What is special about Schalkwijk is that it is surrounded by water on three sides. The Spaarne meanders in the west, the Molenplas and the Meerwijkplas are in the south and the Ringvaart van de Haarlemmermeer is in the south and east. The Spaarne is a river that originally flowed between the Haarlemmermeer and the IJ. The Spaarne therefore ran and runs through Haarlem. Before there were railways and modern road traffic, the Spaarne was an important connection for Haarlem with the rest of the world. Since Haarlem grew big through trade and industry, such a waterway connection was essential. In 1852, the Haarlemmermeer was drained. The Spaarne then became a branch of the Ringvaart van de Haarlemmermeer. In 1876, the construction of the North Sea Canal was completed and large parts of the IJ were reclaimed. The Spaarne is now connected to the North Sea Canal by the Zijkanaal C. On the south and east side of Schalkwijk runs the Ringvaart of the Haarlemmermeer. The Ringvaart was dug to drain the Haarlemmermeer. The digging took place between 1839 and 1845 and was done by thousands of workers. The canal was dug as much as possible through the old land, along the shoreline of the Haarlemmermeer. But for example in Vijfhuizen, which is opposite Schalkwijk, an existing headland was dug through. On the south side of Schalkwijk lie the Molenplas and the Meerwijkplas. These lakes were created by sand extraction. Before large-scale housing construction started in Schalkwijk, the former peat polders were raised with a thick layer of sand. Some of the sand also comes from the dunes. From the west side of the Molenplas you have a beautiful view of the Verenigde Polders. These polders are largely used for agriculture. The municipality of Haarlem sees opportunities here for the development of an ecologically developed zone. Species such as Water Rail, Bittern and Grass Snake are being considered. Restaurant De Molenplas is located on the water and is a nice stop for a bite to eat or a drink. (Sources: Ecologisch Beleidsplan, deel 2, gemeente Haarlem; onh.nl/verhaal/het-spaarne; nl.wikipedia.org/wiki/Spaarne; nl.wikipedia.org/wiki/Ringvaart_van_de_Haarlemmermeerpolder; nl.wikipedia.org/wiki/Gemaal_De_Cruquius; gemeentebestuur.haarlem.nl/bestuurlijke-stukken/2015317036-19-BIJLAGEN-TOELICHTING-Bijlage-14-Cultuurhistorische-analyse-1.pdf)
In the past, the Lage Kadijk was closed off because of the meadow birds. This closure was not always to the satisfaction of local residents. For example, in 2016 an attempt was made to prevent the closure via a petition.
The black-tailed godwit is a meadow bird and is our national bird. In addition to the black-tailed godwit, the Bird Protection Association calls the following birds farmland birds: barn swallow, yellowhammer, yellow wagtail, meadow pipit, barn owl, lapwing, quail, corncrake, partridge, oystercatcher, shoveler, little owl, redshank, skylark, white wagtail and curlew.
However, the meadow birds in the Verenigde Polders are doing badly. This was already noted in 2012 by a bird working group. The working group then cited the following reasons: the low water levels due to agricultural business operations, intensive agricultural use (fertilization and early mowing) and an increase in predators. Predators here were fox, black crow, magpie, rats, seagulls and cats. In the Netherlands as a whole, meadow birds are doing badly. In 2024, the European Commission started a so-called infringement procedure, because the Netherlands is not doing enough to protect meadow birds and their habitats. The Netherlands is obliged to do so under the Birds Directive.