This work presents a few aspects regarding sediment yield, during some major floods, from the lower reach of the Siret Basin. After a brief presentation of the geomorphologycal and hydro-climatic conditions of the Siret Hydrographycal Space, we presents, on the base of the monitoring data from the hydrometric network, some floods that have occurred in 1991 and 2005 on the Trotus River, Putna River, Milcov River and Siret River (lower reach), from where it results the current morphogenetic potential of the hydrographycal network and the proportions of the anthropic impact