The International Commission on Large Dams groups National Committees which are organized in countries wishing to become member. The Commission is directed by :
- The General Assembly consisting of representatives from all the Member Countries and of the Officers of the Commission. The meeting is held during the Annual Meeting. Any independent country can become a "Member Country" and constitute a National Committee consisting of persons competent in the matters relating to dams. The General Assembly is in charge of resolving all questions concerning organisation and direction of studies, investigations and experiments, administration of all funds and properties, operation of the Central Office and any other relevant business of the Commission ; it shall approve the budget of receipts and expenditure, appoint and organise all Committees, and elect new Member Countries.