The stream systems of Hawai‘i are unique and home to many rare species, including five native fish and five native shellfish. These native species have amphidromous life cycles, meaning that they spend part of their lives in the ocean and part in freshwater streams. Stream flow serves as a vital natural pathway, connecting saltwater and freshwater habitats so that these animals can migrate between them and carry out critical life stages (e.g., development, reproduction). Over the last 20 years, the amount of rainfall in Hawai‘i has decreased, and climate models predict that this trend will continue. It is uncertain how reduced rainfall will affect stream flow and, consequently, the native stream species that depend on it. This study will advance our understanding of what climate change means for stream flow and native stream species in Hawai‘i. Such information can be used to inform conservation management decision making.