This paper studies single-molecule and collective dynamics of water confined in protein powders by means of molecular dynamics simulations. The single particle dynamics show a modest retardation compared to the bulk but become highly stretched in the powder, with the stretching exponent of similar or equal to 0.2. The collective dynamics of the total water dipole are affected by intermolecular correlations inside water and by cross-correlations between the water and the protein. The dielectric spectrum of water in the powder has two nearly equal-amplitude peaks: a Debye peak with similar or equal to 16 ps relaxation time and a highly stretched peak with the relaxation time of similar or equal to 13 ns and a stretching exponent of similar or equal to 0.12. The slower relaxation component is not seen in the single-molecule correlation functions and can be assigned to elastic protein motions displacing water in the powder. The loss spectrum of the intermediate scattering function reported by neutron-scattering experiments is also highly stretched, with the high-frequency wing scaling according to a power law. Translational dynamics can become much slower in the powder than in the bulk but are overshadowed by the rotational loss in the overall loss spectrum of neutron scattering.