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Minimum Flows and Minimum Water Levels and Reservations

One major challenge associated with water supply planning is finding the balance between meeting public water supply needs while maintaining the healthy natural systems essential to Florida's economy and quality of life. Two ways that water managers ensure that the water resources and associated ecological systems are protected are through the implementation of Minimum Flows and Minimum Water Levels (MFLs) and Water Use Reservations (Reservations) programs. 

MFLs and Reservations are adopted in accordance with the district's MFL and Reservation Priority List and Schedule, submitted annually to the department for approval. The latest Priority Lists, as well as other information about district MFLs, are available on the districts' websites:

Image of Silver Glen Spring Minimum Flows and Minimum Water Levels (MFLs)

Florida's fresh water sources, including rivers, streams, lakes, springs, wetlands and aquifers, have intrinsic economic, ecological and aesthetic value. Each water body needs a certain amount of water to properly function and retain its value. For example, Florida's springs are important warm water refuges for the endangered West Indian manatee during the winter. The rivers connecting the springs to the sea must maintain certain depths and widths in order for manatees to be able to pass through during colder months. 

Scientists study each unique water system, assess the water resource values associated with the system (such as kayaking, fishing or manatee passage), and identify the minimum flow or level that must be maintained to protect those resource values.  

It is possible for consumptive use to lower the flows and levels of water bodies to a point that the resource values are significantly harmed. To prevent this harm, the districts are responsible for identifying and establishing the limit at which further withdrawals would be significantly harmful to the water resources or ecology of the area. 

This limit is the minimum flow or minimum level. MFLs must be established consistent with section 373.042, F.S., and Rule 62-40.473, F.A.C. 

A map of all of the adopted MFLs in the state is available here.

Recovery and Prevention StrategiesBlue Spring State Park - Manatees in clear water

For water bodies that are below their minimum flow or level, or are projected to fall below it within 20 years, the districts are required to implement a recovery or prevention strategy to ensure the MFL is maintained over the long-term. 

Outstanding Florida Springs

In 2016, the state Legislature directed the districts or department to establish an MFL for all Outstanding Florida Springs by July 1, 2017, or, for Northwest Florida Water Management District, by July 1, 2026. Outstanding Florida Springs include all historic first-magnitude springs and some second-magnitude springs of regional importance. 

There are 30 Outstanding Florida Springs in the state of Florida. 

Water Use ReservationsAn offshore view of the shoreline of Biscayne Bay Aquatic Preserve (Reservations)

Like MFLs, Reservations can be an effective tool for water resource management. 

A district or the department may, by rule, reserve water from use by permit applicants in such locations and quantities, and for such seasons of the year, as in its judgment may be required for the protection of fish and wildlife or public health and safety.

Such reservations shall be subject to periodic review at least every five years, and revised if necessary in light of changed conditions. However, all presently existing legal uses of water shall be protected so long as such use is not contrary to the public interest.

Reservations must be established consistent with section 373.223(4), F.S., and rule 62-40.474, F.A.C. 

Last Modified:
September 23, 2023 - 10:28am

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