Structure 551

C-531 (LAKE TARPON CANAL)· Pinellas, Florida· Built 1970· Concrete· 8 ft tall

Low Hazard Flood Risk Reduction State Government

Key Takeaway

Structure 551 is classified as low hazard in Florida. It was completed in 1970 and is 56 years old. Its primary use is flood risk reduction.

Physical Details

Dam Height	8 ft (taller than 6.8% in FL)
Dam Length	250 ft
Dam Type	Concrete
Max Storage	24.4K acre-ft
Normal Storage	15.5K acre-ft

Surface Area	2,534 acres
Drainage Area	60 sq mi
Max Discharge	6,000 cfs
Year Completed	1970 (56 years old)
NID ID	FL00168

Safety Information

Low Hazard

No probable loss of human life and low economic/environmental losses expected.

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

Emergency Action Plan: Yes

Last Inspection: May 11, 2024

State Regulated: Yes

Regulatory Agency: FDEP

Ownership

SWFWMD

State Government

Nearby Dams

Swfwmd Lake Tarpon Control Structure (S-551)

Pinellas, FL

Low Hazard 16 ft

Keystone Lake Water Conservation Structure

Hillsborough, FL

Significant Hazard 6 ft

Lake Pretty Water Conservation Structure

Hillsborough, FL

Significant Hazard 5 ft

Frequently Asked Questions

What is the hazard classification of Structure 551?

Structure 551 is classified as Low Hazard. No probable loss of human life and low economic/environmental losses expected. This classification refers to the potential downstream consequences of a failure, not the dam's current structural condition.

Who owns and operates Structure 551?

Structure 551 is owned by SWFWMD (State Government). The owner is responsible for maintenance, inspections, and compliance with dam safety regulations.

When was Structure 551 built?

Structure 551 was completed in 1970, making it 56 years old. Many U.S. dams were built between the 1930s and 1970s during a period of major infrastructure investment.

What is the primary purpose of Structure 551?

Structure 551 serves the following purposes: Flood Risk Reduction. Many dams in the U.S. are multi-purpose, supporting flood control, water supply, recreation, and other uses.

How tall is Structure 551?

Structure 551 has a dam height of 8 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.

When was Structure 551 last inspected?

Structure 551 was last inspected on May 11, 2024. Inspection dates indicate when a formal review occurred, not the results of that inspection.

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.