Only five Hawaiian Islands (Kaua‘i, O‘ahu, Moloka‘i, Maui, and Hawai‘i) are high enough to capture the rain clouds brought to the islands by the prevailing northeast trade winds and for the resulting orographic (generated by the mountain) rainfall to generate streams. These 376 small, torrential mountain streams are located on the windward side of the islands and represent the freshwater ecosystem that is home to Hawaii’s native stream animals.

Hawaiian streams have only five native species of fishes, two species of crustacean, and three species of mollusk. Hawaiian native stream life, like the native Hawaiian people who depended on the streams, embody the connection of Mauka (mountain) to Makai (ocean) that defines the Hawaiian ecosystem.

Hawaii has approximately 3,905 miles of river, but no designated wild and scenic rivers.