  Charge ordering in doped \cob planes near the commensurate fillings $x =
{1/4}$ and 1/3 are considered for $Na_x CoO_2.yH_2O$ and suggested to be
competitors to superconductivity, leading to the experimentally seen narrow
superconducting dome bounded by commensurate doping: ${1/4}<x< {1/3}$.
Intercalated hydrogen bonded $H_2O$ network, by its enhanced dielectric
constant, screen and frustrate local {\em charge order condensation energy} and
replace a generic `charge glass order' by superconductivity in the dome. An
access to superconductivity and charge order, available through the new water
channel, is used to predict novel effects such as `Electrical Modulation of
Superconductivity' and `Electroresistance Effect'.
