Agriculture remains the backbone of Vijayanagara District’s economy, supporting a substantial proportion of its rural populace. However, agricultural productivity is heavily contingent upon water availability, making irrigation infrastructure a pivotal driver of regional rural transformation and economic stability. This paper investigates the empirical impact of diverse irrigation facilities, specifically surface canal networks linked to the Tungabhadra River basin, borewells, and traditional tanks on agricultural productivity, cropping intensity, and farm income levels across Vijayanagara District. Utilising secondary panel data spanning 2014–15 to 2024–25 collected from the Directorate of Economics and Statistics, District Statistical Office, and Water Resources Department, alongside primary sample data from 240 farm households, this study evaluates spatial variations in land productivity across irrigated and rainfed farming regimes. Employing descriptive statistics, cropping intensity indexes, and a Cobb-Douglas production function, the empirical findings demonstrate that irrigated farms achieve a significantly higher cropping intensity (182.4%) compared to rainfed plots (112.6%). Furthermore, surface canal irrigation increases paddy and sugarcane yields by 42.5% and 38.1%, respectively, while groundwater irrigation through borewells stabilises maize and horticultural crop outputs. Regression estimates indicate an elasticity of output with respect to irrigated area of 0.38, underscoring the critical role of water security. Nevertheless, severe regional disparities persist, with northern canal-fed taluks (e.g., Hospet, Siruguppa boundary areas) outperforming southern rainfed zones (e.g., Harapanahalli, Kudligi), where over-reliance on declining groundwater tables creates long-term ecological and financial vulnerabilities. The paper concludes with strategic policy recommendations focused on expanding micro-irrigation (drip and sprinkler systems), rejuvenating minor irrigation tanks, participatory water management, and balanced regional infrastructure planning.