The use of large wood in stream restoration: Experiences from 50 projects in Germany and Austria

This study reviews the use of large wood in stream restoration across 50 projects in Germany and Austria, highlighting its potential to improve hydromorphological and ecological conditions. Results show that many projects use wood volumes and structures below natural levels, often placing wood parallel to flow, limiting effectiveness. Only 58% of projects monitored restoration success. Key findings include the importance of watershed-scale evaluation, the benefits of mimicking natural wood, and variable effects depending on stream size and hydrology. Fixed wood (‘hard engineering’) dominates, but non-fixed (‘soft engineering’) methods are more cost-effective and create more natural features. The authors recommend increasing wood quantity and size, improving monitoring, and prioritising passive restoration—restoring natural wood recruitment processes—over active placement as a sustainable long-term strategy.