The Wailuku River is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline data
The National Map
, accessed April 28, 2011 water course on the

Island of Hawaii Hawaii ( ; haw, Hawaii ) is the largest island in the United States, located in the state of Hawaii. It is the southeasternmost of the Hawaiian Islands, a chain of volcanic islands in the North Pacific Ocean. With an area of , it has 63% of th ...

in the Hawaiian Islands. It is the longest river in

Hawai'i Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only ...

and the largest in the state by mean discharge. Its course lies mostly along the divide between the

lava flows Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or un ...

of Mauna Kea and those of

Mauna Loa Mauna Loa ( or ; Hawaiian: ; en, Long Mountain) is one of five volcanoes that form the Island of Hawaii in the U.S. state of Hawaii in the Pacific Ocean. The largest subaerial volcano (as opposed to subaqueous volcanoes) in both mass and ...

to the south. It arises at about the elevation along the eastern slope of Mauna Kea (). It flows generally eastward, descending steeply from the mountain and entering the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contin ...

at Hilo.

Wailuku River State Park Wailuku is a census-designated place (CDP) in and county seat of Maui County, Hawaii, United States. The population was 17,697 at the 2020 census. Wailuku is located just west of Kahului, at the mouth of the Iao Valley. In the early 20th centur ...

is located along the lower reach of the river. One section of the park includes Rainbow Falls (), and another section Peepee falls and an area called the Boiling Pots (a series of small falls and pools). However, it is also one of the deadliest bodies of water in the state, as the river is not guarded and can behave unpredictably. BoilingPotsHawaii

The lower reach of the river is used for the generation of

hydroelectricity Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined an ...

. The flow at Hilo averages 275 cubic feet per second (8 m³/s) with peak flows 40 times as great. Water flow is monitored by the USGS. The stream carries an average of 10 tons of suspended sediment into

Hilo Bay Hilo Bay is a large bay located on the eastern coast of the island of Hawaii. Description The modern town of Hilo, Hawaii overlooks Hilo Bay, located at . North of the bay runs the Hamakua Coast on the slopes of Mauna Kea, and south of the ba ...

each day, at . The river has been the site of sewage leaks and is the subject of water quality research. Water advisories are posted online by the State of Hawaii. There is a plan for restoration of the Hilo Bay watershed that includes characterization of the Wailuku River. In the Hawaiian language, ''wai'' means fresh water and ''luku'' means destruction, so it means essentially River of Destruction. The river can rise into the trees and drop back down very fast. The high flood marks can be seen dated in concrete, on the stairs going down to the river behind the Hilo Public Library. According to legend, the river was created in a battle between the god Maui and the lizard monster Kuna. The river is rated Class 5 white water and has been navigated by experts on kayak. USGS

References

External links

USGS flow data
{{authority control Bodies of water of Hawaii (island) Rivers of Hawaii