete list of today's; 435 without a year are left out. A dot keeps the colour of the power it was built for and stays on the map: the register has no closing dates, though many steam stations were later converted or demolished (hover for today's state). Drained lakes: the RCE droogmakerijen layer after the NAi Polder Atlas, each shown from the first frame at or after its year of drainage; 23 early polders dated only 'before 1550' appear in 1570. Breach ponds: the 1,266 small light-blue dots are wielen, ponds scoured out where a dike once broke (RCE). Only eight have a recorded year, so the others are shown from the end of 1953, once the last great flood is over. The coastline, the big lakes and the flood of 1953 come from the map 'How the Netherlands Rose from the Sea' and are schematic (see that map for the method); small peat lakes are not drawn as water before they are drained. Sources: Rijksdienst voor het Cultureel Erfgoed, Landschapsatlas (CC0): Molens, Verdwenen molens (molendatabase.org / De Hollandsche Molen), Gemalen (Nederlandse Gemalenstichting), Droogmakerijen and Molens en gemalen (after Geuze & Feddes, Polders!, 2005), Wielen; J. Bazelmans, Het molensterven in Nederland (Tijdschrift voor Historische Geografie, 2023); Flevolands Geheugen on drainage by windmills and engines; Geschiedenis van de techniek in Nederland 1800–1890, vol. II; Rijkswaterstaat (floods of 1926 and 1995, IJmuiden, Afsluitdijk 2026); KNMI (Rhine and Meuse discharges 1926, 1993, 1995); Wageningen University & Research (flood of July 2021); Utrecht University (Wilnis 2003, Veenendaal 1855); Wikipedia (Kinderdijk windmills, Ir. D.F. Woudagemaal); coastline after Vos et al., paleogeographic maps of the Netherlands (Deltares/RCE).
Timeline
| Date | What the map shows |
|---|---|
| 1400 | 1400 · Peat land sinks behind its dikes |
| 19 Nov 1421 | 1421 · St Elizabeth's Flood |
| 1450 | 1450 · The first polder windmills in Holland |
| 1500 | 1500 · Windmills spread over Holland's peat |
| 26 Sep 1509 | 1509 · The Dollard at its largest |
| 5 Nov 1530 | 1530 · St Felix's Flood drowns east Zuid-Beveland |
| 1 Nov 1570 | 1570 · All Saints' Flood |
| 1 Jul 1584 | 1584 · Saeftinghe lost in the war |
| 1 Jul 1597 | 1597 · The Zijpe diked |
| 1 Jul 1612 | 1612 · Windmills pump the Beemster dry |
| 1 Jul 1622 | 1622 · The Purmer is drained |
| 1 Jul 1626 | 1626 · The Wijde Wormer is drained |
| 1 Jul 1635 | 1635 · Schermer and Heerhugowaard |
| 1 Jul 1643 | 1643 · The Haarlemmermeer becomes one lake |
| 1 Jul 1700 | 1700 · 1,196 polder windmills on record |
| 25 Dec 1717 | 1717 · The Christmas Flood |
| 1740 | 1740 · Kinderdijk's rows of mills are built |
| 1 Jul 1750 | 1750 · Peat diggers turn land into lakes |
| 1787 | 1787 · Steam is tried on the Blijdorp polder |
| 1809 | 1809 · Ice dams break the river dikes |
| 4 Feb 1825 | 1825 · Storm flood around the Zuiderzee |
| 1832 | 1832 · Cadastre: 4,242 polder mills on record |
| 1 Jul 1840 | 1840 · Zuidplas drained |
| 1 Jul 1852 | 1852 · Steam pumps the Haarlemmermeer dry |
| 1861 | 1861 · The Waal dike breaks at Leeuwen |
| 1 Nov 1876 | 1876 · North Sea Canal, new polders |
