Quantifying the impacts of rewilding on hydrological extremes (floods and droughts)

Rewilding is a type of Nature-based Solution and has increased in popularity in recent years with rewilding projects rapidly increasing in number across Europe. Different definitions of rewilding have been proposed but it generally refers to large-scale, whole-ecosystem approaches to landscape restoration which can include the reintroduction of missing species. Rewilding has the potential to influence hydrological extremes (floods, droughts), which are expected to intensify with climate change, but the evidence base is limited. To address this gap, this project combines systematic literature review and meta-analysis of published data, an audit of existing publicly available hydrological data for rewilding projects and hydrological and hydrodynamic modelling of rewilding scenarios, calibrated using real-world data from two UK projects.

In this presentation we will share an analysis of published studies that indicates rewilding-driven landscape changes are likely to slow the flow of water through landscapes and attenuate flood peaks. In contrast, research on low flow outcomes is limited and outcomes are more complex. We will also illustrate that existing hydrological monitoring networks in the UK need to be expanded in order to effectively monitor the impact of rewilding projects on hydrological extremes. Preliminary results from modelling rewilding outcomes at UK rewilding projects will also be discussed.