Florida Watersheds Overview

Florida's water management districts describe its watersheds district by district: seven riverine-estuarine watersheds in the Panhandle, 13 Suwannee river basins, three St. Johns basins, the Green Swamp rivers and the Greater Everglades (NWFWMD; SRWMD).

In northwest Florida, the Northwest Florida Water Management District (NWFWMD) lists seven major riverine-estuarine watersheds: Apalachicola River and Bay, Choctawhatchee River and Bay, Ochlockonee River and Bay, the Pensacola Bay system, Perdido River and Bay, St. Andrew Bay, and St. Marks River and Apalachee Bay (NWFWMD SWIM).

In north-central Florida, the Suwannee River Water Management District (SRWMD) covers 7,640 square miles and 13 river basins. Its major rivers are the Alapaha, Aucilla, Econfina, Fenholloway, Ichetucknee, Santa Fe, Steinhatchee, Suwannee, Waccasassa, Wacissa and Withlacoochee (SRWMD).

On the Atlantic side, the St. Johns River Water Management District (SJRWMD) divides the St. Johns River into three watersheds, also known as drainage basins: the upper, middle and lower St. Johns (SJRWMD). In central and south Florida, the Green Swamp feeds four rivers, and Lake Okeechobee sits inside the Greater Everglades watershed (SWFWMD; SFWMD). No single statewide count of watersheds appears on these agency pages, so this guide uses each district's own grouping.

Four central Florida rivers, the Hillsborough, Withlacoochee, Peace and Ocklawaha, all begin in the Green Swamp, and together they provide much of central Florida's water supply (SWFWMD, Four Rivers Emerge).

The Green Swamp rivers leave in different directions. The Hillsborough runs to Hillsborough Bay, the Withlacoochee to the Gulf at Yankeetown in Citrus County, the Peace to Port Charlotte, and the Ocklawaha into the St. Johns River near Welaka, according to the Southwest Florida Water Management District (SWFWMD) figures below (SWFWMD).

The St. Johns River, which SJRWMD calls one of the few rivers in the United States that flows north, falls very little. SJRWMD describes a slow 310-mile northerly journey from a marsh in Indian River County to the Atlantic Ocean past Mayport, and says the river drops a total of less than 30 feet from the marshes south of Melbourne to its mouth (SJRWMD).

The incoming tide reverses the St. Johns flow twice a day, and in periods of low water the reverse flow can reach as far south as Lake Monroe, 161 miles upstream from the mouth, and high, sustained northeasterly winds can reverse it for many days; SJRWMD says these are the reasons it is difficult for the Florida river current to naturally flush pollutants (SJRWMD).

Lake Okeechobee and its wetlands sit at the center of the Greater Everglades watershed, which stretches from the Kissimmee River through the Everglades and into Florida Bay (SFWMD, Lake Okeechobee).

The South Florida Water Management District (SFWMD) gives the lake a surface area of 730 square miles, calls it the largest lake in the southeastern United States, and puts its average depth at only 9 feet. The lake drainage basin covers approximately 2.8 million acres, or 4,400 square miles including the Arbuckle Creek sub-basin and the lake itself (SFWMD).

SFWMD says excessive nutrients from agricultural and urban activities in the watershed threatened the lake's health in recent decades. It estimates total phosphorus loading into the lake at approximately 600 metric tons per year, and says four priority basins (S-191, S-154, S-65D and S-65E), about 450 square miles, contribute the highest concentrations and 35 percent of the load, and the majority of watershed projects concentrate on these basins (SFWMD).

SFWMD notes that in 2007 the Legislature expanded the Lake Okeechobee Protection Act to cover the entire Lake Okeechobee watershed, including the Caloosahatchee and St. Lucie estuaries (SFWMD). The Florida Department of Environmental Protection (DEP) groups the Lake Okeechobee watershed with the Caloosahatchee and St. Lucie River watersheds and estuaries as the Northern Everglades watersheds, which have their own set of basin management action plans (DEP BMAPs). SFWMD lists the record of decision for the Lake Okeechobee System Operating Manual as signed August 12, 2024 (SFWMD).

DEP finds Florida waters that fail state standards, lists them as impaired, sets a total maximum daily load (TMDL) for each pollutant, and then adopts a basin management action plan (BMAP) to reach it (DEP TMDL Program; DEP BMAPs).

The work sits in the DEP Water Quality Evaluation and TMDL Program, which has two sections: the Watershed Evaluation and TMDL section, which conducts statewide, basin-scale assessments of surface water quality, and the Watershed Assessment Section. A TMDL is a scientific determination of the maximum amount of a given pollutant that a surface water can absorb and still meet the water quality standards that protect human health and aquatic life. Waterbodies that miss those standards are identified as impaired for pollutants such as nutrients, bacteria, dissolved oxygen or mercury in fish tissue (DEP).

A BMAP turns a TMDL into projects. DEP describes it as a framework with permit limits on regulated facilities, urban and agricultural best management practices, wastewater and stormwater infrastructure and conservation programs, developed with local stakeholders, adopted by Secretarial Order and legally enforceable (DEP BMAPs). Section 403.067 of the Florida Statutes lets DEP, alone or with a water management district, write a BMAP that addresses some or all of the watersheds and basins tributary to the impaired waterbody (section 403.067).

Florida BMAPs come in families: Northern Everglades, springs, nutrient, Indian River Lagoon and fecal indicator bacteria plans. DEP describes the Indian River Lagoon as a 156-mile-long estuary whose impaired portions are directly adjacent to lands in only Volusia, Brevard, Indian River and St. Lucie counties (DEP BMAPs).

Florida law gives three districts restoration priorities: Lake Okeechobee, Biscayne Bay, Lake Worth Lagoon and the Indian River Lagoon system for SFWMD, Tampa Bay for SWFWMD, and Lake Apopka, the Lower St. Johns River and the Indian River Lagoon system for SJRWMD (section 373.453).

Those priorities come from the Surface Water Improvement and Management (SWIM) program in section 373.453, which lets each Florida district develop SWIM plans for waters on its priority list, with a description of the water body, its hydrology and the conditions that led to the need for restoration (section 373.453). NWFWMD says the SWIM Act was enacted in 1987 and that its priority list includes all seven major riverine-estuarine watersheds of northwest Florida (NWFWMD).

Source for the table: the NWFWMD SWIM page (NWFWMD).

In northwest Florida, NWFWMD's new Watersheds Partnership Program selects one priority sub-basin in each of the district's seven major watersheds for focused planning, coordination and funding (NWFWMD).

NWFWMD held public workshops for each of the seven watersheds during October 2025 and took input through online surveys. The sub-basins shown on its page include Mill Bayou-Watson Bayou in the St. Andrew Bay watershed, Lake Jackson in the Ochlockonee watershed, Goose Creek-Dickerson Bay in the St. Marks and Apalachee Bay watershed, Destin Harbor-Hogtown Bayou in the Choctawhatchee watershed, and Bayou Texar and Elevenmile Creek in the Perdido and Pensacola Bays watersheds (NWFWMD).

The district's updated SWIM plans were approved in 2017, one with a 2018 revision, and the district says its SWIM priority list is updated annually in its Consolidated Annual Report (NWFWMD).

Statewide, DEP lists 2025-26 BMAP public meetings and a BMAP meeting calendar where anyone can subscribe to notices, and its BMAP page was last modified October 2, 2026 (DEP BMAPs).

Last verified: October 15, 2026, on the DEP, NWFWMD, SRWMD, SJRWMD, SWFWMD and SFWMD websites and in the Florida Statutes.