Kawai Nui Marsh
|Official name||Kawainui and Hamakua Marsh Complex|
|Designated||2 February 2005|
|Reference no.||1460 |
Kawai Nui Marsh (or Kawainui) is, at over 800 acres (3.2 km2), the largest wetlands in the Hawaiian Islands. The marsh is located near Kailua on the windward side of O'ahu and is owned by the State of Hawaii and the City & County of Honolulu. 250 acres (1.0 km2) of the land is from a 1968 sale to the City and County of Honolulu by Kaneohe Ranch.  Kawai Nui marsh is a Ramsar Convention wetland site, established in February 2005. 
Kawai nui means "the big water" in Hawaiian and reflects the fact that this feature was a huge, possibly marine or estuarine, body of water at the time when the area was first settled by Polynesians. Today, nearly all of the marsh is covered by plants, and this is either floating on water, growing on a mat of peat that is floating on water, or in the upper-most parts of the marsh a wet meadow. The latter area is utilized by cattle for grazing when not flooded by high water level. Most of the marsh lies behind a levee constructed by the United States Army Corps of Engineers for flood control purposes. The marsh is the lowland recipient of sometimes very heavy rainfall in Maunawili Valley. The marsh outlet is through a man-made channel, Oneawa Channel.
- Kawainui Marsh, Department of Land and Natural Resources Sustainability Hotspot
- Kawai Nui Marsh
- Kawai Nui Heritage Foundation and ‘Ahahui Mālama I Ka Lōkahi. "Na Pohaku o Hauwahine". Ahahui. Honolulu, HI, USA: ‘Ahahui Malama i ka Lokahi. Retrieved May 5, 2012.