Enhancing water productivity is often recommended as a "soft option" in addressing the problem of increasing water scarcity. In this study, authors analysed the water productivity and GHG implications of water reuse through pumping groundwater and creek water, and compare this with gravity-fed canal irrigation in the Upper Pampanga River Integrated Irrigation System (UPRIIS) in the Philippines. Water productivity indicators show that water reuse contributes significantly to water productivity. For example, water productivity with respect to gross inflow (WPgross) with water reuse (0.19 kg grain/m3) is 21% higher than without water reuse (0.15 kg grain/m3). However, there is a tradeoff between increasing water productivity and water reuse as water reuse increases GHG emissions. The estimated GHG emission from water reuse (pumping irrigation) is 1.47 times higher than without water reuse (gravity-fed canal irrigation).