Nuuanu Dam No. 4 dam
Nuuanu Dam No. 4
Nuuanu Dam No. 4, also known as Nuuanu Reservoir, is a vital structure located in Honolulu, Hawaii, along the Nuuanu Stream. Built in 1910, this earth dam stands at a height of 66 feet, with a hydraulic height of 69 feet and a structural height of 73 feet. It serves multiple purposes, including flood risk reduction, and has a storage capacity of 3,600 acre-feet. The dam is regulated by the DLNR and undergoes regular inspections to ensure its safety and functionality.
With a hazard potential rated as high and a condition assessment of fair, Nuuanu Dam No. 4 is considered to have a moderate risk level. The spillway of the dam is uncontrolled, with a width of 55 feet, and it has a maximum discharge capacity of 4,000 cubic feet per second. The dam covers a surface area of 25 acres and has a drainage area of 1.4 square miles. In case of emergencies, it is crucial for the authorities to have an effective Emergency Action Plan (EAP) in place to mitigate risks and protect the surrounding community.
Overall, Nuuanu Dam No. 4 plays a significant role in managing water resources and reducing flood risks in the region. As a local government-owned structure, it highlights the importance of proper regulation, inspection, and maintenance to ensure its continued effectiveness. For water resource and climate enthusiasts, this dam serves as a fascinating example of how engineering solutions can address environmental challenges and enhance community safety.
Dam data reference
Condition Assessment
- Satisfactory
- No 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.
- 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.
- 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.
Hazard Potential Classification
- High
- Dams 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, environmental 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.
Plan around the weather
Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind. Each cell is colour-coded relative to the column min/max.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day temperature & precipitation
Daily temperatures, snow, and rain projected over the next two weeks.
Nearby streamflow gauges
USGS streamgauges around Nuuanu Dam No. 4 -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Waihi Stream At Honolulu | 2 cfs | → |
| Waiakeakua Str At Honolulu | 4 cfs | → |
| Kalihi Str Nr Honolulu | 5 cfs | → |
| Makawao Str Nr Kailua | 7 cfs | → |
| Pukele Stream Near Honolulu | 1 cfs | → |
| Waiomao Stream Nr Honolulu | 0 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Nuuanu Dam No. 4.
Track Nuuanu Dam No. 4 in the Snoflo app
Save this dam as a favorite and get the local NOAA / yr.no forecast plus regional flow context wherever you are.
About Nuuanu Dam No. 4
Where does the data for Nuuanu Dam No. 4 come from?
Structural and regulatory data come from the U.S. Army Corps of Engineers' National Inventory of Dams (NID). Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.
How often is the report updated?
NID structural data refreshes annually as the Corps publishes updated assessments. The weather forecast refreshes throughout the day.
What does the High hazard rating mean?
The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card above for the full definitions.
What's "% of normal"?
The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).
Can I get alerts when storage crosses a threshold?
Yes -- alerts are managed in the Snoflo iOS app. Favorite this dam, set a threshold, and you'll get a push the moment conditions cross.
Other water bodies near here
Snoflo-tracked reservoirs and dams within driving distance of Nuuanu Dam No. 4.