Gilmore is an earth dam located in San Joaquin County, California, built in 1918. It carries a Significant hazard potential classification and has a satisfactory condition assessment.
Dam profile
NID height · 28 ft28 ft tall and 1,080 ft long, taller than 62% 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 Gilmore
The primary purpose of Gilmore 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 Susan Grupe Depolo and Luanne Grupe Rotticci (private). It impounds the Tr Mormon Slough.
The dam stands 28 feet tall and stretches 1,080 feet across, creates a reservoir covering 52 acres, has a maximum storage capacity of 550 acre-feet, and collects water from a drainage area of 4 square miles. Completed in 1918, the structure is over a century 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 04/07/2025.
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Location
| State | California |
| County | San Joaquin |
| River/Stream | Tr Mormon Slough |
| Coordinates | 38.04460, -120.99080 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 28 ft |
| Dam Height | 28 ft |
| Dam Length | 1,080 ft |
| Year Completed | 1918 (108 years old) |
Storage & Hydraulics
| NID Storage | 550 acre-ft |
| Max Storage | 550 acre-ft |
| Surface Area | 52 acres |
| Drainage Area | 4 sq mi |
Ownership & Safety
| Purpose | Water Supply |
| Owner | Susan Grupe Depolo and Luanne Grupe Rotticci |
| Owner Type | Private |
| Hazard Classification | Significant |
| Condition Assessment | Satisfactory |
| Last Inspection | 04/07/2025 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | CA00655 |
| Federal ID | CA00655 |
| More Info | State Dam Safety Program |