• What is water?
• Water use
• Water management
• Coastal protection
• Durable water management
• Example projects
• New water management in the Netherlands
• Organisations
• Normal Amsterdam Water Level

• Deltawerken Online wordt mede gemaakt door:

  
  
  
  
  
  

Durable water management

The term ‘durable water management’ arises from the last decade. The important question is, what it means and what its results are. Durable water management is the control, use and return of water, under a number of conditions. Firstly, the natural supply should not be exceeded. Secondly, the use of water should be geared to the quality of the water - so when the water is returned to nature, it should not be harmful. Thirdly, the size of water use should be small, and the duration of use as long as possible. The natural circumstances under which water is won over and returned to the environment should be maintained.

Winning and using

One of the goals of durable water management is to return used water to the environment in at least the same quality as it was extracted. In West-European countries, 16 percent of available freshwater is withdrawn from the environment. Five percent of this water is used and does therefore not return to nature. Of course, the water does not disappear completely; some of the water will evaporate and return to nature in the form of rain for example. Since water use is higher in arid areas (for instance in Mediterranean countries), these countries will dry out even faster. Another way in which the environment may be harmed, is by returning water to another place from which it was withdrawn. If more water is withdrawn from a river than is returned, the river could dry up.

The rise of durable water management

Durable water management is the awareness that natural resources are not inexhaustible and that mankind should take special care of the world. Especially since the publication of the report Border on Growth, by the Club of Rome in 1972, environment has become an important issue. The most important problems with regards to water were identified as water shortage, desert forming and floods. To resolve these problems, large international and unfeasible projects were often planned. During the last fifteen years, the focus has been on small-scale projects which are easier to finance and implement. The results of the projects can be measured more effectively too. Every year, dozens of small-scale projects are carried out in the Netherlands in order to make durable water management and water use possible.

Instruments of durable water management

The government has many different instruments to influence the Dutch water management. An economic instrument is the control of the demand for water. The Dutch government tries to persuade people and companies to use water in a rational and economical way. Water-use indicators can be installed and information can be supplied via newspapers, radio and television. Another way in which heavy use of water can be discouraged is to levy taxes. Moreover, the distributive system and the technique of water withdrawal could be improved, so that less water is wasted. It may only look like a drop in the ocean, but the leakage of water in most European countries is very high. The leakage varies from 3.7 m3 for every kilometre of mains pipes in Germany (112 litres of water per household per day) to even 8.4 m3 per kilometre in England (243 litres of water per household per day). The construction of new houses often offers the opportunity to use new techniques with regards to water management. When water reservoirs are built, rainwater can be reused for other purposes (like watering the garden or the houseplants).

The National Water Agreement

On July 2nd, 2003, the Dutch national government, the county councils/boards, the local authorities and the Rijkswaterstaat (which may be compared to the Department of Public Works) signed the National Water Agreement. A new form of water management is needed, since meteorological changes - with further extreme periods of drought and precipitation are predicted. A new policy has to be developed also because of fluctuations in river drainage and the rising sea level. This policy follows the objectives of durable water management. In contrast to the past, it is no longer acceptable to drain redundant water out to sea, but to retain it at the location it naturally reaches (e.g. through of precipitation). If retaining is not an option, water can be stored in allocated areas. When water levels in rivers are too high, dikes are sometimes opened up on purpose, so that water can stream into polders which were chosen beforehand. During dry seasons, the water reservoir can be drawn upon.

A number of projects in 2003 were: het Woolde near Hengelo, rainwater seperation in Nijmegen, de Oost polder near Anna Paulowna, the Lappenvoort, Glimmermade and Oosterland polders, and the nature reserve Groote Brekken near Lemmer. These projects are the forefront of Dutch water management for the 21st century. In years to come, 250 more projects will take place in order to create additional space for water storage.