Oso Largo Dam dam
Oso Largo Dam
Oso Largo Dam, located in Fort Thomas, Arizona, along the Gila River, was completed in 1971 by the Bureau of Land Management with a primary purpose of flood risk reduction. This gravity dam stands at a structural height of 26 feet with a hydraulic height of 21 feet, offering a storage capacity of 616.7 acre-feet and serving a drainage area of 93.7 square miles. With a surface area of 241 acres, this dam plays a critical role in managing water resources in the region.
Despite its low hazard potential, Oso Largo Dam has been assessed as unsatisfactory in condition, warranting a closer inspection and potential maintenance to ensure its long-term functionality. The dam features an uncontrolled spillway with a width of 5 feet and has a moderate risk level assigned to it. While the dam has not been modified in recent years, regular inspections are carried out every five years to monitor its structural integrity and safety measures. With Oso Largo Dam being a key component for flood risk reduction in the area, its management and maintenance are essential for water resource and climate enthusiasts to monitor.
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 Oso Largo Dam -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Frye Creek Near Thatcher | 1 cfs | → |
| Bonita Creek Near Morenci | 2 cfs | → |
| Gila River At Head Of Safford Valley | 22 cfs | → |
| Gila River At Calva | 13 cfs | → |
| Eagle Creek Above Pumping Plant | 35 cfs | → |
| Gila River Near Clifton | 15 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Oso Largo Dam.
Boat launches
Campgrounds
- Clark Peak Corrals
- Columbine Corrals Campground
- Columbine Corrals
- Riggs Flat
- Riggs Flat Campground
- Soldier Creek Campground
Track Oso Largo Dam 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 Oso Largo Dam
Where does the data for Oso Largo Dam 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 Low 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 Oso Largo Dam.