Udall dam
Udall
Udall is a privately owned dam located in Apache County, Arizona, along the Little Colorado River. Built in 1910, this earth dam stands at a height of 24 feet and stretches 423 feet in length, with a storage capacity of 5,000 acre-feet. Its primary purpose is for debris control and irrigation, serving the local community of Hunt. Despite its age, Udall has a low hazard potential and is currently classified as "Not Rated" in terms of its condition assessment.
Managed by the Arizona Department of Water Resources, Udall is subject to state regulation, permitting, inspection, and enforcement. The dam has a drainage area of 2,300 square miles and a maximum discharge capacity of 500 cubic feet per second. While the dam's spillway is uncontrolled with a width of 39 feet, its risk assessment is deemed moderate. The last inspection of Udall took place in June 2006, with an assigned inspection frequency of 5 years.
For water resource and climate enthusiasts, Udall presents an interesting case study of a historic dam that continues to play a vital role in local water management. With its low hazard potential and moderate risk assessment, Udall serves as a reminder of the importance of ongoing monitoring and maintenance of aging infrastructure to ensure the safety and sustainability of our water resources.
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 Udall -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Little Colorado R Blw Zion Res Nr St. Johns | · | → |
| Little Colorado River Ab Zion Res Nr St. Johns | · | → |
| Carrizo Wash Nr St. Johns | 0 cfs | → |
| Little Colorado R Blw Salado Springs | · | → |
| Little Colorado R Abv Lyman Lake Nr St. Johns | 0 cfs | → |
| Little Colorado River At Woodruff | 0 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Udall.
Fishing spots
- Concho Lake
- Lyman Lake
- Bunch Reservoir
- River Reservoir South Fishing Site
- Fools Hollow Lake
- Nelson Reservoir
Paddle runs
- Eastern Boundary Of Park (Original Park Boundary) To Western Boundary Of Park (Original Park Boundary)
- South Fork Little Colorado River
- West Fork Little Colorado River
- State Highway 261 To 1/2 Mile Above Crosby Crossing
- Headwaters In Mount Baldy Wilderness To 0.1 Miles Above Upper Fish Barrier
- Headwaters In Mount Baldy Wilderness To Wilderness Boundary
Track Udall 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 Udall
Where does the data for Udall 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 Udall.