The Okavango Basin is a large watershed in southern Africa that empties into the Okavango Delta, which is an inland delta that spreads out onto the Kalahari sands of Botswana. Hydrologic and ecological models are being used in the area to create environmental flows as well as explore development and climate change scenarios. The uncertainty in these models is inherent. However, their usefulness can be evaluated through sensitivity and uncertainty analysis (SA/UA). Uncertainty analysis is useful for measuring model reliability and sensitivity analysis apportions the total model uncertainty to individual inputs and processes. This work is threefold involving a SA/UA on two existing hydrologic models in the area (the Pitman rainfall runoff model in the basin and the ORI reservoir model in the Delta) as well as the development and analysis of a fish population model for the Okavango Delta based on the annual flood pulse that the Delta receives. Keywords: botswana, delta, fish, hydrologic, hydrology, model, modeling, okavango, sensitivity, uncertainty, watershed, Agricultural and Biological Engineering.