| 1890 | 1890 · 295 steam pumping stations built so far |
| 1900 | 1900 · Still 3,747 polder windmills standing |
| 14 Jan 1916 | 1916 · Zuiderzee flood brings the Zuiderzee Act |
| 7 Oct 1920 | 1920 · Wouda steam station opens at Lemmer |
| 31 Jul 1924 | 1924 · Wieringen joined to the mainland |
| 1926 | 1926 · Record Rhine flood; Meuse dikes break |
| 21 Aug 1930 | 1930 · The Wieringermeer falls dry |
| 28 May 1932 | 1932 · The Afsluitdijk closes the Zuiderzee |
| 9 Sep 1942 | 1942 · Noordoostpolder dry |
| 17 Apr 1945 | 1945 · Germans flood the Wieringermeer |
| 11 Dec 1945 | 1945 · Wieringermeer pumped dry again |
| 1 Feb 1953 | 1953 · The North Sea Flood |
| 6 Nov 1953 | 1953 · Last breach closed at Ouwerkerk |
| 29 Jun 1957 | 1957 · Eastern Flevoland dry |
| 1 Jul 1961 | 1961 · Delta Works: Veerse Gat closed |
| 1 Jul 1965 | 1965 · Grevelingendam |
| 29 May 1968 | 1968 · Southern Flevoland dry |
| 23 May 1969 | 1969 · The Lauwerszee closed |
| 1 Jul 1971 | 1971 · Haringvliet dams, Maasvlakte |
| 1 Jul 1975 | 1975 · IJmuiden pumping station; Houtribdijk |
| 4 Oct 1986 | 1986 · Eastern Scheldt barrier opened |
| 1 Feb 1995 | 1995 · 250,000 evacuated; the river dikes hold |
| 10 May 1997 | 1997 · Maeslant barrier completes the Delta Works |
| 22 May 2013 | 2013 · Maasvlakte 2 opens |
| 15 Jul 2021 | 2021 · Summer flood in Limburg |
| 31 Oct 2026 | 2026 · Pumps in the Afsluitdijk; 417 mills left |
Layers
Sea and lakes of the time · Lake pumped dry in the windmill era (to 1830) · Lake pumped dry in the steam era (1830–1918) · Lake pumped dry in the electric era (after 1918) · Land of the time · Polder windmills: 10+ per 100 km² · Polder windmills: 30+ per 100 km² · Polder windmills: 90+ per 100 km² · Mills on record only from 1832 (built earlier)
Events
- 1408, First recorded polder windmill, Alkmaar (1408): The oldest firm record of wind-driven drainage in Holland: in 1408 two councillors from Delfland travelled to Alkmaar to see the mill of Floris van Alkemade and Jan Grietensz., which 'had thrown out water'. Earlier dates that are sometimes given (1282, about 1326) are disputed. A scoop-wheel mill li…
- 19 Nov 1421, St Elizabeth's Flood: On 18–19 November 1421 dike breaches drowned the Grote Waard between Dordrecht and Geertruidenberg (2,000 to 10,000 dead). Much of it never came back: it became the Biesbosch, and Dordrecht became an island.
- 26 Sep 1509, The Dollard at its largest: The Cosmas and Damian flood of 1509 drove the sea far inland. Around 1520 the Dollard covered some 340–350 km²; from the 16th century both shores were diked back step by step.
- 5 Nov 1530, St Felix's Flood ('Evil Saturday'): On 5 November 1530 the eastern part of Zuid-Beveland drowned; of the Oost-Watering only the town of Reimerswaal was spared. This is the Verdronken Land van Reimerswaal. The town itself, left on an island, was given up in 1632.
- 1 Jul 1584, Saeftinghe drowned: During the Eighty Years' War, Dutch troops breached the last dike to stop the Spanish around Antwerp; Saeftinghe sank under the Scheldt. It is now the salt marsh of the Verdronken Land van Saeftinghe.
