Editing Zuiderzee Works (section)

===Land reclamation===
After damming off the sea, the next step involved creating new land, known as polders. This was achieved by damming off portions of the IJsselmeer, and then pumping all the water out. The first polder, [[Wieringermeer]], was dammed in 1929 and fully drained in 1930. The third, the [[Noordoostpolder]], was not fully drained until 1942. It was an area much used by the Dutch [[Resistance during World War II|Underground resistance]] during [[World War II]], as the fresh polder offered numerous hiding places.

After the war, work was started on draining the Flevolands, a massive project totalling almost 1000&nbsp;km<sup>2</sup>. This area is now home to [[Lelystad]] and [[Almere]]; the latter is the fastest growing city in the Netherlands (in part because of its proximity to [[Amsterdam]]). Another large polder was originally planned in the [[Markermeer]]. This project was extensively debated until plans were abandoned in the early 2000s, as environmental issues were viewed differently than in the 1920s. A new province, [[Flevoland]], was created out of the Noordoostpolder and the Flevolands in 1986, thereby completing the Works.

This new land led to an identity change for towns including [[Lemmer]], [[Vollenhove]], [[Blokzijl]] due to losing their direct access to the sea and [[Kuinre]] was completely cut off from open water. The former islands of [[Urk]] and [[Schokland]], and [[Wieringen]] got connected to the mainland.

The other major project started in 1927 was the construction of the {{cvt|200|km2}} polder in the northwest, the first and the smallest of the five projected polders. It replaced the [[Wieringermeer]], the body of water south of Wieringen, and also the name of the new polder. It was the only polder reclaimed from the Zuiderzee itself (the others were reclaimed after the Afsluitdijk was finished), but it wasn't entirely the first. A small test polder of some 0.4&nbsp;km<sup>2</sup> was constructed in 1926{{mdash}}1927 near Andijk in North Holland to research the effects drainage would have on the soil of the Zuiderzee and how best to configure the new polders.

Building the encircling dike for the Wieringermeer was harder than it was for the later polders, because the Wieringermeer dikes were built before the completion of the Afsluitdijk. That meant the tidal currents of the Zuiderzee were still present. As a consequence, they were somewhat higher. Construction started on the {{cvt|18|km}} dike from Den Oever on Wieringen and the new construction-island of Oude Zeug and progressed satisfactorily. The Wieringermeer was closed off from the Zuiderzee in July 1929. The next step was draining all the water from the future polder.

Drainage of a polder is performed by a pumping station or mill (''[[gemaal]]'' in Dutch). Two were built for the Wieringermeer, the ''Leemans'', a [[diesel engine|diesel]] powered station, near Den Oever and the ''Lely'', an electrically powered one, near [[Medemblik]]. Different power systems were used in the stations as a safety  mechanism. If one station lost power, the other one would still be able to keep the polder dry. The pumping mechanism itself was based on a variation of [[Archimedes' screw]], as designed by [[A. Baldwin Wood]]. The stations, completed in February 1930, managed to drain the polder after six months of continuous pumping. "Drained" in this context does not mean the land was wholly dry; extensive pools of shallow water still littered the muddy landscape. To make the soil usable it had to be further drained by a network of drainage canals. Small ditches were dug leading to larger watercourses, which in turn transported their water to the main drainage canals. These canals, dredged when the polder was still filled with water, conducted surplus water to the pumping stations. The resulting dehydration caused the former seabed to sink by over a metre in some places. Once the ground had settled, the smaller ditches were replaced with underground drainage tubes, which would be used for the normal drainage of the polder.

{| class="wikitable floatright"
|+Land Usage of the Polders<br>(percentage of total surface area){{citation needed|date=August 2015}}
|-
|bgcolor="lightgrey"|Polder
|bgcolor="lightgrey"|Size
|bgcolor="lightgrey"|Agriculture
|bgcolor="lightgrey"|Housing
|bgcolor="lightgrey"|Nature
|bgcolor="lightgrey"|Infrastructure
|-
|Wieringermeer
|200&nbsp;km<sup>2</sup>
|align="center"|87%
|align="center"| 1%
|align="center"| 3%
|align="center"|9%
|-
|Noordoostpolder
|480&nbsp;km<sup>2</sup>
|align="center"|87%
|align="center"| 1%
|align="center"| 5%
|align="center"|7%
|-
|Eastern Flevoland
|540&nbsp;km<sup>2</sup>
|align="center"|75%
|align="center"| 8%
|align="center"|11%
|align="center"|6%
|-
|Southern Flevoland
|430&nbsp;km<sup>2</sup>
|align="center"|50%
|align="center"|25%
|align="center"|18%
|align="center"|7%
|}

With the hydrological infrastructure in place, the virgin land was developed to prepare for its later cultivation. The first plant to establish itself, though more so in the later polders than in the Wieringermeer, was [[Phragmites|reed]], sown from the air by plane onto the muddy flats while the polder was still being drained. This sturdy plant helped evaporate the water and bring air into the soil, thereby solidifying its structure and further preventing the emergence of unwanted weeds.

After the first infrastructure was put in place, the reed was burnt and replaced by [[rapeseed]], turning the newborn polder into a yellow sea of flowers in spring. These crops were succeeded by various grains. In the Wieringermeer the first was [[rye]], but the later polders plant wheat, then [[barley]], and finally oats. This process took years, but once finished allowed planting other crops. At the same time, other infrastructures such as roads and housing were built.

The Wieringermeer and later polders were divided into plots of about {{convert|50|acre}}. The best land is used for vegetables; the next best for rye and other grain; and the worst land is forested. Each plot has a paved road in the front and a canal in the back to make it accessible by land and water. A [[terp]] in the center of the polder is built higher than the highest recorded flood level of the North Sea to protect people if the dike fails; the Wieringermeer terp is large enough to hold the population of Amsterdam.{{r|ley196110}}

During the [[German occupation of the Netherlands]] in World War II the invading forces at first did not interfere; their engineers inspected the project as a model for reclaiming the [[Frische Haff]]. In 1945 retreating Germans ordered the [[inundation of the Wieringermeer]], but it was drained again afterwards and the damage repaired.{{r|ley196110}}