CELINA, Ohio—Signs posted around one of the country’s biggest man-made lakes read: “Danger: Avoid all contact with the water.”
When dangerously high levels of toxins from blue-green algae in Grand Lake were publicized in 2009, many residents and tourists stopped using the 13,000-acre lake in northwest Ohio. Hotel revenue and home values sank for several years as algae bloomed in the state’s largest inland lake.
Greenish water still laps at Grand Lake’s shores, but recent water samples show that the amount of algae-feeding nutrients entering the lake is down significantly. State, federal and private donations covered more than $10 million in projects aimed at improving water quality. More people are boating on the lake again. Grand Lake could now serve as an example for communities with algae problems across the nation, experts say.
Reconstructed wetlands are helping filter excess nutrients fueling algae blooms from the water at Ohio’s Grand Lake, where a decadelong project has worked to restore the local watershed.
A pump diverts an average of one million gallons per day from Prairie Creek.
Several deep pools slow the water flow, allowing sediment and other particles to drop out.
Shallower pools, replete with vegetation, absorb more of the nutrients.
Filtered water flows to Grand Lake.
Algal blooms are on the rise, from Lake Erie to the Florida Everglades. In August, the Environmental Protection Agency listed algae-related beach closures or health advisories in 23 states, and it said other blooms may not have been reported. In 2010, the EPA found that 20% of 50,000 lakes surveyed had been affected by phosphorous and nitrogen pollution, which feeds algae. Last month, three dogs died after being poisoned by algal toxins in a North Carolina lake.
Cleaning up bodies of water choked with toxic algae has proved difficult. The project to repair Grand Lake, once one of the most polluted by algae in the nation, is one of the clearest successes. It shows cleanup is possible, but also expensive and time-consuming.
Residents here hope the warning signs will soon come down.
“It’s not restored yet, but it’s on the road to recovery,” said
an associate professor of biology at Wright State University-Lake Campus in Celina, who has monitored water quality in the lake for five years.