Colter
Colter is an earth dam located in Apache County, Arizona, built in 1908. It carries a High hazard potential classification and has a poor condition assessment.
About Colter
The primary purpose of Colter is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Grovers Hill Irrigation District (private). It impounds the Little Colorado River near Greer.
The dam stands 19 feet tall and stretches 400 feet across, creates a reservoir covering 100 acres, has a maximum storage capacity of 732 acre-feet, and collects water from a drainage area of 5 square miles. Completed in 1908, the structure is over a century 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. Its condition is rated poor, meaning the dam has recognized safety deficiencies that require remediation to address risks. Notably, no emergency action plan is currently on file for this high-hazard dam. The most recent inspection on record was 09/05/2024.
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 | Apache |
| Nearest City | Greer |
| River/Stream | Little Colorado River |
| Coordinates | 33.94571, -109.47985 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 19 ft |
| Dam Height | 19 ft |
| Dam Length | 400 ft |
| Year Completed | 1908 (118 years old) |
Storage & Hydraulics
| NID Storage | 732 acre-ft |
| Max Storage | 732 acre-ft |
| Surface Area | 100 acres |
| Drainage Area | 5 sq mi |
| Max Discharge | 3,300 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | GROVERS HILL IRRIGATION DISTRICT |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Poor |
| Last Inspection | 09/05/2024 |
| Emergency Action Plan | No |
Identifiers
| NID ID | AZ00009 |
| Federal ID | AZ00009 |
| More Info | State Dam Safety Program |