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“This is the start of the Peace River,” says King, a biologist at Tenoroc, a 7300-acre recreational outpost near Lakeland, recycled from former mining lands.
The worn structure sits at the confluence of three ditches that carry water from old mining lands, manmade lakes and former clay setting ponds into Saddle Creek, the uppermost tributary of the Peace River, which flows 105 miles south to its terminus at Charlotte Harbor on Florida’s gulf coast.
Across I-4 and just a few miles north is the southern boundary of the Green Swamp, the hydrologic heart of central Florida. From this vast backcountry of more than a half million acres flows a primordial ooze that quenches the thirsty upper tentacles of four rivers: the Hillsborough, Withlacoochee, Ocklawaha and Peace.
Tenoroc is a jumble of disturbed lands, a living laboratory that reveals the evolution of Florida’s mined land reclamation, from its earliest beginnings before 1975 — when the state began requiring that mined lands be put back to productive use — to today. Parts of it were abandoned to Mother Nature, other parts voluntarily reclaimed by mining companies, and still other portions rehabilitated under mandatory reclamation — with varying degrees of success.
Exotic cogon grass runs rampant in some areas, to the dismay of battle-weary biologists. On other plots, research is underway to test reclamation techniques and hasten recovery of native habitats. Some reclaimed and even unreclaimed lands appear to be thriving, at least on the surface. And then there are the lakes, 15 of them in all, former phosphate pits — happy hunting grounds for freshwater anglers in pursuit of largemouth bass.
Tenoroc is a jumble of disturbed lands, a living laboratory that reveals the evolution of Florida’s mined land reclamation. |
“Certainly what was recreated at Tenoroc was not designed with the big system in mind,” says King, who has watched the story unfold from the start.
Not long after earning a graduate degree in wildlife ecology from the University of Florida, King traded a private-sector consulting job for a chance to work on a state team evaluating the phosphate industry’s first mandatory wetland reclamation project, at Clear Springs mine on Peace River’s eastern banks. Twentyfive years later, he’s still on the job, nurturing reclaimed lands in public ownership, while helping to sow the seeds of a massive re-plumbing project designed to increase flows to the Peace.
Tenoroc Over Time
Before strip-mining gouged gaping craters in the land during the middle of the last century, the eastern portion of Tenoroc was part of a vast wetland system at the headwaters of Saddle Creek. Drainage from this natural system also supplemented downstream flushing through the now-degraded Lake Hancock, the largest lake in the Peace River system. Tenoroc’s western edge was part of a wetland complex feeding Lake Parker, which spilled over to Saddle Creek and Lake Hancock.
Today a system of ditches conveys water around and through mined areas, including a series of deep-water phosphate pits teeming with largemouth bass that provide sporting chase to visiting anglers.
Coronet was first in a series of phosphate suitors to strip-mine here, dubbing the site Tenoroc – C-o-r-o-n-e-t spelled backwards. The main tract (6040 acres) – a mix of reclaimed and unreclaimed lakes (former phosphate pits), phosphate clay settling areas, and sand tailings left over from mining and reclamation — was donated to the state in 1982 by Borden Inc. Later acquisition of two smaller former mines increased the lands under state management and a sprawling recreational complex was born.
The site is now managed by the Florida Fish and Wildlife Conservation Commission as a recreational fishing area attracting more than 2000 visitors a month. Bass fishing is the big draw, but Tenoroc’s lakes are also home to black crappie (speckled perch), bluegill, and catfish. Besides fishing, Tenoroc hosts horseback riding, hiking trails and a shooting range.
Fixing the Plumbing
Tenoroc staff is gearing up for an ambitious feat – tying together dozens of isolated reclamation projects into a functional floodplain that sends more water back to the Peace River, where flows have declined by as much as 45%.
The cause of those declines is hotly debated. Some say mining is to blame. Others say long-term weather patterns have robbed streams throughout central Florida of precious rainfall.
A cumulative impact study of activities in the Peace River watershed, begun earlier this year, may provide some answers. “We know there are impounded clay settling ponds all over the place in the upper Peace region,” says King. “To some degree you’d think these clay areas are slowing or eliminating the flows, but we don’t know how serious the issue is, or if it’s responsible for the chronic low flows.”
