Lang Creek Detention Basin
Lang Creek Detention Basin is an earth dam located in Ventura County, California, built in 2004. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Lang Creek Detention Basin
The primary purpose of Lang Creek Detention Basin 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 Ventura County Watershed Protection District (local government). It impounds the Lang Creek near Thousand Oaks.
The dam stands 67 feet tall and stretches 345 feet across, creates a reservoir covering 12 acres, and has a maximum storage capacity of 263 acre-feet. Completed in 2004, the structure is relatively new.
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 11/13/2025.
At 67 feet, this dam is taller than 96% 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 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 | Ventura |
| Nearest City | Thousand Oaks |
| River/Stream | Lang Creek |
| Coordinates | 34.21160, -118.82770 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 67 ft |
| Dam Height | 67 ft |
| Dam Length | 345 ft |
| Year Completed | 2004 (22 years old) |
Storage & Hydraulics
| NID Storage | 263 acre-ft |
| Max Storage | 263 acre-ft |
| Surface Area | 12 acres |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | Ventura County Watershed Protection District |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 11/13/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CA01368 |
| Federal ID | CA01368 |
| More Info | State Dam Safety Program |