Polder

Polder is a low-lying reclaimed land enclosed by dike, with manually operated water devices to control the inner water level. Instead of raising the property land through sand or added soil, polder works through exclusion and evacuation of the outside water. Polder normally associated with the Dutch way of dealing with flood. They have been using the system since 11th century to create available land for housing and agriculture. In the very beginning, polder was built through self-organization of the farmers. Later, the scale of organization went up as several communities form a larger organization, called “water boards”. This board acts independently from the government to achieve its objectives. Until now, there are 25 water boards in the Netherlands.

Sources: Ministry of Public Works et.all. Urban Polder Guideline

Polder system illustration. Sources: Ministry of Public Works et.all. Urban Polder Guideline

This system works for an area with rising sea and river levels, sinking land levels, increasingly multi-functional use of land (urbanisation, recreation or tourism, nature and culture conservation), interference of agricultural policies and others 1. There are several steps need to be done in empoldering:

1. Select the low lying land to reclaim with intended purposes.

2. Enclose it with dikes to protect from outside water.

3. Pump the water out by building pumping station.

4. Plant salt-loving or water-absorbing vegetations to absorb the excess water in the soil

5. Construct drainage system, pumping station and canals to regulate the water level.

6. After the land is ready in several years, polder can be designated for specific land uses.

 

hoe_comp

How the Dutch create the polder illustration. Source: http://static.nai.nl/polders/e/hoe_e.html

 

1. Schoubroeck, Frank van. The remarkable history of polder systems in The Netherlands. 2010. Available from: http://www.fao.org/fileadmin/templates/giahs/PDF/Dutch-Polder-System_2010.pdf

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