Planning and managing water resources effectively requires accurate streamflow models. In the Middle Tapi Basin of India, this work focuses on evaluating the efficacy of streamflow modelling using single-site as well as multi-site methodologies of calibration. The SWAT model is employed for the simulation of flow in the study region. Calibration at the basin outlet and single-site have been used earlier. For this purpose, this paper explains a multisite calibration technique from a new perspective, considering the geographic variability of the watershed characteristics. The Middle Tapi Basin consists of prevailing different conditions of hydrology. The calibration of the model was considered in three streamflow measuring stations, Sangkheda, Ukai, and Gidhade, respectively. The statistics that define its performance for the calibration phase include R2, NSE, and PBIAS. These are the results of the multi-site calibration runs to examine the effectiveness of the Ukai model. The performance of the Ukai model had slightly improved; for example, Gidhade and Sarangkheda exhibit better performance than in the past. In these works, great emphasis is made on the requirements of calibration regarding a large-scale basin to consider regional differences in watershed features. This usually tends to improve the accuracy of the streamflow models in the multi-site calibration method and thus lowers the level of uncertainty in the hydrologic forecasts. The results will give a useful guideline for water resources managers and hydrological modelers in the selection of an approach to calibration that seems more desirable. This consideration of regional heterogeneity through the multi-site calibration approach would, therefore, be of more benefit in water resource planning and management as it could result in more accurate hydrological projections within the Middle Tapi Basin.