PBS&J’s Minimum Flows and Levels: Florida’s Challenge

Minimum Flows and Levels: Florida’s Challenge

Minimum flows and levels (MFLs) are intended to guide water resource and water supply development to promote water resource sustainability for Florida citizens and the natural environment. They will also be used to assist in making water use and other permitting decisions and are being established to:

Address the requirements of Florida Statute 373.042(1)(a)&(b)
Protect water resources and ecology
Determine water availability

MFLs have not yet been established for many watercourses and lakes in the state or for any of Florida's groundwater aquifers. While MFLs can provide a baseline against which the cumulative effects of water withdrawals can be measured, the establishment of a minimum flow or level for any particular watercourse or water body can be an immensely complicated task involving the analysis and consideration of both technical and socioeconomic information.

MFL rules (e.g., 40D-8 and 40D-80, F.A.C.) have been refined over the past years and technical methods have been developed for use in establishing MFLs. Nonetheless, certain issues in the MFL process must be addressed on a case-specific basis for each particular watercourse or water body and the same methods do not apply to all river systems.

How PBS&J Helps
PBS&J scientists work with water management district staff to identify the best approach for each system. Approaches may include characterizing vegetation and soils and identifying commensurate water levels, developing criteria for certain species with particular life cycle requirements, targeting specific habitats and inundation requirements, and identifying potential impacts of altered flows. PBS&J scientists have considerable experience with MFL issues and methodologies and are currently providing technical assistance to several Florida Water Management Districts to develop MFLs for priority water bodies. In addition to technical support, PBS&J team members work to assist district staff in facilitating public input on issues and considerations relative to MFLs.

The statutory directive for MFLs was included in the Water Resources Act enacted by the Florida Legislature in 1972 and Section 373.042 F.S., which directs each water management district to establish MFLs for surface waters and aquifers within their respective jurisdictions. Under the statute, the minimum flow for a given watercourse is defined as the limit at which further withdrawals would be “significantly harmful” to the water resources or ecology of the area. In addition, the determination of MFLs must be based on the “best available” information as well as the protection of nonconsumptive uses of water (e.g., recreation).

Comprehensive Capabilities
PBS&J's staff capabilities can assist water management district staff with MFL-related issues, projects, and policy:

Extensive knowledge of the ecology of riverine and wetland systems.
Knowledge of regulatory requirements related to MFLs.
Experience with MFL issues and policy.
Technical expertise in biology, botany, ecology, hydrology, statistics, modeling, GIS, and consensus building, necessary to develop MFLs.
Experience in developing alternative approaches for different systems.