Lake Eleanor
Lake Eleanor is an arch dam located in Ventura County, California, built in 1881. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Lake Eleanor
The primary purpose of Lake Eleanor 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 Conejo Open Space Conservation Agency (public utility). It impounds the Eleanor Creek near Thousand Oaks.
The dam stands 37 feet tall and stretches 140 feet across, creates a reservoir covering 9 acres, has a maximum storage capacity of 104 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1881, 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 03/19/2025.
At 37 feet, this dam is taller than 84% 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 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 | Eleanor Creek |
| Coordinates | 34.13550, -118.85170 |
Physical Characteristics
| Dam Type | Arch |
| NID Height | 37 ft |
| Dam Height | 37 ft |
| Dam Length | 140 ft |
| Year Completed | 1881 (145 years old) |
Storage & Hydraulics
| NID Storage | 104 acre-ft |
| Max Storage | 104 acre-ft |
| Surface Area | 9 acres |
| Drainage Area | 1 sq mi |
Ownership & Safety
| Purpose | Water Supply |
| Owner | Conejo Open Space Conservation Agency |
| Owner Type | Public Utility |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 03/19/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CA00737 |
| Federal ID | CA00737 |
| More Info | State Dam Safety Program |