Hil21

UNNAMED POND· Hillsborough, Florida· Earth· 51 ft tall
Unknown Tailings Private

Key Takeaway

Hil21 is classified as unknown in Florida. Its primary use is tailings.

Physical Details

Dam Height 51 ft (taller than 88.6% in FL)
Dam Length18,842 ft
Dam TypeEarth
Max Storage29.9K acre-ft
Normal Storage4.7K acre-ft
Surface Area497 acres
NID IDFL12019

Safety Information

Unknown

Hazard potential has not been determined.

Hazard potential describes downstream consequences of failure, not the dam's current condition. What does this mean?

Emergency Action Plan: No
State Regulated: Yes
Regulatory Agency: FDEP

Ownership

THE MOSAIC COMPANY

Private

Nearby Dams

Frequently Asked Questions

What is the hazard classification of Hil21?

Hil21 is classified as Unknown. Hazard potential has not been determined. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Hil21?

Hil21 is owned by THE MOSAIC COMPANY (Private). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

What is the primary purpose of Hil21?

Hil21 serves the following purposes: Tailings. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Hil21?

Hil21 has a dam height of 51 ft. Dam height is measured from the natural streambed at the downstream toe to the top of the dam, and may differ from the visible height.

Data from the National Inventory of Dams (NID) maintained by the US Army Corps of Engineers. Dam conditions may have changed since the last update. This site is not affiliated with USACE. Do not use for emergency planning — contact your local dam safety program.