Through this study, we established the taxonomic status of seven strains belonging to the Pectobacterium genus (A477-S1-J17 T , A398-S21-F17, A535-S3-A17, A411-S4-F17, A113-S21-F16, FL63-S17 and FL60-S17) collected from four different river streams and an artificial lake in southeast France between 2016 and 2017. Ecological surveys in rivers and lakes pointed out different repartition of strains belonging to this clade compared the closest species, P. aquaticum. The main phenotypic difference observed between these strains and the P. aquaticum type strain was a strongly impaired growth with rhamnose as sole carbon source. This correlates with three different forms of pseudogenisation of the L-rhamnose/proton symporter gene rhaT in the genomes of strains belonging to this clade. Phylogenetic analysis using gapA gene sequences and MLSA analysis of the core genome showed that these strains formed a distinct clade within the genus Pectobacterium closely related to Pectobacterium aquaticum. In silico DNA-DNA hybridization and average nucleotide identification values showed a clear discontinuity between the new clade and P. aquaticum. However, the calculated values are potentially consistent with either splitting or merging of this new clade with P. aquaticum. In support of the split, ANI coverages were higher within this new clade than between this new clade and P. aquaticum. The split is also consistent with the range of observed ANI or dDDH values that currently separate several accepted species within the Pectobacterium genus. On the basis of these data, the strains A477-S1-J17 T , A398-S21-F17, A535-S3-A17, A411-S4-F17, A113-S21-F16, FL63-S17 and FL60-S17 represent a novel species of the genus Pectobacterium, for which the name Pectobacterium quasiaquaticum sp. nov. is proposed. The type strain is A477-S1-J17 T (=CFBP 8805 T =LMG 32181 T).