The practice of continuous flooding of rice fields in the national irrigation systems has attendant issues, including the inefficient use of water, unequal distribution of water along the irrigation canals, and greenhouse gas emissions. An ex-ante analysis was conducted to evaluate alternative policy options in the Upper Pampanga River Integrated Irrigation Systems, using both market and non-market approaches. The market approach estimated the greenhouse gas avoided and water savings due to the shift in policy. The non-market approach used choice experiment to estimate willingness to pay of farmers to shift the current to an alternative policy. The study concludes that there is room for a policy change that addresses greenhouse gas emissions from rice cultivation. This is indicated by the farmers’ willingness to pay for this policy change. The important consideration, however, is that the policies should address factors including water availability, greenhouse gas reduction potential of the technology or water system being promoted by the policy, and the irrigation water price which should be lower than the current irrigation service fee to serve as incentive to policy adoption.