In this work, absolute cross sections for the ionization and fragmentation of water vapor molecules are presented, for the ffirst time, for collisions with He(+) with energies of 1.0, 1.5 and 2.0 MeV, total and partial in the pure ionization, electron loss (projectile ionization) and electron capture by the projectile processes. These cross sections were obtained by means of coincidence measurements between the post-collision projectile charge states and the recoil ion charge states, the latter determined by time-of- °ight spectrometry. Both the experimental setup and the methodology for data acquisition are described in detail, together with several procedures that were needed to the completion of this work. The results are, whenever possible, compared with experimental data ob- tained not only in the Van de Graaff Accelerator Laboratory of PUC-Rio, but also from other groups, for the ionization and fragmentation of the water molecule by He(+) and other projectiles, and analyzed in order to better un- derstand the relative importance of the different processes leading to water molecule fragmentation in its transition from the sequential to the explosive regime.