On a hot weekday morning, children studied the ducks swimming in Meadow Lake, while a steady succession of joggers made their way along the bordering trail.

But the idyllic scene in Flushing Meadows Corona Park, the largest public park in Queens, was interrupted by uniquely urban afflictions. Much of the lake shore is inaccessible because walls of phragmites – tough, tall reeds – get in the way. Runners, meanwhile, have to swerve to avoid the many puddles that interrupt their path.

The unnaturally smooth perimeters and uniform depths of the manmade lakes has allowed for invasive species like phragmites to take over. Photo: Allison Maier

Meadow Lake and its sister to the south, Willow Lake, are the forgotten stepchildren of New York City’s failed bid for the 2012 summer Olympics, which start this week in London. New York’s Olympic bid had proposed transforming the manmade lakes into a 2,000-meter rowing course, a project that early reports estimated at around $164 million.

Instead, while other Olympic-born development projects thrive around the city and borough — from Citi Field and Yankee Stadium to the housing developments now under construction in Hunters Point South — Flushing Meadows’ twin lakes remain stagnant. The waters are saturated with phosphorus and nitrogen that would have been kept in check had natural tides remained untouched by human development. Hydrocarbons, nitrates and heavy metals wash down to the lakes in storm water from the Van Wyck and Long Island expressways and the Grand Central Parkway, which ring the park.

The lakes’ pollution is a result of deliberate engineering choices by Robert Moses, mastermind of the 1939 and 1964 World’s Fairs and the park that hosted them. Moses leveled the towering ash heap that had dominated the site for three decades, covered it with a combination of earth, peat moss and mulch, and planted a smattering of trees and shrubs. He created the two lakes by constructing a tide gate to fix water levels and equipping them to capture storm water runoff.

Locked in by the highways, the lakes today are isolated from other natural areas, preventing new species from immigrating. The high levels of phosphorus and nitrogen have promoted dense growth of algae that have, in the past, depleted oxygen and led to mass kills of fish.

These days, about a dozen species of fish, including carp, white perch and pumpkinseed sunfish, have nevertheless managed to survive in the lakes, though the salty conditions, summer heat and isolation from surrounding areas limit the number of species. John Waldman, a biology professor at Queens College, says he is struck by the diversity of the fish populations that have managed to thrive in Flushing Meadows Park despite the conditions there.

“I’ve developed a lot of respect for its sheer productivity,” he said.

Joggers encounter pools of water near Meadow and Willow lakes, run off from surrounding highways and stuck in compacted soil. Photo: Allison Maier

A report commissioned by the Olympic bid committee in 2006 recommended increasing the acreage of wetland area surrounding the lakes and creating a system of alternating wetlands and soils that would improve natural filtration of pollutants in the water making its way to their waters. It noted that plans to dredge the lakes to nearly three times their current depth to create the rowing course would also help clean out the contaminants that have been building up at the bottom of the lakes ever since Moses created them. The report concluded that the only way to improve the lakes’ ecosystems would be to undertake a massive restoration project.

Coauthor Paul Mankiewicz, executive director of the Bronx-based Gaia Institute, says that the lakes’ biodiversity and ecological productivity — the two measures of a healthy ecosystem — will continue to suffer without such restoration efforts. He also sees aesthetic reasons to clean up an area that is “enormously, heavily used” by the residents near Flushing Meadows: “A water body can be an impressionist masterpiece.”

Mankiewicz is not alone in seeing that potential for the lakes. After New York lost the Olympic bid, the city Parks Department used a J.M. Kaplan Fund grant to hire two architecture firms, Smith-Miller and Hawkinson Architects and Quennell, Rothschild and Partners, to develop a strategic plan for Flushing Meadows Corona Park. It recommended that the city dredge the lakes and reconfigure the shoreline — at an estimated cost of close to $18 million — as well as develop programs to deal with water quality and invasive species.

Without the Olympics boost, funds on that scale aren’t to be found, but more modest restoration is proceeding. In July 2010, the city Department of Environmental Protection announced that Unisphere, Inc., a parks conservancy, would receive a grant of nearly $387,000 to carve out wetlands to capture and treat storm water runoff on its way to the lakes. That system’s design is complete and construction is expected to begin this fall, said Meira Berkower, a planning coordinator with the Parks department who is managing the project.

The Natural Resources Group of the city Department of Parks and Recreation is planning its own restoration work for the lake, which will be funded through a state Department of Environmental Conservation grant and local matches together totaling roughly $2.5 million. That effort will focus on shorelines along the west side of the lake, digging out the invasive phragmites and planting an assortment of wetland and meadow plants, like brushes and sedges, as well as trees, said project manager Kathleen McCarthy. The new plantings will help create a more diverse habitat and offer natural filtration to clean the water, she said. The Parks department is also looking into creating a bio-retention basin for storm water and even floating islands in the lake.

McCarthy said work is expected to begin in 2013. In this case, she said, coming up with a plan for the unique situation of the urban lake, with its brackish water and surrounding highways, will likely end up taking longer than the actual restoration work.

“It’s been a very long process for designing this project because it’s a very unusual ecosystem,” she said. McCarthy says she looks at this work as a pilot project that will help refine strategies to be used for the lake in the future.

“I’m really excited to see what happens,” she said. “I think it will be a very interesting restoration.”

In the meantime, Meadow Lake continues to get throngs of visitors who appreciate it for what it is. On August 4 and 5, nearly 200 teams will race over its waters for the 22nd annual Hong Kong Dragon Boat Festival. Meadow Lake is ideal for a rowing event like this because of its large size and lack of big waves, said festival chairman Henry Wan. The lake actually seems healthier now than it was in past years, he said, when oxygen depletion killed fish there. Still, its distinctive green hues have remained the same.

“The color hasn’t changed,” he said.