For the gauge of land suitability for crops, runoff plays a vital role. Runoff is an important parameter for estimating irrigation management as it effects the water scarcity index and irrigation water requirement. Interpretation of rainfall and runoff is very important to assay the water availability. In the present work, the surface runoff has been estimated for the watershed under Nagamangala taluk in Hemavathi command area. The daily runoff from the watershed for 12 years, i.e., 2011–2022 has been estimated. The maximum rainfall was 1919.7 mm in 2022 for Basaralu and minimum rainfall was 207.9 mm in 2012 in Devalapura. It has been ascertained that that maximum runoff is 690.30 mm in 2022 year for Basaralu station, while the minimum runoff is 4.34 mm in 2012 year for Devalapura due to the change in the intensity of rainfall. Curve Number methods is widely used for determining the runoff and SCS–CN method is helpful for the estimation of runoff for better management of irrigation projects.