Northern Guam geospatial information server
Water pathways in the Northern Guam Lens Aquifer
The NGLA is recharged by rainwater that makes its way down through the rocks to become groundwater. When it rains, most of the water in northern Guam falls directly on the limestone surface. Part of it evaporates back into the atmosphere, and part percolates downward into the ground. This is called autogenic recharge because the surface of the aquifer itself captures recharge water.