Sedimentation in small reservoirs on the San Rafael Swell, Utah

Abstract

Movement of sediment from upland areas and eventually into main drainages and rivers is by no means through continuous transportation of material from the source to the delta. Instead it consists of a series of intermittent erosional and depositional phases that present a pulsating movement. Hence, sediment carried off upland areas may be deposited in lower reaches or along main drainages if an existing combination of factors tend to effect deposition. During this period actual sediment movement out of the basin may be relatively small. Following any change in existing conditions, however, these unconsolidated alluvial fills may be subjected to rapid removal; thus, for a limited time, abnormally high sediment production rates occur until the deposits are either removed or another cycle of deposition is started.