Runoff performs a vital part of the water cycle by returning surplus rainfall to the lakes, rivers, and oceans. It regulates the flow of storm water into channel networks. Modeling of runoff can ensure monitoring, understanding, and managing both the quality & quantity of aqua resources. Rainfall-runoff models are often characterized by their spatial processes and model structure. The model structures are based on the governing equations. A model used to specify relation between rainfall and runoff can be categorized into empirical, conceptual, and physical frameworks. The assessment of rainfall and runoff in any watershed plays a crucial role in the development of water management systems. This research aims to establish a rainfall-runoff model for the watershed. The amount of runoff in terms of depth is estimated from the catchment by the Soil Conservation Service Curve Number (SCS-CN) approach. The SCS-CN method is integrated into remote sensing (RS) and geographic information system (GIS) technology to determine the runoff efficiently. This investigation revealed that the watershed of the Upper Lake produces runoff as 6090.4 mm for rainfall of 7062.09 mm in the subjected period.