The first part of two-series paper deals with quantitative aspects of groundwater problems in the United States of America. As a basis of further discussion, groundwater regions and water use are briefly reviewed. Problems due to groundwater decline such as occurrences of earth fissures or faults and sinkholes, saline water intrusion, and effects on agriculture are introduced and discussed by latest literatures and experiences. Main topics are effects of water-level decline on agriculture in High Plains, problems and management of groundwater in the State of Arizona, and ocurrences of sinkholes in the eastern States. Qualitative aspects will be discussed in the next paper.
