Extended hydrometric (absolute water level and river flow) records produced via data rescue are presented for eight Irish catchments subject to arterial drainage. Records cover the period 01/10/1939 to 30/09/2021. For three catchments, additional metadata are provided to summarise the quality of rescued autographic chart records. The accompanying paper presents the procedures employed to collect and process historical data, extend flow records, and compile key metadata and information about each gauging station. The newly extended records represent the longest continuous river flow series available in Ireland, extending to the commencement of formal hydrometric monitoring in the country in 1939/1940. These data offer new insights into environmental history in Ireland and provide new empirical data for use in hydrological modelling.