SFRC-93/03 Water Management in Taylor Slough and Effects on Florida Bay

Van Lent, Thomas; Johnson, Robert; Fennema, Robert

Current water management practices in the L-31N, L-31 W, and C-ll1 canals have contributed to lower groundwater levels and reduced surface water flows in the Rocky Glades and the Taylor Slough marshes. The reduced hydraulic gradients and the truncated periods of flow through the Taylor Slough basin are thought to be a major factor contributing to the hypersaline conditions and abrupt salinity changes in Florida Bay. The progressive lowering of L-31N canal stages from 5.5 to 4.3 feet in response to pressure from expanding urban and agricultural development has increased drainage from the marshes in Everglades National Park into the bordering canal system. If one looks at the entire reach of L-31N from the S-335 to S-176, well over 270,000 acre-ft per year are drained from the western marshes into L-31N. Approximately 50,000 acre-ft are returned to Taylor Slough, while 180,000 acre-ft are dumped into the lower C-1l1 basin. If we focus on the Rocky Glades, the historical headwaters of Taylor Slough, only about 60% of the water drained from this area is returned as deliveries to Taylor Slough via S-174. Thus, the source of water for S-174 water deliveries to Taylor Slough is primarily from drainage of the local Taylor Slough headwaters, not from the regional water supply system. Prior to 1981 L-31W canal stages were routinely allowed to reach 5.0 feet. With the increasing agricultural activities in the Frog Pond, L-31 W has been held at or below 4.5 feet, and L-31 W is used frequently to drain water from the Frog Pond and consequently, Taylor Slough. In a typical year, L-31W drains 41,000 acre-ft from Taylor Slough, while S-332 pumps 33,000 acre-ft back into Taylor Slough.

SFRC-93/03 Water Management in Taylor Slough and Effects on Florida Bay

Collections