In arid and semi-arid areas water management is essential for maintaining a sufficient and dependable water supply. As India has uneven distribution of rainfall and also due to climate change the rainfall pattern is greatly affected. As results many places in India suffers from water scarcity issues. Hence, it is more important to have the correlation between water available and its consumptive use. Therefore, this study is devoted to estimate the water available in the Darewadi basin and its usage. To achieve the defined goal this study engages two powerful tools namely SWAT (Soil and Water Assessment Tool) and Modified Penman Method (MPM). To process the SWAT model, the meteorological data from IMD Pune was used for period (2000–2020). The SWAT model is calibrated and validated using SUFI-II algorithm in SWAT-CUP. The methodology was adopted as, MPM results and the actual evapotranspiration values obtained from the SWAT model were compared. The findings indicate that the average curve number for study area is 79, and evapotranspiration was 561 mm. The maximum crop water demand was observed at 2009 and it was 561 mm, similarly water yield for year 2009 is 457.39 mm and Precipitation for year 2009 was 470.2 mm. Additionally, it was found that the research area experiences salinization since the rate of evaporation is higher than the rate of precipitation. This study helps with future water demand predictions and management, as well as the identification of potentially salinized areas. The study’s conclusions can be used by researchers and decision makers to manage and distribute water resources in a sustainable way.