A Journey on the St. Johns River:
Entering the middle basin

This is the fourth part of a series about the St. Johns River. Each installment explores one of the river’s three distinct basins. In parts one, two and three, we explored the entire extent of the marshy headwaters of the north-flowing St. Johns River, a region known as the upper basin. During this leg of the journey, we pass through several major lakes that form the Middle St. Johns River Basin.

Entering the middle basin

The morning sun crawls above the eastern horizon and begins to simmer the St. Johns River and the surrounding marsh. We travel north, passing beneath the State Road 46 bridge in Volusia County as we enter the Middle St. Johns River Basin. St. Johns River Water Management District Land Manager Graham Williams pilots our airboat deftly through sweeping curves as we make our way toward Lake Harney.

Like many of the shallow lakes strung together like pearls within the St. Johns River, Lake Harney is a saucer rather than a soup bowl. The nine-square-mile lake has an average depth of a mere seven feet. Large waterfront homes front the southwest shoreline of the bean-shaped lake, but a rich, green canopy defines most of Harney’s horizon. The lake’s surface is an expanse of cobalt, reflecting clouds that seem airbrushed in place.

The northern end of Lake Harney morphs into a river channel that slips past the mouth of Deep Creek, snaking its way vaguely northwest past pines, cypress and sabal palms. The river wiggles southwest for a spell — flowing past private campsites, stately homes and long stretches of wilderness. Finally, we reach a fork in the river that begs the question: Travel south to Lake Jesup or continue northwest to Lake Monroe? Because Lake Jesup changed radically over the past century and is the focus of several District restoration studies and water quality improvement projects, we turn south to investigate.

The plight and rebirth of Lake Jesup

Visually, Lake Jesup could easily be mistaken for Lake Harney: a broad expanse of open water, big skies and a relatively undeveloped, marshy shoreline. The largest lake in Seminole County, Lake Jesup covers 25 square miles and stretches 13 miles south. The lake expands into a large floodplain during the wet season. However, unlike Harney, which is contained within the flow of the St. Johns River, Lake Jesup is linked to the river like an appendix, its circulation hampered by its manmade uncoupling from the main river channel.

Since 1990, the District has worked with many partners — including the Florida Department of Environmental Protection (DEP), Florida Fish and Wildlife Conservation Commission, Volusia and Seminole counties and a grassroots organization called The Friends of Lake Jesup — on cooperative projects to improve the lake’s water quality.

Click the map below to see images of the Middle St. Johns River Basin.

Map if the St. Johns River middle basin

Lake Jesup’s water quality decline can be traced to the 1890s, when the steamboat industry began altering the river channel at the mouth of Lake Jesup to improve navigation to Lake Harney. The U.S. Army Corps of Engineers later created Government Cut, a channel that allowed the river’s flow to completely bypass Lake Jesup. Later, a railroad causeway would further isolate the river and Lake Jesup. A historical marker at the Cameron Wight Park and Boat Ramp outlines the impacts of steamboat travel on the storied lake.

“After the channel was cut, it changed the flow patterns to Lake Jesup, impacting its water quality,” says Pam Way, a District environmental scientist who has been working in the middle basin for five years. “Over many decades, modifications in the middle basin due to population growth and the associated stormwater runoff — combined with Lake Jesup’s inability to circulate water into the St. Johns River flow — helped shape the decline in water quality in the lake.”

Following the Lake Jesup Act of 1994, the District initiated diagnostic investigations into the lake’s water quality issues. District scientists conducted water quality sampling and hydrologic modeling of Lake Jesup and worked with partners on projects to turn the lake around. DEP led efforts to reduce wastewater disposal to Lake Jesup’s tributaries in the 1980s and then developed a Total Maximum Daily Load (TMDL) and Basin Management Action Plan (BMAP). Through the BMAP process the numerous local governments in Lake Jesup’s watershed have implemented projects that reduce the volume of nutrient-laden stormwater flowing into the lake.

In 2002, the Middle St. Johns River Basin Surface Water Improvement Management Plan (SWIM) enabled the District to expand its course of action throughout the entire middle basin of the river. The District partnered with Volusia, Seminole and Orange counties on water quality improvement projects, including scores of legislatively funded projects that capture, retain or treat stormwater before it can reach the St. Johns River.

In 2020, the District launched the Lake Jesup Nutrient Reduction and Flow Enhancement Project, which includes components to address both water quality and flow. The nutrient reduction component will be a recirculating wetland treatment system made up of ponds and wetlands to capture and treat nutrient-laden lake water pumped from Lake Jesup. The flow enhancement component focuses on improving water clarity by introducing additional water flow from the St. Johns River via the construction of an inflow channel, known as Channel C, along a route where the river is believed to have historically flowed into Lake Jesup.

The overall project is expected to enhance the historical hydrologic exchange between the eastern portion of Lake Jesup and the St. Johns River, improve fish and wildlife habitat as well as submerged aquatic plant habitat, Way says.

In addition to water quality improvement projects, the District has purchased more than 6,200 acres of land around Lake Jesup, parcels collectively known as the Lake Jesup Conservation Area. This property protects thousands of acres of floodplain marsh habitat that are a haven for migratory birds and a huge draw for birders during the migratory season.

As we cross Lake Jesup, Land Manager Williams maneuvers the airboat to the northern shore where we encounter a wall of invasive reedy grass, roughly 15 feet in height, called phragmites. Phragmites overtake other plant species, displacing the diverse ecosystem needed to support a variety of wildlife.

