Interaction energies of a water molecule with a model Cu(111) surface were investigated using the cluster model approach and high-level ab initio methods. Potential energy scans were calculated for a Cu-10 model cluster and a water molecule with a second-order Moller-Plesset (MP2) method using a RECP/6-31+G* basis set and counterpoise correction (CP) for the basis set superposition error (BSSE). Different adsorption sites and water orientations were considered. A full geometry optimization for a water molecule at the on-top adsorption site of the Cu-10 cluster gave 77 degrees for the optimal tilt angle between the water plane and the surface normal, and non-CP interaction energy of -41 kJ/mol. Interaction energies between a Cu-18 model cluster and H2O were also calculated at selected points. Without the CP correction, the orientation with hydrogens parallel to the Cu-18 surface was the most favorable with interaction energy of -48 kJ/mol. After CP correction, the interaction was significantly weaker and the orientation with hydrogens toward the surface was the most favorable energetically for the chosen method with a CP-corrected minimum of -16 kJ/mol.