Bean Holl #3 is an earth dam located in San Mateo County, California, built in 1939. It carries a Low hazard potential classification and has a poor condition assessment.
Dam profile
NID height · 40 ft40 ft tall and 405 ft long, taller than 86% of U.S. dams with a recorded height. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic embankment section and the water level is illustrative.
About Bean Holl #3
The primary purpose of Bean Holl #3 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 Lake Lucerne Mutual Water Company (private). It impounds the Ar De Los Frijoles.
The dam stands 40 feet tall and stretches 405 feet across, creates a reservoir covering 36 acres, has a maximum storage capacity of 461 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1939, the structure is well-established, with more than 75 years of service.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life. Its condition is rated poor, meaning the dam has recognized safety deficiencies that require remediation to address risks. The most recent inspection on record was 03/24/2025.
At 40 feet, this dam is taller than 86% of dams nationwide.
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Location
| State | California |
| County | San Mateo |
| River/Stream | Ar De Los Frijoles |
| Coordinates | 37.20470, -122.36730 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 40 ft |
| Dam Height | 40 ft |
| Dam Length | 405 ft |
| Year Completed | 1939 (87 years old) |
Storage & Hydraulics
| NID Storage | 461 acre-ft |
| Max Storage | 461 acre-ft |
| Surface Area | 36 acres |
| Drainage Area | 1 sq mi |
Ownership & Safety
| Purpose | Water Supply |
| Owner | Lake Lucerne Mutual Water Company |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Poor |
| Last Inspection | 03/24/2025 |
| Emergency Action Plan | No |
Identifiers
| NID ID | CA00666 |
| Federal ID | CA00666 |
| More Info | State Dam Safety Program |