The indigenous fresh water management technologies of Truk, Pohnpei, and Kosrae, the Federated States of Micronesia, and of Guam, a U.S. Territory in the Mariana Islands, were investigated at the reconnaissance level through a combination of archaeological and ethnographic field methods and library research. More intensive field studies in the coral islands and remote parts of the high islands of the Carolines can yield additional information on native fresh water management which can help guide the introduction of appropriate modern technologies.

It was found that a well-developed series of indigenous techniques for managing fresh water for domestic uses and in agriculture once existed on all the islands studied. These include provision of clean drinking water by various rainwater catchment devices, and by the development of shallow wells, seeps and springs. Freshets emerging from the sand were sources of bathing water at low tide in some settings. Where surface water is abundant, such as on Truk, Pohnpei and Kosrae, streams and rivers were used for both drinking water and bathing. Where surface water is less abundant, such as on Guam and the atolls of Namoluk and Ant, rainwater catchment for rainwater was preferred over groundwater for drinking. Boundary channels within the large interior taro patches of Namoluk Atoll provided drinking and bathing water. Large canals occasionally were dug to drain these taro patches of salt water after typhoon-related flooding. In addition to technical documentation, customs and folklore related to the origins and socially appropriate uses of fresh water were recorded.

Fresh water management in high island agriculture included the construction of stone retaining walls, elevated garden plots, and dirt- and rock-lined channels to prevent soil loss during intense tropical storms. In Namoluk Atoll perimeter channels were built around smaller taro patches to drain excess runoff. Natural seepage in upland settings (Pohnpei) and fluvial flows and freshets within mangroves (Kosrae) were used in the production of fermented breadfruit in underground storage pits. As modern technologies replace indigenous ones, especially the use of ferro-cement catchment tanks in Namoluk and piped water systems on the high islands, customary water management practices related to drinking and bathing are rapidly disappearing. However, native agricultural uses and management of fresh water are still common in the high islands studied except Guam, where subsistence farming has all but disappeared.