Starting about 500 years ago, early Hawaiians used the Kawainui wetland as a fishpond and to grow taro. Dryland crops around the wetland at the time of the Great Mahele included sweet potatoes, gourds, wauke (paper mulberry for making kapa), ‘awa (kava), pia (arrowroot for starch), bananas and sugar cane. (Drigot)
Rice was cultivated from the 1850s to the 1920s and then ranching and grazing became the predominant uses. (Ramsar Wetlands Information Sheet)
In the Māhele, Queen Kalama, Kamehameha III’s wife, received land within the area in and around Kawai Nui. The land ownership changes which occurred to Queen Kalama’s ownership of the ‘ili of Kawai Nui mirrored the land use changes in general both in the region and in the islands as a whole.
Then, this area encompassing much of the Kailua ahupua‘a, was inherited by her stepfather and uncle. He promptly sold it in 1871 to a haole, Charles Coffin Harris, an American lawyer, who had by that time consolidated claim to the ahupua‘a of Kāne‘ohe as well as that of Kailua.
One of his children, Nannie Roberta Harris, became sole heir to the Harris estate, including the Kailua ahupua‘a at that time. She owned the Kailua ahupua‘a until 1917 when she and her husband sold nearly all of their interest in both Kailua and Kāne‘ohe to
Harold KL Castle. (Drigot)
When I was a kid, we referred to this area as the “swamp” – many of the old maps referred to it as such. Auto parts shops lined the road at its edge; the dump was nearby.
Kawainui is the largest remaining wetland in Hawai‘i, encompassing approximately 830 acres of land in Kailua, Oahu. It provides important habitat for waterbirds and migratory bird species. (Kawai Nui Marsh Master Plan, 1994; Army Corps)
When it rained hard, there were flood issues … “Damage to private dwellings, farms and property in Kailua was caused today by flood waters backing up from the swamp land in the Coconut Grove area. Residents said water was more than three feet deep in some places and was rising.” (Star Bulletin, Mary 13, 1940)
Flooding was not the only local concern … “We want to eliminate the mosquito problem and we want to reclaim the area, if possible.” (Castle; Drigot)
As late as 1956, the Kaneohe Ranch had installed a vertical pump and began pumping with such energy that, four months later, the water table of the Marsh had dropped “almost four feet and made the once forbidding marsh a lush grazing land”. (Drigot)
A stream runs through Oneawa ‘ili to the sea, providing a natural drainage for the Kawainui marsh. The Oneawa Canal (Kawainui Canal, former approximate location of Kawainui Stream) was constructed in the 1950s to provide flood control and stability for real estate development. (Dye)
The Oneawa Canal connects Kawainui Marsh to Kailua Bay, is 9,470 feet long, and is located at the northeast corner of Kawainui Marsh. The upper streams and surface water stored in the marsh are freshwater, while the salinity of water within Oneawa Canal is brackish and tidally influenced. (Army Corps)
“Even though the Oneawa Channel (Kawainui Canal) was constructed in 1950 to prevent the major flooding of the Kailua residential area situated on the edge of the marsh, five subsequent severe floods occured in 1951, 1956, 1958, 1961 and 1963.” (Drigot)
“In 1964, after a two year intense battle for development rights to the central portion of Kawainui Marsh, Centex-Trousdale Construction Co. surrendered its claim and the City of Honolulu emerged victorious in its seven-year battle to acquire 749 acres of the Marsh for flood control and park purposes when, with federal assistance, they purchased the Centex-Trousdale properties”. (Drigot)
Then, they built a levee … “Construction of the original Kawai Nui Marsh Flood Control Project was authorized by the Flood Control Act of 1950 and was completed in August 1966 by the Corps. Project features included … a 6,850-foot-long earthen levee with a maximum crest elevation of 9.5 feet; a 50-foot-long stub groin and 50-foot-long revetment at the outlet of Oneawa Channel”. (Army Corps)
Over the years, vegetation within the marsh created a dense mat that affected the hydraulics of the marsh causing the project to be overtopped during the January 1988 storm.
“From December 31, 1987 through January 1, 1988, severe flooding of the Coconut Grove community occurred when the water level in the marsh exceeded the crest of the existing levee. Following this storm event, an emergency ditch was excavated alongside the levee to increase outflow from the marsh.” (Army Corps)
The floodwall has a maximum height of four feet and is 6,300 feet long extending from Kailua Road on the south to the Oneawa outlet channel on the north. The levee fills 1.8 acres of wetland fringe and provides a higher level of flood damage reduction to a larger part of Coconut Grove, which has more than 2,000 structures. (Army Corps)
By then, the Kawainui wetland reference had changed from “swamp” to “marsh.” More recently, Kawainui Marsh was recognized as a Ramsar Wetland of International Importance in 2005 for its historical, biological, and cultural significance. (DLNR)
Ramsar is the name of the city in Iran where the Ramsar Convention, or the Convention on Wetlands of International Importance, was signed in 1971 and came into force in 1975.
Ramsar is not an acronym, and the convention is also known as “Ramsar”. The convention’s goals are to stop the loss of wetlands worldwide and to conserve the remaining wetlands through management and use. (Ramsar Convention of Wetlands)
Sacred to Hawaiians, Kawainui Marsh, the largest remaining emergent wetland in Hawaii and Hawai‘i’s largest ancient freshwater fishpond, is located in what was once the center of a caldera of the Ko‘olau shield volcano.
The marsh provides primary habitat for four of Hawai‘i’s endemic and endangered waterbirds (Hawaiian Duck, koloa; Hawaiian Coot (‘alae ke‘oke‘o); Hawaiian Moorhen (‘alae ‘ula) and Hawaiian Stilt (kukuluae‘o (abbreviated as ae‘o)) and contains archaeological and cultural resources, including ancient walled taro lo‘i where fish were also cultivated. (Ramsar)
In addition, the levee has become a pathway that people within the surrounding community use for walking, running and biking. Other recreation includes bird and wildlife watching.
Leave your comment here: