The fertile muck soils along the south shore of Lake Okeechobee in the Everglades Agricultural Area are intensively farmed. Tomatoes, beans, squash, peppers, and other crops are grown during the winter and shipped north. Sugarcane is the main crop there from spring through the fall.

The bottom center of the later images reveals the location of Stormwater Treatment Area (STA) 3/4, one of six STAs mandated by the State of Florida’s Everglades Forever Act, passed in 1994. STA 3/4 is distinct from the polygons of the agricultural area. Just to its west is Holey Land Wildlife Management Area.

These constructed wetlands are designed to remove phosphorus that comes from agricultural runoff. Under previous agricultural practices, phosphorus from fertilizers was allowed to run off into the Everglades. Phosphorus is an essential nutrient, but too much of it alters the Everglades’ natural habitats.

These treatment areas channel runoff through shallow marshes filled with plants that absorb phosphorus, reducing the amount that flows into the Everglades. The plants include cattail, southern naiad, hydrilla, and algae. These plants continue to absorb phosphorus even after they die and decompose. The underlying limestone layer then holds the phosphorus, providing long-term storage.

Besides helping to restore the Everglades, these treatment areas have become a great home for wading birds, ducks, and alligators. Florida offers hunting and other recreational opportunities at many of these treatment areas.