- 1 Jul 1612, Beemster drained: Amsterdam merchants financed the drainage; windmills pumped the lake dry between 1609 and 1612 and the land was divided among the investors. Its grid of roads and plots has been a UNESCO World Heritage Site since 1999.
- 1 Jul 1635, Schermer drained: The Schermer (1635) and Heerhugowaard (1631) completed the great windmill drainages of Noord-Holland's "Land of Leeghwater".
- 1 Jul 1643, The water wolf: Storms merged four lakes south of Haarlem into one Haarlemmermeer: 26 km² in 1531, about 150 km² by 1647, and still eating its shores.
- 25 Dec 1717, Christmas Flood of 1717: On Christmas night 1717 a storm surge broke the sea dikes around the North Sea, killing about 14,000 people, 2,500 of them in the Netherlands. Villages behind the dikes of Groningen were devastated.
- 1740, Kinderdijk: rows of polder mills (1738–1740): The eight brick mills of the Nederwaard were built in 1738 and the eight wooden mills of the Overwaard in 1740, to lift the water of the Alblasserwaard into a reservoir from which it could run out into the river. With three neighbours of 1630, 1740 and 1761 they form the group of 19 mills that has b…
- 1 Jul 1750, Lakes dug for fuel: Peat dug from below the water table for fuel left lakes behind all over Holland; many were drained again in the 18th and 19th centuries.
- 1787, Steam is tried: Rotterdam, Blijdorp, Mijdrecht (1776–1794): In 1776 Steven Hoogendijk tested a steam engine to pump water out of Rotterdam. In 1787 a steam pumping station of 43 m³ a minute went into operation on the Blijdorp polder, shown here. The first that worked for a polder for years stood at Mijdrecht (1794, shut down after 1812 because of the cost).…
- 1809, River flood of January 1809: In January 1809 ice dams broke the river dikes. Large parts of the land between Rhine and Meuse, the land between Meuse and Waal and land along the IJssel were flooded; in the village of Erichem alone 15 people died and 33 houses were destroyed. Relief collections raised 833,000 guilders within two…
- 4 Feb 1825, Flood of February 1825: On 3–5 February 1825 a storm surge broke the Zuiderzee dikes. Almost the whole Kop van Overijssel, the south of Friesland and Waterland north of Amsterdam were flooded, and so were parts of Groningen. 379 people died in the Netherlands, 305 of them in Overijssel.
- 1 Jul 1852, Haarlemmermeer pumped dry: Three steam pumping stations (Leeghwater, Cruquius and Lynden) pumped 800 million tonnes of water out between 1848 and 1 July 1852, adding 170 km² of land.
- 1861, Waal dike breaks at Leeuwen (February 1861): In February 1861 the Waal dike broke at Leeuwen and the Land van Maas en Waal was flooded; 37 people died. As long as the rivers stood high the river polders could only drain through their sluices: steam pumping stations followed along the rivers in the decades after.
- 14 Jan 1916, Zuiderzee flood of 1916: On 13–14 January 1916 a storm flood broke dikes around the Zuiderzee. Two years later parliament passed the Zuiderzee Act, Cornelis Lely's plan to close and drain it.
- 7 Oct 1920, Ir. D.F. Wouda steam pumping station, Lemmer (1920): Queen Wilhelmina opened the station on 7 October 1920 (the pumping-station register dates its founding to 1915). It can pump 4,000 m³ a minute out of the Frisian lakes and is the largest steam pumping station in the world still in operation, fired up in high water about once a year. UNESCO World Her…
- 1 May 1923, De Hollandsche Molen founded (1923): In May 1923 the society De Hollandsche Molen was founded in Amsterdam to save the windmills that steam, diesel and electricity were making redundant. Today's 417 complete polder windmills are about a tenth of the number on record around 1880.
