S-159 Upper
S-159 Upper is a concrete dam located in Hillsborough, Florida, built in 1980. It carries a High hazard potential classification and has a satisfactory condition assessment.
About S-159 Upper
The primary purpose of S-159 Upper is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by Swfwmd (local government). It impounds the Hillsborough River near Citrus Park.
The dam stands 38 feet tall and stretches 90 feet across, creates a reservoir covering 223 acres, has a maximum storage capacity of 6,000 acre-feet, and collects water from a drainage area of 33 square miles. Completed in 1980, the structure is 46 years old.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. 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 11/15/2024.
At 38 feet, this dam is taller than 85% of dams nationwide.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Florida dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Florida |
| County | Hillsborough |
| Nearest City | Citrus Park |
| River/Stream | Hillsborough River |
| Coordinates | 28.04133, -82.34517 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 38 ft |
| Dam Height | 38 ft |
| Dam Length | 90 ft |
| Year Completed | 1980 (46 years old) |
Storage & Hydraulics
| NID Storage | 6,000 acre-ft |
| Max Storage | 6,000 acre-ft |
| Normal Storage | 4,785 acre-ft |
| Surface Area | 223 acres |
| Drainage Area | 33 sq mi |
| Max Discharge | 7,200 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | SWFWMD |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 11/15/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | FL12001 |
| Federal ID | FL12001 |
| More Info | State Dam Safety Program |