One thing is for sure: Chicago would not have grown to be the size it is without the lake. Chicago's population grew exponentially because of its location; it was easy to get to by boat in addition to being a major railway hub. During the Industrial Revolution, commerce passed through by boat and train from both the east and the west, making Chicago a major stopping-off point for industry. And because of this, it grew into not only the largest (and best) city in the Midwest, but also the third-largest in the nation, and it's mostly because of the lake, which made Chicago easily accessible. Looks like we owe the lake some respect.

Those who love the snow can thank the lake for lake effect snow, as it tends to snow more in the city than it does in outlying areas. Everyone's heard the summer weather report phrase “cooler near the lake.” Those who aren't a fan of the sweltering heat thank the lake for making downtown five degrees cooler than it is away from the lake.

And frankly, what good is the lake if we can't enjoy it on the beach? To the layman, Lake Michigan begets Chicago's beaches. Truth is the beaches are actually are man-made. In fact, some of the downtown area's land – Streeterville, for instance – is man-made; that area was once part of the lake. Not every city offers the opportunity to sunbathe adjacent to skyscrapers. And, thanks to the beaches we have the chance to enjoy some time lakeside to people watch, without blatantly gawking and staring at others.

Navy Pier's fireworks and the Air and Water Show are two of Chicago's best-known events, which incidentally, both take place on the lake. It's next to impossible to have and air and water show without the water, not to mention the fact that these summer festivals on the lake bring in millions of tourist dollars every year.

Aesthetically, Lake Michigan is very pleasing and offers may summertime activities. But the temperature is frigid even in summer, and there are many scary things lurking, quite literally, below the surface.

It seemed like every other day beaches were being closed last summer due to dangerous E. coli levels in the lake's water, a trend that has been rapidly increasing since 1994. 2003 alone saw a whopping 397 beach closings, an unbelievably disconcerting number, considering where E. coli comes from: pigeon droppings, garbage and human and animal waste. According the Lake Michigan Federation, the largest known source of bacterial pollution to the Illinois lakefront is the North Shore Channel. When opened, the channel dumps millions of gallons of untreated wastewater into Lake Michigan, upping pollution levels far beyond what state water quality laws allow. The channel, which runs through Chicago, Lincolnwood, Skokie and Evanston, is dumped into the lake when it can no longer handle waste overflows, a situation that can occur from heavy rains.

Strangely enough, it seems like the beaches are opened shortly after they are closed, implying that the water is clean and safe to swim in. By law, the levels are back down to acceptable numbers, but the bacteria still exists. Should you decide to swim in the lake the day after a closing, feel free. You're the one swimming in a quasi-sewer. You'll have no one else to blame for contracting gastroenteritis.

Water pollution affects more than those swimming in the lake and comes from more than sewage channels. Lake Michigan becomes polluted because of contaminated water coming from construction sites, city streets, and seeping landfills, all of which eventually drain into the lake. The Clean Air Act of 1972 helped clean the water up considerably, but the fact still remains that pollutants still seep into the lake from the aforementioned areas. Other factors out of one's control contribute to the lake's pollution such as acid rain, auto exhaust and factory and power plant emissions.

Pollution, E. coli and beach closings are not the only negatives the lake possesses. Some creatures not indigenous to the great lakes have found their way here in recent years, a situation biologists and lake experts found alarming. Consider the Northern Snakehead. There is something inherently wrong with this animal. Dubbed “Frankenfish” for its ability breathe out of water, travel short distances in search of other bodies of water and consume whatever happens to be in its path, this ravenous creature was found in Burnham Harbor in mid-October.

Originating in China, Korea and Russia, Frankenfish can grow up to three feet long and, once full grown, eat other full-size fish. Biologists were concerned because once introduced into a new environment, the voracious alien fish will devour anything and devastate entire freshwater ecosystems. In the case of Lake Michigan, it could destroy the freshwater salmon population, throwing the lake's ecosystem off.

Biologists conducted a search for other Frankenfish shortly after the first one was found, but fortunately came up empty. They theorize someone had Frankenfish as a pet and got tired of feeding it all the time and dumped it in the lake. It is, by the way, illegal to bring live Northern Snakeheads into the U.S.

If you happen to be outside and see a large fish slithering across land consuming all living things in its path, alert the authorities immediately and hide.

Zebra mussels are another Lake Michigan intruder. The good news is they are not quite as insatiable as Frankenfish. First discovered in the lake in the 1980s, Zebra mussels are nuisances because they procreate in mass quantities and stick to water intake pipes, clogging up the city's water supply. They too can have an effect on the lake's ecosystem because they filter the water that goes through their bodies, ridding the water of algae. This appears to be beneficial, but in fact changes the water's environment because more sunlight gets into the water due to the lack of algae, which ultimately negatively affects the ecosystem because the plants and animals are not accustomed to that much sunlight.