Northern Guam geospatial information server
About this map:
This map shows the elevation contours of the water table in northern Guam, as understood by the comprehensive topographic survey and water level measurements from more than 70 municipal water production wells in April 1982, in the middle of Guam’s dry season. (March and April are the two driest months of the year.) Spatially variable seasonal fluctuations that range from a few cm to 10s of cm reflect spatial variations in bedrock permeability. Water levels across the basal zone show a direct, virtually one-to-one, response to long-periodicity sea-level variations on the order of 10s of cm, such as are associated with ENSO events. Information used in this map was scanned from chapter IV, "Hydrogeology," Figure 4-3, in Barrett Harris and Associates with Camp Dress McKee (1982), Aquifer Yield Report, Northern Guam Lens Study, prepared for Guam Environmental Protection Agency, and was georeferenced and digitized on-screen.