“The District has worked with Seminole County’s Watershed Management Division to diversify large areas of phragmites,” Williams says, guiding the airboat to an open area where alligator flag, pickerel weed and other native species now thrive. “Everything you saw before was a solid wall of phragmites. Everything you see here now was planted, creating open areas for wading birds and ducks as it was before phragmites took over.”

Lake Monroe

We leave Lake Jesup and push forth into the river channel as we make our way toward Lake Monroe. We pass through a series of curving, liquid alleys until we reach a stretch of shoreline that could be used on a postcard promoting natural, old-time Florida.

The river widens, showcasing a vast floodplain marsh to the north, a 7,400-acre District property called the Lake Monroe Conservation Area. Palm trees with giant root balls dot the shoreline. Cows loiter in the green shadows of oak trees, egrets perched in their branches or in the grass close by.

“Lake Monroe Conservation Area borders more than three miles of Lake Monroe and the St. Johns River, providing water quality and flood protection,” Williams says. “Our conservation areas along the river provide critical buffers between rapidly encroaching development and important wetland areas.”

Continuing north, we pass beneath the graceful concrete-and-steel Douglas Stenstrom Bridge that carries State Road 415 over the St. Johns River (also known as the Osteen Bridge).

The river, isolated from major population centers for much of this trip, broadens to become the shimmering, blue expanse known as Lake Monroe, where the port at the city of Sanford twinkles on the southern shoreline. In the distance, Lake Monroe’s surface shimmers like a mirage. To the north lie Debary, Deltona and the historic village of Enterprise, where indigenous Floridians left behind artifacts dating back more than 6,000 years. (See sidebar on this page.)

The Lake Monroe area and Enterprise share a rich history. Spanish explorer Pedro Menendez visited the region in 1565; so did three U.S. presidents. Writer Harriet Beecher Stow wrote about the area in her book, “Palmetto Leaves,” published in 1873. Cindy Sullivan, director of the Enterprise Preservation Society and chairman of the River of Lakes Heritage Corridor, shares a bit of this history.

“This river made it possible for central Florida to develop,” Sullivan says. “Enterprise had a bigtime downtown in the 1800s, with hotels, ballrooms, stores and even horse racing on the main street.”

Crossing the broad expanse of Lake Monroe, we see the Interstate 4 bridge coming into focus and just beyond it, the State Road 17 bridge. The air temperature is noticeably cooler as the airboat skims across the open water. Immediately downstream of the Interstate 4 bridge, Lake Monroe’s shoreline narrows to become the St. Johns River once again.

The river meanders north, soon reaching a liquid landmark that represents the boundary between the river’s middle and lower basins: the convergence of the Wekiva and St. Johns rivers. Looming ahead lies Florida’s second-largest lake, but first is a reach of the St. Johns influenced by contributions of many springs: Geneva Springs, the Wekiva system, Volusia Blue Spring, Alexander Springs and DeLeon Springs.

Enterprise, jewel of the
middle St. Johns River’s past

Imagine trying to reach central Florida from the coast in the 1800s. Swarms of bloodsucking mosquitos, impenetrable vegetation and tropical humidity were just some of the challenges travelers faced before the advent of decent roads. It’s no wonder that the St. Johns River became a liquid highway as steamship travel flourished in the mid- to late 1800s.

The Middle St. Johns River Basin — particularly the area surrounding Lake Monroe — attracted explorers, writers, hunters, entrepreneurs, tourists and three U.S. presidents as steamships made the region more accessible.

One of the burgeoning communities during this period was Enterprise, a town on the north shore of Lake Monroe.

“Enterprise and Sanford were two big port cities during the steamship era,” says Cindy Sullivan, director of The Enterprise Museum and chairman of the River of Lakes Heritage Corridor. “In Enterprise, the Brock House Hotel attracted celebrities from all over the world, including presidents Hayes, Cleveland and Grant, Jay Gould, the Vanderbilts, James Rockefeller, author and abolitionist Harriet Beecher Stowe and General William Sherman.”

Looking further into the past, the history of the area can be traced back more than 6,000 years, when native Floridians lived in settlements along the banks of the St. Johns River.

In 1565, under explorer Pedro Menendez, the Spanish may have come as far upriver as Lake Monroe searching for the headwaters of the St. Johns River. Two centuries later, explorers and botantists John and William Bartram passed through Lake Monroe also seeking the river’s headwaters.

“Of course, there was the Spanish occupation in the 1500s and then the English,” Sullivan says. “During the second Seminole Indian War, there was Fort Mellon in Sanford and Fort Kingsbury in Enterprise.”

Enterprise was a bustling community, replete with a church, stores, hotels, spas and a pier linking steamboat passengers to a railway. The rail-pier, where five steamboats a day once docked, was located just west of Broadway Street. By 1887, travelers in Enterprise could access the Jacksonville Tampa and Key West Railroad by a spur from Enterprise to Enterprise Junction. The advent of these rail lines spelled the end of the steamboat era.

Enterprise also served as the county seat for three different counties: Mosquito, which was renamed Orange; and for Volusia, which was formed from part of Orange County.

Today, the only remaining building from early Enterprise is the nearly 140-year-old All Saints Episcopal Church, a Florida gothic structure constructed entirely of virgin timber, longleaf and curly pine and cypress. The church is listed on the U.S. National Register of Historic Places.