  There is a growing interest in very long baseline neutrino oscillation
experimentation using accelerator produced neutrino beam as a machinery to
probe the last three unmeasured neutrino oscillation parameters: the mixing
angle theta_13, the possible CP violating phase delta_CP and the mass
hierarchy, namely, the sign of delta-m^2_32. Water Cherenkov detectors such as
IMB, Kamiokande and Super-Kamiokande have shown to be very successful at
detecting neutrino interactions. Scaling up this technology may continue to
provide the required performance for the next generation of experiments. This
report presents the latest effort to demonstrate that a next generation (> 100
kton) water Cherenkov detector can be used effectively for the rather difficult
task of detecting nu_e events from the neutrino oscillation nu_mu -> nu_e
despite the large expected potential background resulting from pi^0 events
produced via neutral current interactions.
