Thesis (Ph.D., Biological & Agricultural Engineering) -- University of Idaho, 2016 | Water management from energy production to aquatic habitat quality assessment uses integrated hydrological modeling to predict water quantity, temperature and timing by linking meteorological inputs with physical hydrological processes. In mountainous watersheds, accurate estimation of snow accumulation and ablation is required for modeling in addition to hydro-meteorological and geological processes that are calculated for rain dominated watersheds, which adds more complexity to modeling. In such frameworks, the use of fine spatial and temporal resolutions of meteorological inputs substantially increases modeling costs. However, using coarse resolution inputs reduces modeling costs in expense of prediction accuracy due to loss of information. This work focuses on the information lost and transferred by coarsening resolution of input distribution. The analyses show the scale dependence of topography-induced heterogeneity on meteorological and energy exchange variables and its consequent effects on hydrological modeling accuracy on both snow water input, stream flow and stream water temperature.