Millett Swale dam
Millett Swale
Millett Swale, located in Navajo County, Arizona, is a vital flood risk reduction structure with a primary purpose of debris control and flood risk reduction. Constructed in 1958 by the USDA NRCS, this earth dam stands at a height of 24 feet and stretches 2500 feet in length, providing a storage capacity of 2104 acre-feet. Despite its crucial role in managing water resources, Millett Swale is facing challenges with a poor condition assessment and a high hazard potential, emphasizing the need for immediate attention and maintenance.
Managed by the Arizona Department of Water Resources, Millett Swale is regulated, permitted, inspected, and enforced in accordance with state regulations. With a drainage area of 40 square miles and a maximum discharge capacity of 6120 cubic feet per second, this structure plays a significant role in protecting the surrounding communities of Taylor and Shumway from potential flooding events. However, the dam's deteriorating condition raises concerns about its long-term effectiveness in safeguarding the area against flood risks, highlighting the importance of ongoing risk management measures and maintenance efforts.
Despite its critical importance in flood risk reduction, Millett Swale's current state of disrepair and high hazard potential underscore the urgent need for comprehensive risk assessment, maintenance, and potential rehabilitation efforts. As a key infrastructure managed by the Natural Resources Conservation Service, Millett Swale serves as a crucial component in the region's water resource management system, emphasizing the importance of proactive measures to ensure its continued functionality and resilience in the face of changing climate conditions and increasing water-related challenges.
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 Millett Swale -- inflows here typically show up in storage 24-72 hours later.
| Streamgauge | Discharge | View |
|---|---|---|
| Show Low Creek Near Lakeside | · | → |
| Little Colorado River At Woodruff | · | → |
| Little Colorado River At Holbrook | 51 cfs | → |
| Little Colorado R Blw Zion Res Nr St. Johns | · | → |
| Carrizo Creek Near Show Low | 1 cfs | → |
| Little Colorado River Near Joseph City | 2,700 cfs | → |
Make a day of it
Boat launches, lakeside camping, fishing access, and other reservoirs near Millett Swale.
Campgrounds
- Fool Hollow Lake Recreation Area Campground
- Fool Hollow State Rec Area
- Lewis Canyon Group Campground
- Show Low Lake
- Scott Reservoir Campground
- Scott Reservoir
Fishing spots
Paddle runs
- Eastern Boundary Of Park (Original Park Boundary) To Western Boundary Of Park (Original Park Boundary)
- 1/4 Mile Below Forest Road 504 Crossing To Forest Boundary In Section 1, T14n, R15e, Gila And Salt River Meridian
- West Fork Little Colorado River
- 0.1 Miles Above Diversion At Durfee Crossing To 1/4 Mile Below Forest Road 504 Crossing
- 1/4 Mile Below Chevelon Lake Dam To 0.1 Miles Above Diversion At Durfee Crossing
- Canyon Creek Springs To Fort Apache Indian Reservation Boundary
More reservoirs
Track Millett Swale 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 Millett Swale
Where does the data for Millett Swale 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 Millett Swale.