Fourth of July is an earth dam located in Rio Arriba County, New Mexico, built in 1960. It carries a High hazard potential classification and has a unsatisfactory condition assessment.
Dam profile
NID height · 20 ft20 ft tall and 400 ft long. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic embankment section and the water level is illustrative.
About Fourth of July
The primary purpose of Fourth of July is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Bia (federal). It impounds the Los Alamos Creek near Brazos.
The dam stands 20 feet tall and stretches 400 feet across, creates a reservoir covering 2 acres, has a maximum storage capacity of 44 acre-feet, and collects water from a drainage area of 2 square miles. Completed in 1960, 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. Its condition is rated unsatisfactory, indicating serious safety deficiencies exist that require immediate attention or remedial action. An emergency action plan is in place for this dam. The most recent inspection on record was 04/09/2022.
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 New Mexico 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 | New Mexico |
| County | Rio Arriba |
| Nearest City | Brazos |
| River/Stream | Los Alamos Creek |
| Coordinates | 36.88240, -106.55260 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 20 ft |
| Dam Height | 20 ft |
| Dam Length | 400 ft |
| Year Completed | 1960 (66 years old) |
Storage & Hydraulics
| NID Storage | 44 acre-ft |
| Max Storage | 44 acre-ft |
| Normal Storage | 34 acre-ft |
| Surface Area | 2 acres |
| Drainage Area | 2 sq mi |
| Max Discharge | 288 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Irrigation |
| Owner | Bia |
| Owner Type | Federal |
| Hazard Classification | High |
| Condition Assessment | Unsatisfactory |
| Last Inspection | 04/09/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NM00681 |
| Federal ID | NM00681 |
| More Info | State Dam Safety Program |