Whitlow Ranch Dam - Saddle Dike 1 is an earth dam located in Pinal County, Arizona, built in 1959. It carries a High hazard potential classification.
Dam profile
NID height · 149 ft149 ft tall and 837 ft long, taller than 99% of U.S. dams with a recorded height. Height is drawn to scale against a ten-story building, about 100 ft; the profile is a generic embankment section and the water level is illustrative.
About Whitlow Ranch Dam - Saddle Dike 1
The primary purpose of Whitlow Ranch Dam - Saddle Dike 1 is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by USACE - Los Angeles District (federal). It impounds the Queen Creek near Queen Valley.
The dam stands 149 feet tall and stretches 837 feet across, creates a reservoir covering 1 acres, has a maximum storage capacity of 64,910 acre-feet, and collects water from a drainage area of 143 square miles. Completed in 1959, the structure is well into its service life at over 50 years old.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. An emergency action plan is in place for this dam. The most recent inspection on record was 05/23/2018. That was 8 years ago, which is on the longer end for a high-hazard structure.
At 149 feet, this dam is taller than 99% of all dams in the United States.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Arizona dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Arizona |
| County | Pinal |
| Nearest City | Queen Valley |
| River/Stream | Queen Creek |
| Coordinates | 33.28846, -111.26013 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 149 ft |
| Dam Height | 149 ft |
| Dam Length | 837 ft |
| Year Completed | 1959 (67 years old) |
Storage & Hydraulics
| NID Storage | 64,910 acre-ft |
| Max Storage | 64,910 acre-ft |
| Surface Area | 1 acres |
| Drainage Area | 143 sq mi |
| Max Discharge | 147,000 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | USACE - Los Angeles District |
| Owner Type | Federal |
| Hazard Classification | High |
| Condition Assessment | Not assessed |
| Last Inspection | 05/23/2018 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | AZ10004 |
| Federal ID | AZ10004S001 |
| More Info | State Dam Safety Program |