Hawaii
Watershed Hydrology
The Hawaii Watershed (HUC 20010000) covers a total land area of 1,408 square miles and is characterized by its unique hydrological features. The watershed receives an average annual rainfall of 175 inches, which is mostly concentrated in the winter months. The watershed is home to several important river systems, including the Wailuku, Waikolu, and Honopou streams. Snowpack is not a significant factor in the Hawaii Watershed due to its tropical climate. Surface water in the watershed is used for irrigation and energy production. The major reservoirs in the watershed are the Wailoa River State Recreation Area and the Kokee State Park. The constituents of the reservoirs include sediment, nutrients, and organic matter. The climate of the Hawaii Watershed is characterized by high temperatures, high humidity, and frequent rainfall. Climate trends show increasing temperatures and decreasing rainfall in recent decades, which may have implications for water availability in the future.