Irrigation plays a significant role in enhancing agricultural output by providing water to crops, especially in regions where rainfall alone is not sufficient for optimal growth. This study aimed to evaluate the response of land use/land cover dynamics to stream flow and seasonal irrigation water availability using remote sensing and modeling techniques. Surface water availability was assessed in the Robi watershed using the SWAT model. The model's performance was evaluated by comparing measured and simulated streamflow, with good agreement observed for the calibration and validation years. The coefficient of determination (R2) values ranged from 0.69 to 0.83, Nash-Sutcliffe efficiency (NSE) values ranged from 0.66 to 0.81, and Percent bias (PBIAS) values ranged from -0.041 to -0.01. Various factors, including the expansion of residential areas, deforestation, and increased agricultural land, influenced the resource bases in the Robi watershed, indicating land use/land cover changes. Land use/land cover classification accuracy assessments were done by using GIS and Google Earth. The overall accuracy ranges from 91.1% to 93.6% and a kappa index agreement (K) from 88.82% to 91.12% for the years 1990, 2001, 2010, and 2019. These changes in land use/land cover had a significant impact on watershed hydrology. Analysis of stream flow components showed an increasing trend in surface runoff by 9.29 mm over time, while lateral soil flow and ground lateral flow experienced slight decreases of -5.42 mm and -5.98 mm, respectively. During the dry season, water flow exhibited a decline, indicating reduced water availability with a total decrease of 5.76 m3/sec over the entire period. The availability of surface water is determined by evaluating land suitability and calculating gross irrigation water requirements. Land suitability assessment considers factors such as soil, land use, river proximity, urban proximity, road proximity, rainfall suitability, and slope. The Analytic Hierarchy Process (AHP) method assigns weights to these factors. The CROPWAT model calculates the gross irrigation water requirement, with a total gross irrigation demand of 28.96 m3/s. However, an imbalance is observed between the available stream flow (13.18 m3/s) and the gross irrigation demands of selected crops. Key Words: land suitability, Crop water requirement, Arc GIS, Arc SWAT, CROPWAT. Stream flow, Land use land cover change, Surface Irrigation.