Researchers at Radboud University completed a study of greenhouse gases from ditches and ponds early this year. The newspaper Trouw reported that local ponds generate emissions equivalent to 200,000 cars. On the basis of available knowledge, Witteveen+Bos and Deltares developed a prototype tool to determine emissions from ponds and lakes. It will allow water managers to estimate greenhouse gas emissions and to think about how to cut those emissions. The tool and the initial measurement results were presented to water managers recently and they received an enthusiastic reception. A handbook is now being produced with information about the carbon processes and the link with eutrophication, how to use the tool, a step-by-step analysis, the role of sediment, and measures to reduce emissions. Witteveen+Bos and Deltares will soon be organising a conference on water quality and emissions that will be publicised through various channels as well as on their websites.

The link between water quality and emissions results in a win-win situation: it allows us to work not only on the WFD objectives but also on our climate ambitions. The IPCC values indicate that a 100-hectare lake emits 457 tonnes of CO2 equivalents a year. The IPCC does not yet take water quality into account and it shows the emissions of an 'average' lake. Indicative calculations with the model show that the difference in emissions between a eutrophic and an oligotrophic system can be a factor of 10. So this is a win-win situation that could have an enormous impact!