- 1926, River flood of 1926: Meuse dikes break: On New Year's Eve 1925 the Meuse dike gave way near Nederasselt, tearing a gap 100 m wide; along the Meuse 39 dikes broke and the Land van Maas en Waal flooded. About 3,000 houses were damaged. In January 1926 the Rhine at Lobith carried 12,600 m³ a second, the highest discharge ever measured there.…
- 21 Aug 1930, Wieringermeer dry: The first Zuiderzee polder (200 km²) fell dry on 21 August 1930, after the dike to Wieringen was closed in 1929.
- 28 May 1932, Afsluitdijk closed: On 28 May 1932 the last gap in the 32 km Afsluitdijk was closed: the Zuiderzee became the freshwater IJsselmeer.
- 9 Sep 1942, Noordoostpolder dry: The 480 km² Noordoostpolder fell dry on 9 September 1942, in the middle of the German occupation. The islands of Urk and Schokland became part of the mainland.
- 17 Apr 1945, Wieringermeer flooded: On 17 April 1945, weeks before the liberation, German troops blew up the dike in two places; the polder was under water within two days.
- 1 Feb 1953, North Sea Flood of 1953: In the night of 31 January to 1 February 1953 a storm surge broke the dikes of Zeeland, South Holland and West Brabant. 1,836 people died in the Netherlands.
- 29 Jun 1957, Eastern Flevoland dry: The 540 km² polder fell dry on 29 June 1957; Lelystad and Dronten were built on it.
- 29 May 1968, Southern Flevoland dry: The 430 km² polder fell dry on 29 May 1968; Almere was founded on it in 1976.
- 23 May 1969, Lauwerszee closed: A dam closed the Lauwerszee on 23 May 1969: the tidal bay became the Lauwersmeer.
- 1 Jul 1975, IJmuiden pumping station (1975): The state pumping station at the sea locks of IJmuiden lifts the water of the North Sea Canal and the Amsterdam–Rhine Canal into the sea when it cannot run out by gravity. It opened in 1975 with four pumps; two more were added in 2004, for 260 m³ a second in all. It was long the largest pumping stat…
- 4 Oct 1986, Eastern Scheldt barrier: Instead of a closed dam, the Oosterschelde got a storm-surge barrier with 62 gates that stay open, keeping the tides and the estuary alive. Opened 4 October 1986.
- 1 Feb 1995, High water of 1995: 250,000 evacuated: On 31 January and 1 February 1995 more than 250,000 people and a million animals were evacuated from the river polders. The Rhine reached 16.68 m above NAP at Lobith (12,060 m³ a second, second only to 1926). The Waal dike at Ochten began to shift but held, and no dike broke. With the Meuse flood of…
- 10 May 1997, Maeslant barrier: Two floating gates, each 210 m long, swing shut across the Rotterdam Waterway in a storm. Opened 10 May 1997, it completed the Delta Works.
- 22 May 2013, Maasvlakte 2: About 2,000 ha of new port land, opened on 22 May 2013.
- 15 Jul 2021, Summer flood in Limburg (July 2021): Extreme rain over the Ardennes, the Eifel and South Limburg in mid-July 2021 made the Geul burst its banks; in Valkenburg alone 2,300 houses were damaged. At Maastricht the Meuse rose in two days from 50 to about 3,300 m³ a second, more than the winter record of 1993 (3,039 m³/s at Borgharen).
- 25 Oct 2022, Hedwigepolder given back to the Scheldt: On 25 October 2022 the tide ran into the Hertogin Hedwigepolder again. Diked in 1907, it was the last land won from the sea in eastern Zeeuws-Vlaanderen; its 299 ha are now tidal nature in the Western Scheldt, as agreed with Flanders in the Scheldt treaties of 2005. Land that goes back to the water,…
- 1 Oct 2026, Pumps in the Afsluitdijk (2026): On 1 October 2026 the new pumping station and discharge sluices in the Afsluitdijk at Den Oever were put into use: six pumps with a combined capacity of 275 m³ a second. As the sea rises, the hours in which the IJsselmeer can drain by gravity at low tide grow fewer. The rule is: sluice when you can,…