Any geographical area independently administered by a sovereign government and interested to participate in the Commission's activities to work together towards a water-efficient management system is eligible to become a National Committee (NC). The Commission advocates for the National Committees to be broad-based multi-disciplinary and should provide a platform for further collaborations with different sectors and relevant institutions with the parallel aim of a water-secure world. 

The membership of the Commission consists of governments, professionals, planners,  policymakers, water managers, irrigation and agriculture engineers, research scientists and educationists; engaged in irrigation, drainage, flood control, agricultural water management and related areas within the countries through their National Committees (NC) traditionally organized under the respective government departments responsible for irrigation and agricultural water management.

Currently, the ICID country membership network spans 110 countries, and one Committee across Africa, the Americas, Asia, Oceania, and Europe, encompassing over 95% of the world's irrigated area. This includes 44 Active Member Countries plus one Committee, and 66 Associate Member Countries, totalling 111 countries.