Southern Landing Wetlands is a 2-acre, man-made wetland that was created to help reduce pollutant loading from the Hollingsworth watershed. Lake Hollingsworth is a 352-acre natural lake with an approximate watershed area of 1600 acres.
This wetland intercepts stormwater runoff from a 66-acre subbasin (part of a watershed) that includes runoff from residential areas and from Florida Southern College. There is no physical cache at this location, you must complete the requirements listed below.
Roads, driveways, parking lots and buildings are impervious areas. When it rains the rain water can’t soak into the ground below these areas, so it flows off becoming stormwater runoff. As the rainfall flows across impervious areas it picks up pollutants, such as oils, greases, litter, leaves, fertilizers and pesticides. This runoff, if not treated, can carry these pollutants to our streams, lakes and rivers. Stormwater runoff is now the State of Florida’s largest water pollution source for our lakes, streams and rivers. The conversion of flatwoods, wetlands, sandhills and prairies to rooftops, roads and parking lots has created a layer of impervious surface on the landscape that has drastically altered the water cycle. This alteration reduces the amount of rainwater that infiltrate into underground aquifers, increasing the amount of stormwater runoff. As the percentage of impervious cover in a watershed increase, the stormwater pollutant loads increase.
Wetlands help with flood control by soaking up stormwater runoff and slowing down stream flow. Wetlands trap sediments that are washed off land or carried in streams. Wetland plants and soils also absorb pollutants such as fertilizer and toxic material, thereby helping with water purification. This wetland contains deep bays that receive runoff from existing pipes that drain the sub-basin. Heavy particles such as sand will settle in these bays. Once the stormwater leaves the deep bays, it flows across shallow marshy shelves that are planted with aquatic vegetation.
Wetlands also provide refuge and habitat for animals and plants, some of which are very rare. For humans, wetlands provide a wonderful outdoor classroom, offering such opportunities as bird watching, photography, and nature walks. The wetlands provide a welcome refuge away from the hustle and bustle of the city.
Native aquatic plant communities provide oxygen, food and shelter for fish and other wildlife. These plants help prevent soil erosion and help clean our water by filtering out some of the pollution. A natural diversity of these plants is important to having a healthy lake, pond, stream or wetland. Aquatic plants growing around the shoreline of this wetland include Giant Bulrush, Soft-Stem Bulrush, Spatterdock, Eel Grass, Lance-Leaf Arrowhead, Golden Canna, Pickerelweed and Bald Cypress trees.
Lake Hollingsworth and the wetlands also provide visitors with an opportunity to see and enjoy a variety of wildlife, including Wood Storks, Moorhens, Great Egret, Great Blue Heron, Marsh Rabbits, snakes and alligators.
To claim credit for this earthcache email your answers to questions 1 and 2 to the email address on my profile.
1. Find the flood control structure on the southern end of the wetland. Estimate the width of the flood control structure. Was water flowing over the structure at the time of your visit? E-mail me your answer.
2. In your own words, how does this wetland filter out harmful chemicals from the surrounding area and keep it out of the watershed? E-mail me your answer.
Sources: Southwest Florida Water Management District; City of Lakeland, Stormwater Division