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Do you know where your water comes from?

Today’s post comes from ILACSD’s Marketing Intern, Brian McComb, and continues our theme from yesterday on how you can protect our local waterways.

As this summer has given us one of the worst droughts in recent US history, coupled with the ongoing plague of droughts in Africa and Eastern Europe, there is perhaps no better a time to focus on water!

So do you know where your water comes from? Chances are you are actually sipping on water that came from your local river or stream. In fact American Rivers – a leading organization working to protect and restore the nation’s rivers and streams – estimates that almost 65% of drinking water across the United States comes from rivers and streams. Unfortunately they also estimate that nearly 40% of all rivers and streams in the U.S. are too polluted for even fishing or swimming.

So what is a watershed? Well our rivers and streams are only the most visible part of a much larger system, a system that connects our land to our water in ways we don’t usually realize.  So as water becomes more and more important to our world’s ever-expanding population, the protection of watersheds becomes an ever more pressing matter.

Okay, so then what is a watershed? In essence, a watershed is the area of land where all the water (whether falling as rain or pumped out of the ground) eventually drains towards, meanders through, or somehow filters back to collect and replenish a common water source. It’s a swath of topography that contributes to a common water table, and it relies completely upon itself to sustain the water supply.

Watershed In Action

One of the important things to realize about watersheds, is that they include large areas of land around a visible water sources. Even if you are miles away from the nearest stream, what you do to the land in your area can still have a huge impact on the water. Chemicals dumped on desert rocks can seep through the ground and enter the same aquifer that feeds a far away stream. Garbage tossed into a seemingly dry gully can be swept away when a rare rainstorm turns that gully into short-lived class IV white water rapids. The point is, although trash and debris might be tossed far away from a water source and are no longer in your “backyard,” that debris may still end up contaminating your tap water.

Now not all watersheds are created equal. Some watersheds may feed into lakes, while others drain into a system of streams and rivers that eventually end up in the ocean. Some watersheds may cover little more than a hundred miles total (i.e. the San Diego watershed), while others (like the Mississippi watershed system) can span hundreds of thousands of miles.

Mississippi River Watershed

Watersheds come in all shapes and sizes across the world and are not limited by state or national boundaries. In the continental US alone there are over 2,100 watersheds. Though there are larger and smaller watersheds, no watershed is too large to be impervious to human harm.

Watersheds are extremely important to our daily lives as well as our future. To learn more about watersheds, check out resources like

Also, through I Love A Clean San Diego’s High School Watershed Education Program, we offer FREE watershed presentations to high schools within the City of San Diego and the unincorporated areas of the County of San Diego.

Our standards-based presentations focus on local watersheds and how pollution affects human health, as well as the health of local ecosystems. Help us keep our watersheds clean and healthy and empower students to be environmental stewards in their communities. These presentations are flexible to best fit your school’s schedule – schedule just a few classes or an entire day.

For more information or to schedule a presentation for your organization or club, please contact our Education Coordinator, Erika, at

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