The post Little Ice Age warming generates in polar environments paraglacial processes (Church and Ryder, 1972) marked by the prevalence of run-off over the zonal processes (glacial and periglacial). Indeed, in Spitsbergen, the retreat recorded by the Brøgger peninsula's glaciers induces the release of large amounts of proglacial liquid water reaching the Kongsfjord. This results into the development on the proglacial margins of a complexe and very mobile hydrographic network. However, we could demonstrate that this mobility decreases with the time. The hydrographic network adopts an increasingly stable organization marked by the reduction of the number of channels and a growing hierarchisation in spite of its extreme youth.