The presentation will provide overview of an ongoing study that includes: (i) effect of landuse change on temperature and precipitaiton records; (ii) performance of 15 different ET schemes as driven by month long meteorological inputs; and (iii) uncertainty in the water resource decisions based on the input of climate change and model parameterizations. Results indicate that there are significant changes in the precipitation fields due to regional changes in monitoring locations and significant changes in the temperature fields due to microscale changes in the sites. There are significant differences in the ET estimates depending on the the parameterization being used. No clear conclusion regarding whether a more complicated scheme performs better can be made from our results, and the errors and uncertainty in the input appears to be the dominant error term.