GRUNDFOS FOUNDATION RESEARCH The value of clean lakes Restoration of a lake to achieve better water quality will typically require measures that are associated with significant budget costs. As with any other investment it is relevant to consider whether the benefits of restoration outweigh the costs. Improving the water quality in a lake will rarely lead to significant increases in income for the individual landowner. Hence, lake restoration will typically be a poor investment if viewed from the owner's point of view. This is likely a major reason why there has so far been few lake restoration projects in Denmark, despite the increased amenity values that better water quality may provide. Thus, few lakes live up to the EU's Water Framework Directive’s target of good ecological status. In this regard, development of technology and methods for recovering and reusing phosphorus from the lake bottom sediment in connection with lake restoration presents an opportu- nity as the recovered phosphorus can L arge predator fish like this pike thrive in clear-water lakes. Caught in Birksø near Ry in Denmark. Photo: Jens Fich potentially be sold and thus create an income. In addition, the price of phosphorus is expected to rise in the coming years as the world's phosphorus reserves are used up. Whether this can turn lake restoration into a sound investment for the individual landowner is still unknown. Societal gains from lake restoration However, there may be several good reasons to invest public funds in lake res- toration. Rather than a narrow financial investment focus, at the societal level we should focus on creating the greatest possible well-being for the citizens in society. Clean lakes contribute to our well-being. Many people regularly use lakes and water areas to engage in a variety of outdoor activities. Some may to some extent be associated with user costs, such as angling and sailing. Others are considered free of charge, for instance walks along the water and bathing. Common for all these outdoor activities is that they have value for us. Improved water quality will increase these values. Better water quality will also increase biodiversity, which may have value for people both in terms of the opportunity to experience a more varied animal and plant life and in the mere knowledge that survival of animal and plant species is now better secured. Lake restoration can also lead to a reduction in greenhouse gas emissions, which clearly benefits society as it contributes to achieving political climate goals. In the project Sustainable Lake Stewardship, we aim to quantify and value all these benefits, enabling a direct comparison to the costs of the restora- tion of Lake Ormstrup. This will show the extent to which the restoration overall creates value for society. Subsequently, we expect to be able to transfer these experiences to other Danish lakes. Valuation of nature Several Danish and inter- national valuation studies document the high values that people attach to nature improvements, including im- provements in water quality, although none of these studies have focused specifically on Danish lakes. Read more in ‘Sæt pris på naturen’ published by Depart- ment of Food and Resource Economics, University of Copenhagen (in Danish). Find out more: e-pages.dk/ku/1379 48
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