Lower St. Johns River Basin
The lower basin of the St. Johns River is that portion of the river that extends from Lake George to the river’s mouth at Mayport.
Major contributors of pollution in the lower St. Johns River are partially treated wastewater from utilities, runoff/discharge from agricultural areas, stormwater from urban and suburban areas and nutrients that enter the river in the upper and middle basins to the south. The nutrient-rich discharges have fed harmful algal blooms, which can harm the environment by blocking sunlight to submerged aquatic plants, deplete dissolved oxygen, and impact fish and other wildlife by reducing the quality of the aquatic food chain, and on occasion, producing algal toxins.
Florida’s Surface Water Improvement and Management (SWIM) Act directed the St. Johns River Water Management District to conduct the necessary research to gain an understanding of what is needed to restore and properly manage the river, and to develop a plan for that work.
In addition to its day-to-day work, the district has formed partnerships over the years with local governments, other agencies, stakeholder groups and the public to develop initiatives to restore the river, including the 1998–2003 River Agenda and the 2006 River Accord.
The investments by the district and its partners are the largest in the lower St. Johns River’s history and include a citywide no net-gain goal for septic tanks (Jacksonville/Duval County), a program to improve access to the river, an annual state of the river report and a research program to examine why the river’s tributaries are filling in with silt.
The district is engaged with many local government partners, the Florida Department of Agriculture and Consumer Services, Florida Department of Environmental Protection, Natural Resources Conservation Service, University of Florida’s Institute of Food and Agricultural Sciences and the Northeast Florida Growers Association. Partnership objectives are to contribute to the improved health of the lower St. Johns River through on-farm and regional water management projects and practices that reduce the movement of nutrients to the river, improve water conservation, and result in more efficient farm management while maintaining the long-term viability of agriculture in the tri-county agricultural area.