 Fire can significantly alter hydrologic processes leading to increased risks of extreme floods and erosions. Catchment scale studies on the hydrologic impacts of fire in Europe are rare and nested approaches are seldom used. To address this gap, we conducted a catchment scale experimental fire in Portugal to better understand the drivers of fire impact on hydrology. Our results show that fire increased stream flow volumes by 1.6 times more than expected, resulting in faster drying of soils after rain events and changing rainfall runoff relationships. Additionally, fire increased the response of topsoil moisture to rainfall from 2.7 to 2.1 hours, suggesting that vegetation removal played an important role in increasing stream flow after fire. These findings demonstrate that fire impact on hydrology is strongly dependent on scale and underscore the need for further research on the topic. This article was authored by C.R.Stuff, R.W.Vervort, J.I.Weema, and others. We are article.tv, links in the description below.