Unprecedented 1D helical chains of hydrogen bonded water molecules, showing both handedness and anchored onto a helical supramolecular host formed from the self assembly of a dicopper(II) complex (1) containing pentadentate Schiff base (L) and p-hydroxycinnamate in 1·2H₂O, propagate along the crystallographic 2₁-screw axis and the compound shows two endotherms due to loss of water molecules at 61.5 and 88.5 °C in the differential scanning calorimetry giving an overall change of enthalpy value of ∼36 kJ mol⁻¹ per water molecule.