Issue papers
- Cooperative Funding
- Comprehensive Watershed Management
- Exotic Species Management
- Flood Protection
- Funding Water Resources Protection
- Minimum Flows and Levels
- Mitigation
- Partnership Agreement
- Permitting
- Protecting Lands and Providing Public Uses
- Responsibilities
- Sinkholes
- Springs — A Unique Resource
- A Sustainable Water Supply
In Florida, water is a public resource belonging to everyone. The Southwest Florida Water Management District has the statutory responsibility to issue water use permits allowing permit holders to draw water from surface water bodies (rivers, lakes, streams) or from underground (the aquifer).
A permit is literally a permission slip to use the public’s water resource for a limited time, in a limited way, under specific conditions. To obtain a permit, the applicant must show that the use meets three statutory criteria: the use is reasonable and beneficial; is in the public interest; and does not interfere with existing legal users.
The District also has the responsibility to manage and protect natural systems. Striking a balance between these two responsibilities is important — and difficult.
To help determine the amount of water which is available for human use from a particular source, the District must determine the water body’s minimum flow or level (MFL). An MFL is the limit at which further water withdrawals will cause significant harm to the water resources of the area and the related natural environment. Lakes and aquifers have minimum levels. Minimum flows are set for rivers and streams. The District uses this information, as well as other information particular to a proposed withdrawal, when determining how much water an applicant may be allowed to withdraw from the water body.
When a river or stream drops below its minimum flow, the aquatic life (plants and animals) of that ecosystem can be harmed. The flow of rivers and streams also impacts estuaries, which are semi–closed water bodies where fresh water and salt water mix. Most fish and other aquatic animal life spend part of their development in an estuary environment. Without enough fresh water flowing in from rivers and streams, an estuary becomes saltier, disrupting the delicate balance of life.
Likewise, when a lake drops below its minimum level, the ecosystem that the lake is a part of can be disrupted. If water levels are not restored, the environment, the economy and the quality of life in the area are reduced.
In coastal areas, when water levels in the aquifer drop too low, salt water from the Gulf of Mexico can creep, or intrude, further into the freshwater aquifer, the source of 80 percent of the District’s drinking water. Once this happens, that part of the aquifer becomes mineralized and requires a special treatment process to purify it to drinking water or irrigation standards.
Inland, when water levels in the aquifer drop, surface water bodies — lakes and wetlands — may be affected and drop as well.
The District has an aggressive program to establish MFLs. The District has performed minimum flow studies on all major rivers in the District. Minimum flow regulations have been established as part of specific conditions on water use permits for the Little Manatee, Manatee and Lower Peace rivers. Minimum flows may also be adopted as regulatory rules that apply to all present and future users of a river. Minimum flows have been established by rule for the Lower Hillsborough River; minimum levels have been established by rule for priority lakes and wetlands in Northern Tampa Bay. The District also has a priority list and schedule for the adoption of additional MFLs for water bodies throughout the District. The schedule is updated on an annual basis. The District proposes to undertake voluntary scientific peer review for future MFLs. The peer review process allows an independent panel of experts to review the scientific methodologies and data used in establishing the levels. It is hoped that the peer review process will reduce potential litigation involving the MFLs.
The District also establishes guidance and minimum levels for lakes. The object of this program is to identify a series of levels representing a healthy fluctuation range for each lake. Guidance levels have been adopted on nearly 400 lakes (about 70 percent in the District). These levels are used in the operation of lake level structures and can be used by local governments in guiding growth and development adjacent to lakes.
Minimum flows and levels help the District advise permit holders “when to say when,” thus protecting the environment, the long–term or sustainable health of the water resource, and our special Florida way of life.
August 2001
