No doubt you’ve visited Baker’s Lake in summer to watch herons, egrets, and cormorants raising their young on man-made nesting platforms and in the recycled Christmas trees painstakingly placed there every year by the Citizens for Conservation.
Recently it’s been discovered that E. coli has been found in the waters of Flint Creek, which is in the same watershed as Baker’s Lake.
Because both bodies of water are in the same watershed, some officials have said the nesting birds’ guano deposits could be contributing to the pollution, according to Tom Benjamin, a member of Citizens for Conservation who helps manage Baker’s Lake along with the Cook County Forest Preserve District. To understand why that’s a possibility and whether these birds are to blame, we need to understand what a watershed is.
We all live within a watershed—an area where water drains from the surrounding land into lakes, rivers, and streams. Think of a watershed like a cone with scattered bumps. What you pour at the top of the cone runs downstream into other parts of the cone, collecting at various points in streams and lakes, becoming concentrated in certain areas, but not others.
Nonpoint source pollution is a fancy term that means some chemical or other substance has come from some place within the watershed and collected in another area.
Perhaps the guano coming from the birds at Baker’s Lake is traveling to Flint Creek. But that may not be the case, says Robert Sliwinski, senior wildlife biologist for Burke Engineering Ltd., which created and constructed the man-made nesting structures for the birds at Baker’s Lake.
There’s a golf course in the watershed—and lots of geese hang out on the course – they could be contributing, he says.
The only real way to find out is to do specific studies for a year and measure the levels of E. coli.
“We can’t make an assumption about where it’s coming from until there are some sort of observations made,” Sliwinski says. “And the question that remains is are the numbers high enough to cause a problem?”
Those studies would mean gathering water samples at specific points within the watershed—at Baker’s Lake, for example, and testing them for pollutants at different times of the year. Finding the source of pollution can be challenging.
You’ve also no doubt heard that it’s the fault of gulls when Lake Michigan beaches get closed due to an overabundance of E. coli. As usual, there’s always more to the story. Humans use the beach too—do they feed the gulls and encourage more to come? What could be other sources of the E. coli?
Of course, we don’t want pollution in our lakes, streams, and rivers—but we need to be cautious about making quick assumptions regarding blame. We need to wait for the studies to be done and then discuss various solutions, if needed.
We can also consider what we can do to keep our lakes, rivers, and streams clean—even if we don’t live on one—because we still live in the watershed that feeds into those bodies of water.
Excessive use of lawn fertilizers can contribute, as can chemicals used to treat pests on farms or in gardens, or coal tar used on blacktop, or throwing garbage into a ravine. Stopping any of those practices is one step.
Owners of expansive lawns—especially corporate lawns and ponds—should consider converting large grassy areas to native plantings, which would absorb pollution as well as deter geese. Geese prefer short grassy areas with ponds—if the ponds are surrounded by taller vegetation, they probably won’t stay.
We can also create rain gardens in key spots on our property—a patch of native plants that love being wet and help trap pollutants before they reach streams, lakes, and rivers. Indeed, conservation-oriented residents at Diamond Lake have created rain gardens along the lake to trap pollutants—and the College of Lake County has installed what are called bioswales to trap pollutants coming from streets.
These are not only practical solutions, but beautiful ones as well.