Essential Components of Water-Level Monitoring Programs
Selection of Observation Wells
Frequency of Water-Level Measurements
Uses and Importance of Long-Term Water-Level Data
Ground-Water Development in the High Plains and Gulf Coastal Plain
The Gulf Coastal Plain Aquifer System
Changes in Regional Ground-Water Flow
Drought Monitoring in Pennsylvania
Estimation of High Ground-Water Levels in Massachusetts and Rhode Island
Ground-Water and Surface-Water Interaction in Oregon
Relevance of Water-Level Data to Ground-Water Quality Issues
Saline Water Intrusion in New Jersey
Upwelling of Saline Water in Utah
Effects of Residential Development in Montana
Innovative and Emerging Applications
Status of Water-Level Data-Collection Programs
Challenges and Future Opportunities
Box A—Hydraulic Head and Factors Causing Changes in Ground-Water Levels
Box B—Ground-Water-Level Measurements: Why the Choice of Frequency Matters
Box C—Statistical Design of Water-Level Monitoring Networks
Box D—Ground-Water-Level Monitoring in the 1930’s, 1950’s, and Today