Periodic flooding is a natural occurrence in riparian systems and the species which make riparian corridors their home have evolved mechanisms for tolerating floods. Flooding events replenish floodplains with sediment and organic matter. High flow events also wash woody debris into streams, providing critical cover and spawning areas for many fish species. Additionally, floods transport necessary sediment and organic materials to river deltas. Though floods can change the look and feel of a riparian area, these systems have evolved with and depend upon these structure-altering events.
Naturally occurring events such as wildfire and heavy winds can also alter stream systems. Though the impacts of these events can sometimes appear devastating, riparian areas and their inhabitants can typically recover from them without human intervention.
Flooding events can uproot trees and redirect river flow.