Mosaic Csa F4b Reservoir Report
Nearby: Mosaic Csa F5 Mosaic Csa F4a
Last Updated: December 5, 2025
Mosaic Csa F4b is a privately owned earth dam located in Hillsborough, Florida, specifically in the city of Fort Lonesome.
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Summary
Completed in 2004, this dam serves as a tailings storage facility for the surrounding area. With a height of 60 feet and a length of 12,000 feet, Mosaic Csa F4b has a maximum storage capacity of 26,500 acre-feet and a normal storage capacity of 25,575 acre-feet.
The dam is situated on the Long Branch river and is regulated by the Florida Department of Environmental Protection. It has a controlled spillway with a width of 128 feet and a maximum discharge capacity of 640 cubic feet per second. The hazard potential of Mosaic Csa F4b is considered significant, with a very high risk assessment rating of 1. Despite not having a condition assessment rating, the dam is inspected, permitted, and enforced by state regulatory agencies.
Overall, Mosaic Csa F4b plays a crucial role in managing water resources in the area and mitigating potential risks associated with its operation. Its design by Ardurman & Associates reflects a commitment to environmental stewardship and compliance with state regulations. For water resource and climate enthusiasts, Mosaic Csa F4b represents a fascinating intersection of engineering, environmental protection, and sustainable water management practices in Florida.
Year Completed |
2004 |
Dam Length |
12000 |
Dam Height |
60 |
River Or Stream |
LONG BRANCH |
Primary Dam Type |
Earth |
Surface Area |
465 |
Hydraulic Height |
55 |
Drainage Area |
0.73 |
Nid Storage |
26500 |
Structural Height |
62 |
Hazard Potential |
Significant |
Nid Height |
62 |
Seasonal Comparison
Weather Forecast
Nearby Streamflow Levels
Dam Data Reference
Condition Assessment
SatisfactoryNo existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
Fair
No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
Poor A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency. Investigations and studies are necessary.
Unsatisfactory
A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
Not Rated
The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Not Available
Dams for which the condition assessment is restricted to approved government users.
Hazard Potential Classification
HighDams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
Low
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
Undetermined
Dams for which a downstream hazard potential has not been designated or is not provided.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.
Mosaic Csa F4b