Kaua‘i Watershed Alliance

Island of Kaua‘i

Kauai's rugged mountains intercept moist trade winds, producing a bounty of rain that replenishes the island's streams and aquifers. The summit region near Wai'ale'ale, arguably the wettest spot on earth, sits at the head of island's five largest aquifers, and the surrounding watershed is home to thousands of native plants, birds, snails, insects, and other invertebrates that comprise Kauai's famed biodiversity.

In 2003, nine state and private landowners, and the Kaua'i County Board of Water Supply, joined forces and formed the Kaua'i Watershed Alliance (KWA). The Conservancy's Kaua'i Program was contracted by the KWA to write a watershed management plan, which was completed in April, 2005.

TNC is now coordinating the implementation of an overall management strategy, detailed in the plan, to protect the 144,004 acres of partnership lands.

Our Approach

As the oldest and most remote of the populated Hawaiian Islands, Kauai's native ecosystems are distinct and within  the mountain watershed they remain largely intact. Remarkable examples of native lowland forest, rarely found elsewhere in the islands, can still be found in the remote windward valleys. Kaua`i has the highest combined number  of Hawaiian endemic plants, birds, insects, and natural communities of all the native-dominated landscapes in the state.

The montane wet forest ecosystem captures the majority of the rainfall and contains the majority of Kauai's endemic species. Preserving the health of these native ecosystems is essential to maintaining the island's biodiversity and hydrologic function.                                                                                                    


The partners, whose public and private land holdings lie within the forest reserve boundary, recognize that continuing cooperation is the key to a successful watershed management program that will safeguard this region from invasive alien plants, animals, and other threats. The members have different interests, priorities, and constituencies, but all share a common commitment to the long-term protection of Kauai's core watershed areas.

How the Partnership Will Help the Watershed

The Alliance management plan stresses the importance of active watershed management and targets Kauai's high elevation rain forests as the top priority for protection, in particular, the forests that lie within its central plateau. The 12,000-acre plateau provides a substantial portion of the island's groundwater and stream flow. 

Highest priority was given to programs systematically addressing ungulate and weed control, two critical threats. Reducing the impact of these threats across the watershed is of primary importance to the continued health of the island's water supply, and the survival of Kauai's biological treasures.


Partnership projects currently underway include comprehensive aerial weed mapping and removal of alien species from  the Alaka`i Plateau, a mile-high plateau cradled between the mountains and the upper portions of Lumahai and Wainiha Valleys. This wilderness is a haven for rare native birds and plants, many of them endangered.  

  • Ben A. Dyre Family Limited Partnership
  • Department of Water of the County of Kaua`i
  • Grove Farm Company, Incorporated
  • Kamehameha Schools
  • Kaua`i Ranch, LLC
  • Līhu`e Land Company
  • McBryde Sugar Company, Ltd.
  • Namahana Farms
  • National Tropical Botanical Garden
  • Princeville Development, LLC
  • State Department of Land and Natural Resources 


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