American Samoa Watershed Study

Study Area

American Samoa is an unincorporated territory of the United States located in the mid-South Pacific Ocean, a part of the Samoan Islands archipelago in Polynesia American Samoa consists of 70 villages across five main islands (Tutuila, Aunuu, Ofu, Olosega, and Tau), a smaller privately owned island (Swains Island), and one coral atoll (Rose Atoll). Tutuila is the largest and most populous island, with a 58 square mile land area and approximately 48,000 residents. Aunu’u Island is 0.59 square miles and located one mile southeast of Tutuila, with less than 450 residents. The islands of Ofu, Olosega, and Tau are collectively referred to as the Manu’a Islands and are 2.8 square miles, 2.0 square miles, and 6.5 square miles respectively. They have a combined population of 850 and are located approximately 70 miles east of Tutuila.

Due to the steep terrain of the islands, most development, including critical infrastructure such as the Lyndon B. Johnson (LBJ) Tropical Medical Center, the primary petroleum tank farm, and the primary roads are located along narrow areas between the mountains and the shoreline. Even Pago Pago harbor, which is central to the economy of American Samoa, is built within very limited space between steep slopes and the coast. The Tafuna-Leone Plain on the southwestern area of Tutuila is the largest relatively flat area of all the islands and subsequently is the largest area of development.

Shared Vision

Natural hazards including tropical cyclones, flooding, shoreline erosion, landslides, and tsunamis negatively impact communities, the environment, and the economy in American Samoa. Many of these hazards are expected to intensify with climate change. A collaborative systems approach between stakeholders is needed to address these interrelated issues, improve watershed management, and support community resilience.

Contact Information

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Submit Public Scoping Comment (12/12/22 – 1/11/23)