Waimanalo Watershed Restoration Project
View of the misty Koolau Mountains
The Waimanalo area is truly one of the most beautiful spots on Oahu, with a rural atmosphere comprised of nurseries, small fruit and vegetable farms, and horse boarding facilities. The Waimanalo Watershed is part of the Ko'olaupoko watersheds on the Windward side of Oahu. The Watershed is approximately 3800 acres in size and includes the Waimanalo and Kahawai Streams.
Studies conducted in 1999-2000 showed high levels of nutrients and sediments in the stream. Further studies resulted in the Waimanalo Watershed being listed in the 2004 Final Report of Impaired Waters in Hawaii prepared under the Clean Water Act 303(d) report for excess nutrients, turbidity and suspended solids. The reports do not disaggregate nutrient or sediment sources by land type, land use, or tributary.
O'ahu RC&D is working with landowners and other partners to reduce nutrients, erosion and sediment delivery in the Waimanalo Watershed mauka of Kalanianaole Hwy. Surveying and water sampling throughout sections of the watershed will help provide direction on potential pollutant sources, and focus land treatments for farms, homes, roads, and streams. Utilizing the best conservation planning concepts, farmers can receive financial support to install buffers, vegetative barriers and other practices to reduce soil erosion.
Generous support for this project comes from the Clean Water Act and the Hawaii Department of Health.