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The Myakka River Watershed Initiative is a comprehensive watershed study and planning effort designed to develop strategies to protect, enhance and restore natural systems and water quality, while addressing issues of water supply and flood protection.
The initiative is funded and administered by the District and assisted by its consultant team led by Singhofen and Associates, Inc. As part of the District’s Watershed Management Program, the project will measure the effectiveness of recommended strategies to reach the desired watershed condition through assisted decision making using data analysis, modeling, projection and evaluation.
Location
The Myakka River spans about 66 miles from Myakka Head to its outfall in Charlotte Harbor and drains an area of approximately 600 square miles. The Myakka River Watershed is located in portions of several counties including Hardee, Desoto and Charlotte with the majority of the watershed located in Manatee and Sarasota Counties. Just downstream of Myakka Head, seven tributary creeks converge to form Flatford Swamp. Further downstream from the swamp, the river flows through Tatum Sawgrass Marsh before reaching the Myakka River State Park which includes approximately 12 miles of the River. The River flows through both the Upper and Lower Myakka Lakes within the boundaries of the park. Deer Prairie Creek and Big Slough (or Myakkahatchee Creek) both discharge to the River as it widens and enters Charlotte Harbor.
Characterization
Cattle ranching and other farming dominate the majority of the basin especially upstream of the Myakka River State Park. Wetlands comprise approximately 20% of the watershed, half of which are freshwater marshes. Urban areas represent less than 10% of the watershed and are located predominately in the lower portions of the watershed (e.g Port Charlotte and City of North Port). Urbanization is expected to increase throughout the watershed as farmland is converted into residential.
The watershed possesses several unique and important natural and manmade surface water features such as Flatford Swamp, Tatum Sawgrass marsh, and the Upper and Lower Myakka Lakes. The watershed can be generally described as a very slow and meandering riverine system, with a wide range of flows. Flat to moderate slopes along with poorly drained soils through the watershed result in large "pooling" areas (Flatford Swamp and Tatum Sawgrass marsh) and wide flood plains. Through the Sarasota County segment, the Myakka River was designated an Outstanding Florida Water by the Florida Department of Environmental Protection including the estuarine portions, and named a Wild and Scenic River by the State of Florida in the late 1980s.
Why the Initiative is Being Undertaken: As early as the 1930s, alterations have been made in an effort to manipulate flows of the river and its tributaries to control flooding and provide for agriculture and land development. Many of these alterations have had significant unintended consequences.
Examples of the types of alterations that have occurred include:
- A concrete weir constructed across the river at a large widening known as the Upper Myakka Lake for the purpose of stabilizing water surface elevations for recreation
- Dikes constructed along Tatum Sawgrass marsh (north of Myakka River State Park) for the purpose of reducing flood stages in agricultural lands
Over the past several years, there has been increasing interest in restoring areas of the watershed that have experienced environmental damage as a result of these alterations. Because the watershed lies within the Southern Water Use Caution Area (SWUCA), water supply is also a major issue for the area. Especially important to the District’s Regional Water Supply Plan and SWUCA Recovery efforts is the identification of alternative water supplies.
As a result, the District has undertaken the Myakka River Watershed initiative in order to develop and implement a strategy to restore the environmental damage that has occurred in the watershed in ways that can also provide a benefit to water supplies in this critical area.
