The researchers conducted a choice experiment in four countries – Germany, Sweden, Norway and France. Around 1000 citizens were surveyed in each of the countries, as a representative cross-section of the respective "online population". Respondents were asked to select preferred combinations of ecologically relevant attributes for the rivers in their residential environment, with the provison that they would have to make an obligatory financial contribution to a river development fund to achieve the selected river status. From the responses, the researchers were able both to identify the preferences of the population for river characteristics and to estimate the willingness-to-pay for the improvement of rivers.
Positive willingness to pay for ecological upgrading of rivers, irrespective of country
Respondents from all countries favoured rivers with high bathing water quality and biodiversity, and with characteristic river fish species such as sturgeon, brown trout and salmon. From this it can be deduced that ecologically oriented programs for the renaturation of watercourses can in principle create positive values for the population. "These results can be seen as a signal to policy makers to step up their efforts to improve water quality and the ecological status of rivers," says first author of the study, Dr Carsten Riepe of the IGB.
In Germany: 79 euros plus for better bathing water quality, 98 euros minus for the expansion of hydropower.
To improve the water quality of rivers, Germans would be prepared to spend 79 euros per person and year. The German population also valued good river continuity, for example to ensure fish migration, as a further river characteristic – somewhat more than the occurrence of certain fish species or the promotion of a high native biodiversity. Expressed in figures: An expansion of hydropower beyond today's levels would lead to a loss of benefit of almost 100 euros per person and year in Germany.
If several river characteristics were to be improved at the same time, for example through higher water quality, free flow stretches and the promotion of native biodiversity, the population in Germany would benefit from a willingness-to-pay of EUR 675 per capita per year. Assuming one person per household, ecological river restoration in the residential environment of each of the 41 million private households would result in a projected benefit of around 27 billion euros per year. If the figures are applied to all persons over the age of 18, there would even be a benefit of 47 billion euros per year. Although such survey results are always fraught with methodological uncertainties, the figures show impressively that a high ecological river quality also enjoys very high esteem among Germans and that river improvement can also be economically worthwhile.
"The high social value that near-natural rivers have from the point of view of society can economically justify the nationwide implementation of the objectives of the EU Water Framework Directive. After all, achieving ecological objectives costs a lot of money. With our study, decision-makers now have figures at their disposal that can be incorporated into cost-benefit calculations when considering investments in river development," sums up Robert Arlinghaus, head of the study and fisheries scientist at the IGB and Professor of Integrative Fisheries Management at Humboldt-Universität zu Berlin.
The study was funded by the German Research Foundation as part of the SalmoInvade project.