As surface water moves over Florida's landscape, it drains into channels and forms a weblike network of nearly 1,700 rivers and streams that stretch across the state (Gazetteer of Florida Streams, 1966). Ranging from a few feet to a couple of miles wide, these freshwater veins carve into the limestone bedrock, shaping Florida's distinctive karst topography; they are the lifelines for many of the state's swamps, marshes, lagoons, and estuaries. Rivers and streams transport sediments and nutrients essential for wetland habitats and the native plants and animals that depend on them. Florida's rivers and streams also moderate the salinity of brackish environments and offer a warm winter refuge for migratory and local wildlife, such as the Florida manatee.
In addition to an assortment of commercial and agricultural uses such as avenues for barge traffic and water for irrigation, Florida's rivers offer water enthusiasts a wide spectrum of recreational activities such as swimming, fishing, boating and canoeing, scuba diving, fossil and artifact hunting, and wildlife observation. Millions of tourists and local residents are attracted to Florida's rivers each year. Hundreds of public riverside parks, boat ramps and piers are maintained by federal, state, district, county and city agencies; and by companies and homeowners' associations.
Florida's geology gives each river unique collections of environmental characteristics (water quality, flow, clarity, temperature, and floral and faunal populations).
Geologists classify Florida's rivers into four categories
|Sand-bottom streams are the most common type in Florida. They are characterized by moderate to swift currents and slightly acidic water.|
|Calcareous streams usually orginate from springs. They have relatively colder temperatures, and generally clear alkaline water that is easily penetrated by sunlight and is rich in calcium and nutrients such as phosphorus. As a result, calcareous streams have dense vegetation and diverse animal populations.|
|Larger rivers are characterized by their above-average size. As a result, large amounts of suspended silt and clay create turbid (cloudy) water. Because these rivers flow into the Gulf or the Atlantic, they are occupied by a mixture of freshwater and marine organisms. The largest rivers in Florida are the St.Johns River, the Choctawhatchee River, the Escambia River, and the Apalachicola River.|
|Swamp and bog streams originate from the swamps, bogs and marshes commonly located in the coastal lowlands. Swamp and bog streams have slow currents. They have dark acidic water with a large amount of suspended organic matter and tannins. The brown or tea color results in the common name "blackwater river". The dark water limits light penetration and therefore reduces plant growth; reduced plant populations results in less diverse animal populations.|
Some of Florida's rivers disappear underground and drain into a subterranean limestone labyrinth of aquatic caves. The notable Santa Fe River disappears underground at O'Leno State Park and reemerges at River Rise Preserve State Park, 3 miles away. Visitors at Falmouth Springs can watch groundwater emerge from a spring to create a short river that siphons underground, a mere 500 feet away.
Like all surface waters in Florida, the state's rivers have been classified according to their designated uses, and are arranged in order of the degree of protection required.
Water quality guidelines developed by the Florida Department of Environmental Protection (FDEP) provide use standards (Florida Administrative Code 62.302.5.0). These guidelines provide different water quality standards for five classes of waterbodies defined by their respective designated uses:
- Class I Waters: Potable Water Supplies
- Class II Waters: Shellfish Propagation Or Harvesting
- Class III Waters: Recreation, Propagation And Maintenance Of A Healthy, Well-Balanced Population Of Fish And Wildlife (The Surface Waters Of The State Are Class III Unless Described In Rule 62-302.400 F.A.C.)
- Class IV Waters: Agricultural Water Supplies
- Class V Waters: Navigation, Utility and Industrial Use.
Florida's river systems support a wide variety of native animals. Each year, wildlife observers canoe the waterways or hike along waterside trails for the opportunity to observe Florida's native river denizens. Alligators, wading birds, manatees, frogs, fish, otters, beavers, and turtles are a few of the creatures that occupy and depend on our river environments.
One reason for Florida’s animal diversity is the state's slow-moving rivers and their wide variety of plankton. Plankton are the beginning of the food chain and a source of food for many aquatic animals. A diverse plankton population creates a diverse food chain.
Aquatic animal diversity plays an essential role in river ecology. Bottom feeders such as nematodes break down plant matter. Shellbuilders, such as snails, process calcium in the water. Alligator holes provide all animals with water during drought. River ecology revolves around a web of interactions based on production and consumption.
Trees and aquatic plants play an integral role in river ecosystems by filtering out pollution and sediments, and offering shade, nursery areas, food, shelter, and nesting sites to many kinds of river animals. Several hundred species of native aquatic plants may live in Florida's rivers and along their shores, including submersed (underwater) plants; emersed (growing above the water) plants; floating-leaved and free-floating plants; and grasses, sedges and rushes. Learn more about Florida's native aquatic plants. The table below shows some native plants that are especially common in Florida's lakes and streams. (The pictures link to more information about each plant).
Sometimes, rivers become infested with non-native invasive aquatic plants such as hydrilla, water hyacinth, and others. When this happens, the plants must be controlled to preserve water quality guidelines. The Florida Fish and Wildlife Conservation Service, Invasive Plant Management Section is responsible for managing plants in all public waters. For information about various methods of aquatic plant control in Florida, go to Section 3 of this web site.
As Florida’s population grows, Florida's river systems are increasingly threatened by over-use, pollution, development and invasive species. In 1998, the U.S. Environmental Protection Agency assessed approximately 5,000 miles of Florida's rivers and streams. The EPA report said that 7 % of the 4,947 miles assessed does not support aquatic wildlife and recreation, and 37% only partially supported these uses. Of 772 miles assessed for fish consumption, 20% were not supporting their designated use for fish consumption, and the remaining 80% were only partially support this use.
A wide variety of factors can disrupt a river's natural ecosystem. Among other things, the health of a river's ecosystem is affected by activities within the surrounding watershed. Most often, disruption and destruction of the natural river environment is a result of human activity. Pollution, physical alterations, invasive species, removal of native vegetation, drought and groundwater depletion, and unmanaged recreational activities contribute to the changes in a river’s environmental quality. Learn more about human impacts on Florida's water resources.
Enjoy the recreational opportunities that rivers provide, but be a good steward of these resources. Remember that rivers are not indestructible. Florida’s acquisition programs for conservation and recreation, especially the Save Our Rivers Program, have an uncertain future. These and other important efforts are crucial to conserve Florida’s water resources for current and future generations.