Florida Administrative Code
40 - WATER MANAGEMENT DISTRICTS
40E - South Florida Water Management District
Chapter 40E-8 - MINIMUM FLOWS AND LEVELS
Part II - MFL CRITERIA FOR LOWER EAST COAST REGIONAL PLANNING AREA
Section 40E-8.221 - Minimum Flows and Levels (MFLs): Surface Waters

(a) A MFL exceedance occurs during a 365-day period when the 30-day moving average flow at S-79 is below 457 cfs.

(b) A MFL violation occurs when a MFL exceedance occurs more than once in a 5-year period.

The flow, combined with tributary contributions below S-79, shall be sufficient to maintain a salinity gradient that prevents significant harm to mobile and immobile indicator species within the Caloosahatchee River. If significant harm occurs once the Caloosahatchee MFL recovery strategy is fully implemented and operational, the recovery strategy and MFL will be reviewed in accordance with Rule 40E-8.421, F.A.C. Mobile and immobile species shall be monitored as described in the recovery strategy.

(a) Criteria for Peat-Forming Wetlands. Water levels within wetlands overlying organic peat soils within the water conservation areas, Rotenberger and Holeyland wildlife management areas, and Shark River Slough (Everglades National Park) shall not fall 1.0 feet or more below ground surface, as measured at a key gage, for one or more days during a period in which the water level has remained below ground for a minimum of 30 days, at specific return frequencies as specified in Table 1, below.

(b) Criteria for Marl-Forming Wetlands. Water levels within marl-forming wetlands that are located east and west of Shark River Slough, the Rocky Glades, and Taylor Slough within Everglades National Park, shall not fall 1.5 feet below ground surface, as measured at a key gage, for one or more days during a period in which the water level has remained below ground for a minimum of 90 days, at specific return frequencies for different areas, as identified in Table 1, below.

The MFL criteria listed in Table 1 are based on existing changes and structural alterations to the pre-drainage conditions of the Everglades. It is the District's intent through implementation of the LEC Plan and the CERP to achieve minimum hydropattern return frequencies that approximate CERP compatible pre-drainage conditions in the Everglades. As a result, as the existing structural changes and alterations are corrected, the MFL criteria contained herein will be modified through a rule amendment consistent with the LEC Plan and the CERP.

(a) An enhanced freshwater regime is necessary to prevent significant harm to the water resources and ecology of the Northwest Fork of the Loxahatchee River, pursuant to Sections 373.042 and 373.0421, F.S. By establishing the MFL set forth in paragraphs (b) and (c), along with implementation of the associated recovery strategy, it is the interim goal of the District to provide sufficient freshwater flows to create at River Mile 9.2 the freshwater regime found at River Mile 10.2.

(b) A MFL violation occurs within the Northwest fork of the Loxahatchee River when an exceedance, as defined in paragraph (c), occurs more than once in a six year period.

(c) A MFL exceedance occurs within the Northwest Fork of the Loxahatchee River when:

(d) In addition to this MFL, which is intended to achieve partial enhancement of the Northwest Fork of the Loxahatchee River to prevent significant harm, restoration of the Loxahatchee River beyond the MFL will be addressed pursuant to subsection 40E-8.421(6), F.A.C., and other applicable provisions of state law. This MFL will be reviewed within two years of adoption and revised, if necessary, to ensure consistency with the restoration goal and plan identified pursuant to Rule 40E-8.421, F.A.C., or other applicable provisions of state law.

(a) The minimum flow is that necessary to maintain salinity as described in paragraph (b), below. A net discharge into northeastern Florida Bay of 105, 000 acre-feet of water over a 365-day period (a running total measured at West Highway Creek, at 25°14'33'' north and 80°26'50'' west; Trout Creek, at 25°12'53'' north and 80°32'01'' west; Mud Creek, at 25°12'09'' north and 80°35'01'' west; Taylor River, at 25°11'27'' north and 80°38'21'' west; and McCormick Creek, at 25°10'03'' north and 80°43'55'' west), is estimated to be necessary to maintain salinity as described in paragraph (b), below.

(b) An exceedance of the minimum flow criteria will be deemed to occur when the average salinity over 30 or more consecutive days exceeds 30 parts per thousand at the Taylor River salinity monitoring station, located at 25°13'29'' north and 80°39'10'' west. Multiple events of 30 or more day periods with salinity greater than 30 parts per thousand, occurring within a single calendar year, are considered as a single exceedance.

(c) A minimum flow violation occurs when an exceedance occurs during each of two consecutive years, more often than once in a ten-year period. By this definition, three consecutive years of exceedances constitute a violation.