Richardson
Richardson is an earth dam located in Sonoma County, California, built in 1954. It carries a Significant hazard potential classification and has a satisfactory condition assessment.
About Richardson
The primary purpose of Richardson 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 Soper-wheeler Company (private). It impounds the Unnamed Tributary To Pepperwood Creek.
The dam stands 65 feet tall and stretches 265 feet across, creates a reservoir covering 22 acres, has a maximum storage capacity of 520 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1954, the structure is well into its service life at over 50 years old.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. 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 05/15/2025.
At 65 feet, this dam is taller than 96% of all dams in the United States.
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Location
| State | California |
| County | Sonoma |
| River/Stream | Unnamed Tributary To Pepperwood Creek |
| Coordinates | 38.62620, -123.18690 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 65 ft |
| Dam Height | 65 ft |
| Dam Length | 265 ft |
| Year Completed | 1954 (72 years old) |
Storage & Hydraulics
| NID Storage | 520 acre-ft |
| Max Storage | 520 acre-ft |
| Surface Area | 22 acres |
| Drainage Area | 0 sq mi |
Ownership & Safety
| Purpose | Water Supply |
| Owner | Soper-Wheeler Company |
| Owner Type | Private |
| Hazard Classification | Significant |
| Condition Assessment | Satisfactory |
| Last Inspection | 05/15/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CA00994 |
| Federal ID | CA00994 |
| More Info | State Dam Safety Program |