During 2007-2008, the United States Bureau of Reclamation used ground-based instrumentation to assess evapotranspiration of riparian vegetation in the Cibola Wildlife Refuge of Arizona. Data gathered from three Bowen Ratio towers and one Eddy Covariance tower was analysed. The eddy flux estimation from eddy covariance data involved various corrections in the raw data. These estimates were used to compute the daily evapotranspiration. Evapotranspiration estimates from both approaches were compared. A methodology for generating continuous daily evapotranspiration estimates using Artificial Neural Network technique was discussed. These groundtruth estimates were compared to the values from the remote sensing algorithm.