Definition Collecting and storing rainwater for subsequent use ﾖ for example, using water butts or larger storage tanks. - Based on Stella definitions, adapted by NWRM project experts and validated by the European Commission Links Relation type Narrower Concept Natural Water Retention Measure References CIRIA, 2007. The SUDS Manual. C697.| Themes urban area Type of action Urban planning Biophysical benefits Sustainable drainage & Runoff control