Water quantity and quality at surface water supply intakes are of serious concern nationwide. Existing studies have focused on characterization and assessment of public water supplies. However, there exists no research on evaluation of water quantity and quality at surface water supply intakes, and development of comprehensive watershed modeling tools to do so. Furthermore, no existing model is capable of comprehensively simulating all of the hydrologic, upland soil and streambank erosion, sediment transport, and fate and transport of nutrient and pesticide processes necessary to comprehensively assess the water quantity and quality problems and help make the best management decisions to eliminate or minimize those problems.