Big Four Mine Bf-1 is an earth dam located in Hillsborough, Florida, built in 1977. It carries a Low hazard potential classification.
Dam profile
NID height · 40 ft40 ft tall and 21,120 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 Big Four Mine Bf-1
The primary purpose of Big Four Mine Bf-1 is tailings. Tailings dams contain waste material from mining operations — typically a slurry of finely ground rock left over after valuable minerals have been extracted. These structures require ongoing monitoring because tailings can contain heavy metals and other contaminants. The dam is owned by The Mosaic Company (private). It impounds the Lake Branch Alafia River near Fish Hawk.
The dam stands 40 feet tall and stretches 21,120 feet across, creates a reservoir covering 450 acres, and has a maximum storage capacity of 18,000 acre-feet. Completed in 1977, the structure is 49 years 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.
At 40 feet, this dam is taller than 86% of dams nationwide.
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Location
| State | Florida |
| County | Hillsborough |
| Nearest City | Fish Hawk |
| River/Stream | Lake Branch Alafia River |
| Coordinates | 27.75000, -82.08000 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 40 ft |
| Dam Height | 40 ft |
| Dam Length | 21,120 ft |
| Year Completed | 1977 (49 years old) |
Storage & Hydraulics
| NID Storage | 18,000 acre-ft |
| Max Storage | 18,000 acre-ft |
| Normal Storage | 15,700 acre-ft |
| Surface Area | 450 acres |
Ownership & Safety
| Purpose | Tailings |
| Owner | The Mosaic Company |
| Owner Type | Private |
| Hazard Classification | Low |
| Condition Assessment | Not assessed |
| Emergency Action Plan | No |
Identifiers
| NID ID | FL00613 |
| Federal ID | FL00613 |
| More Info | State Dam Safety Program |