Restoring Tenoroc will entail connecting stand-alone reclamation projects from three separate phosphate mines, and coordinating land use and drainage on neighboring properties. The Herculean task has already begun.
New wetlands are being built to house more water supply. Clay settling ponds are being connected and outfitted with internal drainage systems and conveyance channels designed to get water flowing again. A main treatment wetland, still in the conceptual stages, will turn water the color of pea soup amber clear by shading out algae. Another pond will be reborn as a 180-acre oasis for migratory waterfowl.
At the same time, Tenoroc officials are working with the Williams Company next door, where the University of South Florida’s Lakeland campus is rising out of the ground, to negotiate access to water idling in lakes and clay settling ponds there.
New wetlands are being built to house more water supply. Clay settling ponds are being connected and outfitted with internal drainage systems and conveyance channels designed to get water flowing again. |
Clay settling ponds have long been the bane of land managers, hogging 40% of the footprint at most mines and severely curtailing post-mining land use. In phosphate mining, massive draglines remove the soil overburden, mine the ore (a mixture of phosphate rock, clay and sand) and send it to a beneficiation plant for separation. The phosphate rock continues on to a fertilizer plant for processing. Sand tailings are put back in the phosphate pit, and a clay slurry is piped to a settling area. While the mine is active, settling ponds play a vital role in reducing groundwater usage by providing water storage.
Reclamation of these settling ponds is a slow process, requiring three to five years for the clays to dry. Even then the soils remain unstable. “It’s kind of like baking a pie,” says Rob Brown with Manatee County’s environmental management department. “You can get a hard crust, but it’s still soft inside,” continuing to settle and compact for many years.
Still, in the terra cotta-hued muck King sees a silver lining. “Clay ponds by their very nature, by virtue of their impermeable soil and high elevation, can be valuable as headwaters,” he says. “The key is to optimize drainage out of these ponds. I believe these clay ponds can be engineered to function in a watershed context.”
Settling ponds are typically reclaimed as pasture, although research by the Florida Institute of Phosphate Research has demonstrated that a variety of row crops, citrus, sod and ornamentals can be grown on the nutrient-rich clay.
Mining pits that are not backfilled with sand tailings are often reclaimed as recreational lakes. The lakes, however, are not a substitute for wetlands because they fail to provide the same habitat, vegetation or ecosystem functions.
Caution: Wildlife Crossing
Another key objective of the Tenoroc restoration plan is to establish wildlife corridors out of disjointed patches of habitat. A north-south travel corridor is envisioned, but taking that from concept to reality will require further negotiations with neighboring property owners and the ability to navigate I-4 without ending up as roadkill.
A wildlife crossing under the interstate was tabled by DOT when the Williams Company proposed a narrow corridor through their development site, which made justifying the underpass difficult. However, King is optimistic the idea will resurface during the next phase of I-4 improvements as the need for a wider corridor gains acceptance.
The wildlife corridor concept draws on a larger conceptual framework established in the state land management plan for an Integrated Habitat Network (IHN). In the early 1990s, Florida’s Bureau of Mine Reclamation developed the IHN plan as a guide for the reclamation of mined lands and the enhancement of unmined lands in the southern phosphate district, covering the floodplains of the Peace and Alafia River systems and adjacent buffer lands. Simply put, the state recognized the need to establish wildlife travel corridors for animals cut off from vital habitat and food sources by development.
To date, approximately 7,600 acres in nine parcels within the IHN have been acquired by the state through settlement agreements or donations. Another 21 parcels identified in the IHN management plan are lands on which conservation easements or agreements are underway, or for which leases have not yet been completed.
About half of the funding for the $10-million Tenoroc restoration is coming from the state’s non-mandatory reclamation trust fund, the other half from DOT as mitigation for highway impacts.
By 2010, officials expect to have completed the replumbing of clay settling ponds and enhancement of surface water treatment. Reforestation is already underway, along with an aggressive effort to reduce upland exotic plant species by 75% by 2015.
“There’s some comfort in knowing that you can get something back that people will come to know and appreciate,” says King. “It’s not the end of the world, but it’s not the world as we know it.”
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