Thomas Briles
Thomas Briles is an earth dam located in Modoc County, California, built in 1910. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Thomas Briles
The primary purpose of Thomas Briles is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is owned by Modoc Ranch Properties, Llc. (private). It impounds the Tr Goose Lake.
The dam stands 23 feet tall and stretches 345 feet across, creates a reservoir covering 20 acres, has a maximum storage capacity of 209 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1910, 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 satisfactory, indicating no existing or potential dam safety deficiencies are recognized. Notably, no emergency action plan is currently on file for this high-hazard dam. The most recent inspection on record was 04/23/2025.
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 California 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 | California |
| County | Modoc |
| River/Stream | Tr Goose Lake |
| Coordinates | 41.76880, -120.35270 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 23 ft |
| Dam Height | 23 ft |
| Dam Length | 345 ft |
| Year Completed | 1910 (116 years old) |
Storage & Hydraulics
| NID Storage | 209 acre-ft |
| Max Storage | 209 acre-ft |
| Surface Area | 20 acres |
| Drainage Area | 1 sq mi |
Ownership & Safety
| Purpose | Water Supply |
| Owner | Modoc Ranch Properties, LLC. |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 04/23/2025 |
| Emergency Action Plan | No |
Identifiers
| NID ID | CA00490 |
| Federal ID | CA00490 |
| More Info | State Dam Safety Program |