HAWAII FLOW REPORT
Last Updated: January 1, 2026
Unfortunately, I do not have access to external databases or the ability to pull in dynamic datasets, including the specific streamflow data for Hawaii that you are referring to. However, I can create a hypothetical scientific streamflow and river report based on what such a report might typically include, assuming there were data points indicating various conditions.
In the state of Hawaii, the streamflow conditions exhibit seasonal variability influenced by the islands' unique climatic patterns. This year, the islands have witnessed fluctuations in river flows, with some rivers experiencing higher-than-average streamflow rates, particularly on the windward sides where rainfall is more abundant. Notably, the Wailuku River on the Big Island has seen increased streamflows, reaching up to 800 cubic feet per second (cfs), which suggests a potential for minor flooding in the surrounding areas of Hilo. Water enthusiasts and residents are advised to exercise caution around such rivers, especially during heavy rainfall episodes that could further elevate flow rates.
During the drier season, several water streams, including those in the leeward regions, have encountered flow droughts, dropping below historical averages. The islands' whitewater trails, popular among kayakers and rafters, have experienced varying conditions; some have seen reduced flows making navigation challenging, while others, such as those along the East Maui Watershed, have maintained sufficient flow due to consistent precipitation in those areas. The Hanalei River on Kauai, a favorite among paddlers, recently recorded a substantial flow increase to 1,200 cfs after a tropical storm, requiring alertness for any potential water-level rise that might affect adjacent towns and agricultural lands. Local agencies continue to monitor streamflows closely to provide timely updates for all water-related activities and safety advisories.
Hawaii's hydrology is characterized by limited surface water due to high evapotranspiration rates and steep topography. Major surface flows include the Wailuku, Wailoa, and Kailua streams on the island of Hawaii, and the Hanalei and Wailua rivers on Kauai. The state has several reservoirs and dams, with the largest being the Kaloko Reservoir on Kauai. Hawaii's climate is tropical, with rainfall varying greatly across the islands and between seasons. The leeward sides of the islands are generally dry, while the windward sides receive more moisture. Watershed health is crucial to maintain water quality and quantity, with some watersheds experiencing degradation due to land use changes and invasive species. Snowpack is not relevant to hydrology in Hawaii due to its location in the tropics.
Winter Storm Warnings
January 1 2026
Residents and visitors across Hawaii are advised to exercise caution due to minor coastal flooding affecting all islands through late Friday night, January 3rd. The National Weather Service in Honolulu has issued a Coastal Flood Statement, warning of high tides combined with water levels running higher than predicted, leading to flooding along shorelines and in low-lying coastal areas. Areas most likely to be impacted include vulnerable coastal roadways, docks, boat ramps, and other coastal infrastructure. Expect flooding of normally dry beaches, minor coastal erosion, and saltwater inundation. It is especially important to stay informed of tide times, as flooding is most likely to occur a couple of hours after midnight. Residents in affected areas should prepare for these conditions and avoid coastal areas during high tides.