Finding a causal mechanism to account for observed phases of valley alluviation in the Mediterranean region and southern Europe during the Holocene has been a subject of debate for more than 20 years. Three possible causes have been suggested: regional climatic change, anthropogenic induced erosion, and the crossing of intrinsic thresholds within fluvial systems so that deposition, rather than erosion, is favored. This article reports investigations carried out in the Algarve region, southern Portugal. Mapping and sedimentological investigations of Holocene sediments are reported, together with the association with artifacts, a Roman and Moorish mill, and bands of charcoal. It is argued that in this area anthropogenic forcing of phases of Holocene alluviation is the preferred mechanism.