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Newsletter and Technical Publications

Lakes and Reservoirs vol. 3

Water Quality: The Impact of Eutrophication


Social, Cultural, Institutional and Economic Aspects of Eutrophication

The Economic Value of Water Resources

Photo 29: Clean water flowing from a drinking fountain in Venice, Italy.

Water resources are environmental assets and therefore have a price. There are market-based methods to estimate costs and benefits, and these make it possible to use cost- benefit analysis as a useful tool to assess the economic effects of abatement of eutrophication or other pollution problems. Benefits range from higher quality drinking water and reduced health risks (Photo 29) to improved recreational uses (Photo 30). The effects on human health from the lack of sanitation and the chronic effects of toxic algal blooms are two of the many indirect effects resulting from eutrophication. Numerous cost-benefit analyses of pollution abatement have clearly demonstrated that the total costs to society of ‘no pollution reduction’ is much higher than at least a ‘reasonable pollution reduction’.

Photo 30: Some recreational use of lakes.

Consequently, it is necessary to examine the prevention of pollution and restoration of water quality in lakes and reservoirs from an economic standpoint. The result of such examinations should be applied to assess effluent charges and green taxes. International experience shows that these economic instruments are reasonably effective in improving water quality and solving related water pollution problems. Thus, effective planning and management of lakes and reservoirs depends not only on a sound understanding of these water-bodies as ecological systems but also of their value to people as recreational areas and water resources.

In the past, several management strategies were developed and applied to solve problems of decreasing surface and groundwater quality. These were often a response to acute critical situations resulting in increased costs of water. The demand for good quality fresh water was only solved partially and locally; this was because too few resources were allocated too late to solve the problems. Early prevention is by far the cheapest method to avoid later pollution.

The need to integrate social and cultural issues in a new management strategy

A new management approach is needed which integrates scientific and technological knowledge with social, cultural and political issues for sustainable development of water resources for human needs. The implementation of the watershed concept by establishing national and international Watershed Committees is fundamental in developing effective management strategies for lakes and reservoirs. Based on the ecosystem concept and an integrated planning approach, the training of decision-makers and managers is an indispensable component in this strategy.

It is often not safe to consume water in developing countries. Changes to perceptions of the value of water to meet changes in the management of water resources, the need of the aquatic environment and the entire ecosystems in these countries are needed. It will be difficult to make such changes given current inertia towards the value of water, but public awareness and environmental education are steps in the right direction.

Many factors affect water quality in developing countries, particularly increasing eutrophication: industrialization, urban development, new land-use practices and change in the use of water. Given these changes, it is important to integrate hydrological, social, economic and cultural aspects with scientifically-based knowledge of lakes and reservoirs. The social aspects of eutrophication are often overwhelming in developing countries. The loss of jobs resulting from heavy fish kills due to oxygen depletion is just one example of a massive social impact resulting from eutrophication.

Photo 31: Deforestation, erosion, and open-mining activities which cause freshwater quality degradation.

A new management strategy should recommend several alternatives to present practices. For instance, one should recommend that soil erosion can be stopped or at least reduced by stopping deforestation and burning techniques (Photo 31) in farming. Implementing prevention, control and management of eutrophication within an integrated strategy can provide new job opportunities and tools for economic development, with corresponding social benefits.

      Table of Contents

  • Brochure
  • IETC Brochure


  • International Year of Forests
  • International Year of Forests


  • World Environment Day
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  • UNEP Campaign
  • UNite to Combat Climate Change