Island Groundwater
Resources Research
Federated States of Micronesia

The two major sources of water supply in the atoll islands and many rural areas of the high islands of the Federated States of Micronesia (F.S.M.) are rooftop rainfall catchment systems (RRCS) and shallow groundwater sources. The rain catchment systems are best suited for supplying drinking water needs. Other water demands are best met from groundwater sources. An ideal water supply system would have the components of the RRCS and the groundwater components sized in such a manner to meet the needs of the individual family that owns the system.

Guam relies on groundwater for about 80% of its drinking water production to support 150,000 permanent residents and a rapidly growing tourism industry that serves over 1,000,000 tourists each year. Guam’s principal aquifer, the Northern Guam Lens Aquifer, is tapped by over 100 municipal wells producing over 30 mgd, about half of the current estimated sustainable yield.