In this section
- History of Lake Apopka
- Lake Apopka Marsh Flow-Way
- Lake Apopka North Shore
- Gizzard shad harvesting at Lake Apopka
- Continuous sensor-based water quality data
- Map of the regions (flood control areas) where water control structures operated by the district are designed to reduce flood impacts
Lake Apopka shad harvesting
- Setting Water Quality Goals for Restoration of Lake Apopka: Inferring Past Conditions (technical report)
- Total Maximum Daily Load for Total Phosphorus for Lake Apopka, Lake and Orange Counties, Florida (technical report)
- Florida Fish and Wildlife Conservation Commission aquatic plant management strategy for Lake Apopka
History of Lake Apopka
Photos courtesy of the Florida State Archives.
Located in northwest Orange and southeast Lake counties, Lake Apopka is the headwaters of the Harris Chain of Lakes. Lake Apopka is fed by a natural spring, rainfall and stormwater runoff. Water from Lake Apopka flows through the Apopka-Beauclair Canal and into lakes Beauclair and Dora. From Lake Dora, water flows into Lake Eustis, then into Lake Griffin and then northward into the Ocklawaha River, which flows into the St. Johns River.
Lake Apopka was once a world-class bass fishery. However, the lake was named Florida’s most polluted large lake following a century of abuse that began in the 1890s with construction of the Apopka-Beauclair Canal that lowered lake levels by a third.
In addition, the decline of Lake Apopka can be traced to:
- The loss of 20,000 acres of wetlands along the lake’s north shore to farming operations beginning in the 1940s
- Agricultural discharges laden with phosphorus until the late 1990s
- Treated wastewater discharges from shoreline communities prior to the 1980s
- Discharges from citrus processing plants prior to the 1980s
The increase in nutrients discharged into the lake led to a chronic algal bloom, and Lake Apopka’s waters turned pea green. The cloudy water prevented sunlight from reaching underwater vegetation critical to fish and wildlife habitat.
The continual settling of dead algae created a thick layer of soupy muck, which also destroyed the habitat necessary for fish and wildlife to thrive. The bass population significantly declined as gizzard shad became the predominant fish species in the lake. Once the bass disappeared, all the fish camps closed.
Downstream to the north, the pollution spread throughout the Harris Chain of Lakes. To protect the Harris Chain, the flow of pollutants from Lake Apopka had to be stemmed.
Restoring Florida’s most polluted large lake has been challenging. An estimated 676 birds died on former farms at Lake Apopka during late 1998 and early 1999. Most were American white pelicans, wood storks and great blue herons. Organochlorine pesticide (OCPs) residues remaining from agricultural practices were the primary cause of bird deaths. Birds accumulated OCPs by consuming contaminated fish. The St. Johns River Water Management District has conducted research to better understand the accumulation of OCPs through the food chain, from contaminated soil to fish, and from fish to fish-eating birds. The knowledge generated guides restoration of the former farmlands at Lake Apopka and is applicable to other projects designed to restore ecosystems impacted by agriculture.
The Lake Apopka Restoration Act of 1985 and Florida’s Surface Water Improvement and Management (SWIM) Act in 1987 paved the way for restoration work to begin. A SWIM plan outlines restoration activities.
The primary goals for the restoration of the lake’s ecosystem are to:
- Reduce the amount of phosphorus going into Lake Apopka
- Remove phosphorus and other suspended sediments from the lake (by filtration through the marsh flow-way and by mass removal of gizzard shad)
- Improve the food-web structure by removing gizzard shad
- Restore habitat through restoration of the lake shoreline, increased fluctuation in lake levels and restoration of the north shore farmlands to wetlands
The district’s Governing Board approved a rule in 2002 limiting the amount of phosphorus that can be discharged into Lake Apopka or its tributaries as a result of new construction in the lake’s watershed. The district has collaborated with local, state and federal agencies to:
- Purchase agricultural land along the lake’s north shore, reducing the discharge of phosphorus from the farms and providing an opportunity to restore the former marshes to wetlands
- Operate the marsh flow-way, which removes total phosphorus from Lake Apopka water
- Harvest gizzard shad, removing phosphorus and nitrogen in fish tissue from the lake
- Replant six native wetland species of vegetation in the water along the lake’s shoreline, which helps restore fish and wildlife habitat
- Work with the Friends of Lake Apopka and the East Central Florida Regional Planning Council to develop a plan to ensure that future development does not negatively impact the lake
Posted on 1-28-2013