2-[(2-Hydroxyethyl)azaniumyl]ethanaminium oxalate monohydrate

In the title hydrated molecular salt, C4H14N2O2+·C2O42 ·H2O, the oxalate dianion is almost planar (r.m.s. deviation = 0.020 ). In the crystal, the components are linked by N—H...O(water), N—H...O(oxalate) O—H(ammonium)...O(oxalate), O—H(water)...O(oxalate) and O—H(water)...O(ammonium) hydrogen bonds, thereby forming a complex three-dimensional packing motif.