Water security in the Karuvannur watershed was assessed by looking at the availability of blue and green water separately. Blue water (surface and groundwater) is more secure than green water (rainwater stored in soil). The study found that both types of water are currently secure, but green water is less so. This means that more efforts should be made to conserve green water in the area. As water scarcity is increasing, it is important to take strict measures for water conservation to ensure sustainable water security in the future.