Rappbode Reservoir (IMAGE) Helmholtz Centre for Environmental Research - UFZ Caption The Rappbode reservoir in the Harz region -- it also is affected by the increasing brown coloration of the water. It is one of 36 reservoirs in Germany which have been studied by UFZ scientists in order to identify the causes of increasing brown coloration. Credit UFZ / André Künzelmann Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.