Hawaii, with its lush landscapes and diverse ecosystems, relies on its water resources for agriculture, water supply, and flood control. Dams play a vital role in managing these resources, particularly for irrigation in Hawaii’s agriculture sector. Though Hawaii doesn’t have massive hydroelectric projects like many other regions, its dams are crucial for the islands’ sustainability and water management. This article explores the top 10 largest dams in Hawaii, detailing their location, river, capacity, and significance.
1. Lake Wilson (Wahiawa Dam)
- Location: Oahu
- River: Kaukonahua Stream
- Capacity: 3.5 billion gallons
Lake Wilson, also known as Wahiawa Dam, is the largest reservoir in Hawaii. Located on the island of Oahu, it plays a crucial role in irrigation, particularly for agriculture in central Oahu. The dam helps regulate the flow of Kaukonahua Stream and is an essential water source for the island’s farmers.
2. Nuuanu Reservoir No. 4
- Location: Oahu
- River: Nuuanu Stream
- Capacity: 1.2 billion gallons
Nuuanu Reservoir No. 4 is a key water supply reservoir located in the mountains above Honolulu. This dam was initially built for irrigation purposes and later became a critical source of drinking water for the city. The reservoir is also a popular spot for recreational fishing.
3. Ka Loko Reservoir
- Location: Kauai
- River: Waiakalua Stream
- Capacity: 1.4 billion gallons
Ka Loko Reservoir is one of the largest reservoirs on the island of Kauai. It was originally built to store water for sugarcane plantations and now serves agricultural irrigation purposes. The dam gained attention after a breach in 2006, leading to increased scrutiny on dam safety in Hawaii.
4. Waita Reservoir
- Location: Kauai
- River: Wahiawa Stream
- Capacity: 3 billion gallons
Waita Reservoir, located near the town of Koloa on Kauai, is one of the largest privately-owned reservoirs in Hawaii. It provides irrigation water to surrounding agricultural lands, particularly for farming and ranching operations.
5. Wailua Reservoir
- Location: Kauai
- River: North Fork Wailua River
- Capacity: 500 million gallons
Wailua Reservoir, situated in the central part of Kauai, is an important irrigation dam that helps sustain agriculture on the island. Its reservoir stores water from the North Fork of the Wailua River, ensuring a stable supply of water for crops.
6. Kualapuu Reservoir
- Location: Molokai
- River: None (Rain-fed)
- Capacity: 300 million gallons
Kualapuu Reservoir on Molokai is the largest reservoir on the island. It serves the agricultural needs of farmers by providing irrigation water, and it is fed primarily by rainfall rather than a river or stream. The dam supports local agriculture, particularly in the production of crops like coffee and macadamia nuts.
7. West Maui Reservoir (Kahoma Reservoir)
- Location: Maui
- River: Kahoma Stream
- Capacity: 1.2 billion gallons
West Maui Reservoir, also known as Kahoma Reservoir, is an important water source for agricultural activities in the region. The reservoir collects water from Kahoma Stream and is primarily used for irrigation of sugarcane fields and other crops in the area.
8. Alexander Reservoir
- Location: Kauai
- River: Hanalei River
- Capacity: 800 million gallons
Alexander Reservoir, located in northern Kauai, is a crucial dam for irrigation in the Hanalei Valley. The reservoir helps regulate the flow of the Hanalei River and provides water to taro fields, a traditional crop of great cultural and economic importance to the island.
9. Olokele Reservoir
- Location: Kauai
- River: Olokele Stream
- Capacity: 600 million gallons
Olokele Reservoir is located on the island of Kauai and serves the agricultural sector, particularly for sugarcane and other crops. The reservoir collects water from the Olokele Stream and helps manage water supply for irrigation during dry periods.
10. Blue Hole Reservoir
- Location: Kauai
- River: Wainiha River
- Capacity: 1 billion gallons
Blue Hole Reservoir, located on the island of Kauai, is known for its picturesque setting within the island’s interior. It collects water from the Wainiha River and provides vital irrigation for agricultural lands in the region, especially for taro farming.
Conclusion
The dams of Hawaii are essential to the islands’ agriculture, water supply, and flood control. From Lake Wilson on Oahu to the historic reservoirs of Kauai, these water storage facilities help manage Hawaii’s valuable water resources. Although the dams in Hawaii are not used primarily for hydroelectric power, they play a crucial role in sustaining agriculture, controlling floods, and supporting the state’s growing population. As water becomes an increasingly precious resource, the importance of these dams in Hawaii’s future development will continue to grow.
