Lake Sherwood
Lake Sherwood is an arch dam located in Ventura County, California, built in 1904. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Lake Sherwood
The primary purpose of Lake Sherwood 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 Sherwood Valley Homeowners Association (private). It impounds the Potrero Valley Cr near Westlake.
The dam stands 45 feet tall and stretches 350 feet across, creates a reservoir covering 163 acres, and has a maximum storage capacity of 2,600 acre-feet. Completed in 1904, 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 03/20/2025.
At 45 feet, this dam is taller than 91% 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 | Westlake |
| River/Stream | Potrero Valley Cr |
| Coordinates | 34.13920, -118.85680 |
Physical Characteristics
| Dam Type | Arch |
| NID Height | 45 ft |
| Dam Height | 45 ft |
| Dam Length | 350 ft |
| Year Completed | 1904 (122 years old) |
Storage & Hydraulics
| NID Storage | 2,600 acre-ft |
| Max Storage | 2,600 acre-ft |
| Surface Area | 163 acres |
Ownership & Safety
| Purpose | Water Supply |
| Owner | Sherwood Valley Homeowners Association |
| Owner Type | Private |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 03/20/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CA00736 |
| Federal ID | CA00736 |
| More Info | State Dam Safety Program |