Fractional linear polarization as a function of T_bΔΩ for the 183 GHz, 3₁₃−2₂₀ (top), and the 325 GHz, 5₁₅−4₂₂ (bottom) H₂O rotational transitions, both within the ground-vibrational level, for four values of the angle between the magnetic field lines and the direction of propagation of the maser radiation, θ. We considered the magnetic field strength and decay rate listed in Table 3 for H₂O. Positive and negative p_L values mean that the vector of polarization is either perpendicular or parallel the magnetic field lines projected on the plane of the sky. The vertical line sets the T_bΔΩ value such that gΩ = 10R.