New life for Lake Maggiore

Published March 26, 1996|Updated Sept. 15, 2005

The exact date is unknown, but at some point during the late 1980s, it happened: The last water skier climbed out of Lake Maggiore coated in a disgusting slop, threw the skis in the back of the boat and never came back.

No surprise there. The average depth of Lake Maggiore is about eight feet. That's four feet of water atop four feet of muck _ a ketchup-thick mixture of decaying organic material laced with pollutants.

Lake Maggiore is a mess _ wisely avoided by swimmers, water skiers, most fishermen and many fish. The alligators seem happy with it, though. The gator population is described as very healthy.

Cattails, the final insult to a dying lake, threaten Maggiore on all sides. If not cut back from time to time, they would soon cover the lake and drink all its water, eventually transforming lake to land.

But that's not the Lake Maggiore that Michael Link sees in his mind's eye. Link sees a lake reborn, filled with happy weekend boaters and successful fishermen. He sees water skiers skittering over the surface, just as he did as a boy growing up in St. Petersburg. He sees a waterfront park filled with moms and dads and the noise of children.

Link is St. Petersburg's stormwater utility manager. It's his job to oversee a $10-million plan to save Lake Maggiore, the tab to be split evenly by the city and the Southwest Florida Water Management District.

Here's the problem, and the plan to solve it.

Like many urban lakes in Florida, Lake Maggiore (pronounced locally Ma-GOR-ee) is a victim of storm water runoff. Maggiore is the drainage basin for more than 3,000 acres of residential development, and the pampered greens and fairways of the Lakewood Country Club. Over time, the lake's nutrient "load" _ phosphorous and nitrogen _ has been boosted by fertilizers draining into the lake.

Some nutrients in the water are necessary for life. Too much nutrition and the plant biology gets out of whack.

The water fills with algae and larger water plants, turning it green. When these plants and algae die, their decomposition consumes oxygen in the water, often killing fish. Lake Maggiore has a long history of fish kills brought about by explosions of algae growth, called "blooms."

Over the years, plant and other organic materials have settled on the lake's once sandy bottom, creating a thicker and thicker layer of muck and reducing the amount of water available to fish and other wildlife.

To break this cycle, the city plans to construct four treatment areas, or settlement ponds, around the lake. Stormwater runoff will be directed into these ponds through storm drain pipes.

While the water is in the pipes, alum, a coagulant, will be added to the water. The alum will attach to nutrients and other pollutants, causing them to sink to the bottom of the pond. The cleaner water then will be allowed to enter the lake.

One settlement area will be an existing pond at the northwest corner of the lake. Three others already exist as water hazards on the Lakewood Country Club golf course. The club is "100 percent" behind the plan, said general manager Peter Petersen.

"We've been assured the effects on the lakes will be minor," Petersen said. "In fact, we think the lake water will be blue and pretty, and it will add to the overall beauty of the golf course."

The settlement ponds will remove 90 percent of the phosphorous, heavy metals and solids from the water, perhaps half the nitrogen and 99 percent of the bacteria, said Harvey Harper, president of one of the city's environmental consulting firms.

The really big job in the restoration of Lake Maggiore will come in a year or 18 months, when workers begin dredging the vast muck bottom of the 375-acre lake.

Although no permits have been obtained, current plans call for a floating dredge to pump water and sediment to a temporary shore facility where water would be removed. The sediments then would be pumped or trucked to several old borrow pits around the city.

The sediments are not odoriferous or harmful, Link said. "The real problem is trucking expense." The cost of the dredging project is estimated at about $6-million.

It isn't realistic to think of scrubbing out the lake like a bathtub, right down to its sandy bottom, said Link. A minimal goal will be to take out the top three-quarters of the muck, he said. "That's the worst, the stuff most easily stirred up and suspended in the water," he said.

Once clean, will the lake stay that way?

"We think so," said Harper, president of Environmental Research and Design in Orlando. "Our modeling indicates the lake should be able to hold its own, if inputs (pollution and runoff) are controlled. It looks very hopeful."

Despite the optimism, and the $10-million, Lake Maggiore is not promised a long and healthy life. Urban lakes with nutrient and pollution problems are common in Florida, and saving them isn't easy, said Tom Champeau of the Florida Game and Fresh Water Fish Commission.

Scientists measure the health of a lake on a Trophic State Index, or TSI. The higher the reading, the more trophic, or nutrient-rich, is the lake.

Lake Maggiore's TSI is in the low 80s _ an unhealthy reading. Lake Tarpon has been typically a 45 or 50 over the years, said Champeau, a good reading. But today, he said, Lake Tarpon "is pushing 60, due to development in the northern part of the county. That's up 10 or 15 points in the last 20 years."

Conditions do get worse, however.

Until recently, Banana Lake in Polk County "was off the scale at about 105," said Jeff Spence, the county's director of natural resources. Another Polk County lake, Hollingsworth, had as much as 15 feet of muck in some places, he said.

With all its problems, Lake Maggiore actually supports a modest population of fish, Champeau said. But not many of the kind fishermen favor.

There are tilapia (Nile perch), "and gizzard shad in abundance," he said. "And there are some mullet and a few snook and redfish in there. But bass and quality-size sport fish are in very low density."

Jim Renner, 73, has lived a few blocks from Lake Maggiore _ "same house, same woman" _ for 54 years. He grew up in the neighborhood, and remembers walking down to a clean Lake Maggiore with his dad. He remembers dragging large snapping turtles from the lake and hauling them home in a wheelbarrow.

He remembers killing two ducks with a single shot from his .22 caliber rifle, and watching helplessly as a bald eagle swooped in to carry both away _ one in each talon.

Renner fishes nearly every day, but no longer in Lake Maggiore. "Haven't been there in many years," he said. "Why? No reason to."

It would be nice, he said, to see the lake again the way it was when he was a boy.

"It would be nice to see all the people there again," he said.