Alexander Reservoir Report
Nearby: Elima Reservoir Elua Reservoir
Last Updated: December 19, 2025
Alexander Reservoir, located in Wahiawa Camp 2, Kauai, Hawaii, is a privately owned earth dam built in 1931 primarily for irrigation purposes.
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Summary
With a dam height of 112 feet and a hydraulic height of 119 feet, the reservoir has a storage capacity of 2540 acre-feet and serves the local agricultural community. It is regulated by the Hawaii Department of Land and Natural Resources (DLNR) and undergoes regular inspections to ensure its safety and functionality.
The reservoir, situated on the Wahiawa Stream, covers a surface area of 31.5 acres and has a moderate hazard potential. Despite being classified as fair in terms of condition assessment, Alexander remains a crucial water resource for the region, supporting both hydroelectric and irrigation needs. The dam's uncontrolled spillway, with a width of 393 feet, allows for the safe release of excess water during periods of high discharge, minimizing the risk of flooding and ensuring the stability of the structure.
Owned and operated by a private entity, Alexander Reservoir plays a vital role in sustaining the agricultural landscape of Kauai. With its strategic location and efficient design, the reservoir continues to contribute to the local economy while adhering to state regulations and enforcement measures. As climate change impacts water resources, the maintenance and management of such vital infrastructure are essential for ensuring water security and resilience in the face of evolving environmental challenges.
Year Completed |
1931 |
Dam Length |
600 |
Dam Height |
112 |
River Or Stream |
WAHIAWA STREAM |
Primary Dam Type |
Earth |
Surface Area |
31.5 |
Hydraulic Height |
119 |
Drainage Area |
2.86 |
Nid Storage |
2540 |
Structural Height |
119 |
Hazard Potential |
High |
Foundations |
Unlisted/Unknown |
Nid Height |
119 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Waimea River Nr Waimea
|
295cfs |
Waialae Str At Alt 3
|
34cfs |
Eb Of Nf Wailua River Nr Lihue
|
39cfs |
Sf Wailua River Nr Lihue
|
173cfs |
Left Branch Opaekaa Str Nr Kapaa
|
2cfs |
Wainiha River Nr Hanalei
|
178cfs |
Dam Data Reference
Condition Assessment
SatisfactoryNo existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
Fair
No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
Poor A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency. Investigations and studies are necessary.
Unsatisfactory
A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
Not Rated
The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Not Available
Dams for which the condition assessment is restricted to approved government users.
Hazard Potential Classification
HighDams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
Low
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
Undetermined
Dams for which a downstream hazard potential has not been designated or is not provided.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.
Area Campgrounds
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Lucy Wright Beach Park - Kauai
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Kaluahaulu
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Alexander