This dataset provides river discharge measurements collected at selected locations in the Atchafalaya and Terrebonne Basins within the Mississippi River Delta floodplain in coastal Louisiana, USA. The measurements were made during the Delta-X Spring campaign from 2021-03-26 to 2021-04-11. Channel surveys were conducted with a Teledyne RiverPro acoustic doppler current profiler (ADCP) on selected wide channels (>100 m wide) and a few selected narrow channels (approximately 10 m wide).