Mill Pond is an earth dam located in Mendocino County, California, built in 1885. It carries a Low hazard potential classification and has a fair condition assessment.
Dam profile
NID height · 33 ft33 ft tall and 200 ft long, taller than 76% 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 Mill Pond
The primary purpose of Mill Pond 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 Mendocino Railway (private). It impounds the Alder and Maple Creek.
The dam stands 33 feet tall and stretches 200 feet across, creates a reservoir covering 6 acres, has a maximum storage capacity of 72 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1885, the structure is over a century old.
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 fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. The most recent inspection on record was 06/18/2025.
At 33 feet, this dam is taller than 76% of dams nationwide.
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Location
| State | California |
| County | Mendocino |
| River/Stream | Alder and Maple Creek |
| Coordinates | 39.44140, -123.81230 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 33 ft |
| Dam Height | 33 ft |
| Dam Length | 200 ft |
| Year Completed | 1885 (141 years old) |
Storage & Hydraulics
| NID Storage | 72 acre-ft |
| Max Storage | 72 acre-ft |
| Surface Area | 6 acres |
| Drainage Area | 0 sq mi |
Ownership & Safety
| Purpose | Water Supply |
| Owner | Mendocino Railway |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Fair |
| Last Inspection | 06/18/2025 |
| Emergency Action Plan | No |
Identifiers
| NID ID | CA01139 |
| Federal ID | CA01139 |
| More Info | State Dam Safety Program |