Wetlands

Wetlands in Miami-Dade County serve vital functions which are essential to the health and welfare of the people of Miami-Dade County. Our wetland areas provide direct recharge of water to the Biscayne Aquifer, the County's sole source of drinking water. The wetlands serve to filter and purify surface and ground waters as well as provide habitat for wildlife, including many rare and endangered species. Their great capacity to absorb water also helps reduce flooding. Additionally, wetlands are often popular destinations for recreational activities, like bird watching, providing an economic and social value. Because of these important functions, wetlands are protected by federal, state, and local regulations.

Wetlands as defined in Chapter 24-5 of the Code of Miami-Dade County often exist within the areas shown on the Wetland Areas of Concern map. However, please note that this map is only an approximate guide. Wetlands are not always easy to recognize. They are characterized by hydric soils such as marl or muck, they often have hydrology that saturates the soil for at least part of the year, and, under normal conditions, wetlands will support vegetation typical of wet conditions. However, it is important to note that wetlands do not always look like those found in the Florida Everglades. Some wetland areas do not always appear wet. Certain disturbed sites are often incorrectly assumed to be uplands, especially when viewed during dry times of the year. Wetlands sometimes appear as disturbed areas that may contain illegally dumped solid waste and may be dominated by non-native invasive vegetation. Wetland areas may also include abandoned, former, or even presently active agricultural sites.

It is recommended that any low-lying property within or close to the boundary lines of the Wetland Areas of Concern map receive verification from the Wetlands Resources Section of DERM on whether the property contains wetlands prior to performing any work. Many existing agricultural properties within the Wetland Areas of Concern map boundaries have biological characteristics or other indicators that classify them as a wetland. In addition, there are sites outside of the map boundaries that may also contain pockets of wetlands.

What are wetlands and where do wetlands exist? The Wetlands Brochure (English & Spanish) will answer many of your questions about wetlands in South Florida and any relevant permitting processes.

For more information on wetlands, call the Wetlands Resources Section at 305-372-6585 or email [email protected].

Coastal, or saltwater, wetlands consist of salt marshes and mangrove swamps. These habitats fuel both terrestrial and aquatic food chains. Wetlands contribute to water quality by removing excess nutrients and pollutants that originated in the uplands before they reach the estuary. Wetlands also offer important habitat for a wide variety of organisms that rely on the area as a nursery ground, and provide protection against coastal erosion.

A Class I permit is required prior to doing any work in, on, over, or upon the tidal waters of Miami-Dade County or any of its incorporated municipalities.

For more information, call 305-372-6575 or email [email protected].

Mangrove swamps are among the most productive ecosystems in world.

Mangrove communities along the coastal areas of Biscayne Bay stabilize bottom sediments and protect shorelines from erosion and storm surge. Forest and fringe communities provide protection from storm surge and can potentially reduce damage to upland areas from hurricanes. Mangrove trees provide nesting and roosting habitat for many resident and migrating birds in addition to providing shelter and a safe nursery to growing marine life. Mangrove leaves are also a large component of the near shore food web.

Development pressures on mangrove wetlands have reduced their size over the last century. With this loss of mangrove wetlands, a subsequent decline in the animal and plant life supported by these ecosystems – including a number of commercial fish - has been documented. In order to better protect this vital ecosystem, the 1996 Florida State Mangrove Trimming and Preservation Act limits the removal and trimming of mangroves on public and private property.

Mangroves are tropical trees that have adapted to salt water and wave activity. There are three species of mangroves in Florida. They are related by the way they have adapted to a mutual habitat, but are actually members of different plant families.

The red mangrove (Rhizophora mangle) is most commonly recognized by its "prop" roots. They sometimes begin very high up on the trunk, arch out and then down into the soil. These roots provide tremendous support for the tree, which is necessary since it encounters repetitive wave action, varying tides, and frequent storms. This root system also allows the mangrove to receive oxygen that is needed for growth that would otherwise not be available from water-saturated soil. Many marine organisms use this root system as a nursery ground and these roots help stabilize the shoreline from erosion.

The black mangrove (Avicennia germinans) root system is opposite of the red mangrove. It extends down into the soil from the trunk and its ends come upward out of the ground, sometimes as much as a foot. These outcroppings are termed pneumatophores, and their function is to exchange gas. This mangrove is often found in the interior of the wetland, where tidal action is not as severe.

The white mangrove (Laguncularia racemosa) can occur almost anywhere in a wetland, but is mostly found in higher elevations, such as the inland edges. The root system can vary depending on the conditions of the wetland and its distinguishing feature is the two glandular openings on the leaf stem.

Another species that can often be found in mangrove wetlands is the Green buttonwood (Conocarpus erecta). This species is a member of the white mangrove family and also resides around the higher elevations of the mangrove wetland. This species is restricted to South Florida due to its frost intolerance.

Southeast Florida’s salt marshes are typically found landward of fringing mangrove forests and at slightly higher elevation than mangroves. This ecosystem is dominated by grasses, grass-like and herbaceous plants, which provide habitat heterogeneity and support a vast array of fish and wildlife.

The dominant plant species are Gulf cordgrass, salt meadow cordgrass, black needle rush, saltgrass, saltwort, perennial glasswort and seaside oxeye.