Twin Lakes South
Twin Lakes South is a dam located in Franklin County, Idaho, built in 1920. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Twin Lakes South
The primary purpose of Twin Lakes South is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is private-owned. It impounds the Deep Creek Bear River near Bear River Confluence.
The dam stands 36 feet tall and stretches 930 feet across, creates a reservoir covering 493 acres, has a storage capacity of 14,000 acre-feet, and collects water from a drainage area of 2 square miles. Completed in 1920, 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. An emergency action plan is in place for this dam. The most recent inspection on record was 11/19/2020.
At 36 feet, this dam is taller than 83% of dams nationwide.
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 Idaho 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 | Idaho |
| County | Franklin |
| Nearest City | Bear River Confluence |
| River/Stream | Deep Creek Bear River |
| Coordinates | 42.18570, -111.97420 |
Physical Characteristics
| NID Height | 36 ft |
| Dam Height | 36 ft |
| Dam Length | 930 ft |
| Year Completed | 1920 (106 years old) |
Storage & Hydraulics
| NID Storage | 14,000 acre-ft |
| Normal Storage | 14,000 acre-ft |
| Surface Area | 493 acres |
| Drainage Area | 2 sq mi |
| Spillway Type | None |
Ownership & Safety
| Purpose | Irrigation |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 11/19/2020 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | ID00077 |
| Federal ID | ID00077 |
| More Info | State Dam Safety Program |