Peahi Reservoir dam
Peahi Reservoir
Peahi Reservoir, located in Ulumalu, Maui, Hawaii, is a privately owned irrigation structure completed in 1924 with a primary purpose of irrigation. The reservoir, with a height of 45 feet and a capacity of 72 acre-feet, serves as a critical water resource for the surrounding area, storing up to 66 acre-feet of water under normal conditions. The dam, of earth type with a buttress core, spans 170 feet in length and covers a surface area of 5.8 acres, drawing water from the Uaoa Stream for agricultural use.
Despite its essential role in supporting local agriculture, Peahi Reservoir poses a high hazard potential with a poor condition assessment, indicating the need for immediate attention and maintenance. The dam's spillway, of uncontrolled type, features a width of 32 feet to manage excess water flow during heavy rainfall events. While the structure has been inspected periodically, the last assessment in December 2018 revealed significant issues, prompting a risk assessment rating of moderate (3) and highlighting the importance of implementing effective risk management measures to ensure the safety and stability of the reservoir.
As climate change continues to impact water resources and infrastructure, Peahi Reservoir stands as a vital yet vulnerable asset in need of ongoing monitoring and maintenance. With its strategic location in the Honolulu District and close proximity to the Uaoa Stream, the reservoir plays a crucial role in sustaining local agriculture and community livelihoods, underscoring the importance of proactive management and investment in safeguarding water resources for future generations.
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 Peahi Reservoir -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Honopou Stream Near Huelo | 5 cfs | → |
| Opana Tunnel Near Kailiili | 2 cfs | → |
| Waikamoi Str Ab Res At Kula Pl Intake Nr Olinda | 1 cfs | → |
| West Wailuaiki Stream Near Keanae | 47 cfs | → |
| Hanawi Stream Near Nahiku | 16 cfs | → |
| Iao Stream At Kepaniwai Park Nr Wailuku | 87 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Peahi Reservoir.
Campgrounds
- Kanaha Beach Park - Maui
- Hosmer Grove
- Hosmer Grove - Haleakala National Park - Maui
- Holua Dispersed - Haleakala National Park - Maui
- Hōlua Campground
- Hōlua Campsites
Track Peahi Reservoir 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 Peahi Reservoir
Where does the data for Peahi Reservoir 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 Peahi Reservoir.