Waimanalo 60 Mg Reservoir Reservoir Report
Nearby: Nuuanu Dam No. 4 Kaneohe Dam
Last Updated: December 19, 2025
Waimanalo 60 Mg Reservoir, located in Honolulu, Hawaii, is a state-regulated water storage facility designed by USDA NRCS and completed in 1993.
°F
°F
mph
Wind
%
Humidity
Summary
With a primary purpose of irrigation, this earth dam stands at a height of 65 feet and has a hydraulic height of 62 feet. The reservoir has a maximum storage capacity of 182 acre-feet and covers a surface area of 5 acres, serving as a vital water resource for the surrounding agricultural lands.
Despite its fair condition assessment and high hazard potential, the reservoir has an uncontrolled spillway and outlet gates. The dam, fed by an irrigation ditch, has a moderate risk assessment rating and is inspected every 5 years to ensure its structural integrity. With a drainage area of 0.01 square miles and a maximum discharge of 200 cubic feet per second, Waimanalo 60 Mg Reservoir plays a crucial role in supporting the local community's water needs and contributing to sustainable agriculture practices in the region.
Managed by the DLNR and situated in the beautiful city of Waimanalo, this reservoir not only provides essential irrigation water but also serves as a key element in the region's water resource management efforts. With its strategic location and significant storage capacity, Waimanalo 60 Mg Reservoir stands as a testament to effective collaboration between state agencies and federal designers in ensuring water security and resilience in the face of climate challenges.
Year Completed |
1993 |
Dam Length |
2118 |
Dam Height |
65 |
River Or Stream |
FED BY IRRIGATION DITCH |
Primary Dam Type |
Earth |
Surface Area |
5 |
Hydraulic Height |
62 |
Drainage Area |
0.01 |
Nid Storage |
182 |
Structural Height |
65 |
Outlet Gates |
Uncontrolled |
Hazard Potential |
High |
Foundations |
Unlisted/Unknown |
Nid Height |
65 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
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
| Location | Reservations | Toilets |
|---|---|---|
Bellows Field Beach Park - Oahu
|
||
Waimanalo beach park
|
||
Kulamanu Beach
|
||
Sand Island State Rec Area - Oahu
|
||
Keaiwa Heiau State Rec Area - Oahu
|
Waimanalo 60 Mg Reservoir