Kingsford A-11

Kingsford A-11 is an earth dam located in Polk County, Florida, built in 1977. It carries a Significant hazard potential classification.

About Kingsford A-11

The primary purpose of Kingsford A-11 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 Alafia River near Keysville.

The dam stands 30 feet tall and stretches 12,800 feet across, creates a reservoir covering 277 acres, and has a maximum storage capacity of 8,300 acre-feet. Completed in 1977, the structure is 49 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.

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Significant HazardNot Rated ConditionEmergency Action Plan: No

Location

StateFlorida
CountyPolk
Nearest CityKeysville
River/StreamAlafia River
Coordinates27.84000, -82.02000

Physical Characteristics

Dam TypeEarth
NID Height30 ft
Dam Height30 ft
Dam Length12,800 ft
Year Completed1977 (49 years old)

Storage & Hydraulics

NID Storage8,300 acre-ft
Max Storage8,300 acre-ft
Normal Storage5,000 acre-ft
Surface Area277 acres
Max Discharge290 cfs

Ownership & Safety

PurposeTailings
OwnerTHE MOSAIC COMPANY
Owner TypePrivate
Hazard ClassificationSignificant
Condition AssessmentNot Rated
Emergency Action PlanNo

Identifiers

NID IDFL00664
Federal IDFL00664
More InfoState Dam Safety Program

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