by Elena Takaki
Not everyone lives next to a stream or river but we all live in a watershed. A watershed is an area of land from which rain and melting snow drain into a river, stream or other body of water. The Chesapeake Bay Watershed is the land area drained by all the rivers and streams that flow into the Bay. Home to 14 million people, it covers 64,000 square miles and includes parts of six states and the District of Columbia.
The Bay's watershed is made up of thousands of smaller watersheds that drain into its tributaries. For instance, the Monocacy River Watershed is part of the larger Potomac River Watershed, which, in turn, is part of the Chesapeake Bay Watershed. Whether you live right on the water - or, like most Marylanders, within a half-mile of your neighborhood stream - your actions on the land can impact water quality in the streams and rivers that feed the Chesapeake. And the health of the streams and rivers that flow through your neighborhood directly affect the health of the Bay.
Here in Maryland, state agencies and organizations are reducing the amount of nutrients that enter our waterways. These nutrients find their way into our streams and rivers from widely scattered sources on the land. Excess fertilizers from farm fields and suburban lawns, sewage from old septic systems, and sediment from construction projects all can wash off the land every time it rains. Even pollution from our own backyards and driveways can find its way into our waterways through the network of storm drains that empty into neighborhood streams and rivers. Therefore, the way we manage growth in our towns and cities, care for our lawns, run our households, and grow our food can all affect water quality.
Watersheds also include all the water that soaks into the ground and becomes part of the groundwater system. Groundwater moves between rocks and soil particles underground - just like water fills a sponge. It can empty into a lake, stream or the Bay, bringing with it contaminants such as fertilizers, pesticides and other dangerous materials.
There are a lot of things we all can do to keep our watersheds healthy: use fewer hazardous materials, plant trees next to streams, carpool, and recycle to name just a few. But the best thing we can do is monitor them. Since everything we do on land affects the water, we can measure the quality of the water and then determine if we need to change our land use practices.
Perhaps you notice a lot of dirt in a stream after a rainfall. You know that all that dirt can cause many problems like covering up salamander eggs, clogging fish gills and increasing water temperature. Wondering where it came from, you look around to see that the stream banks are severely eroded and all that dirt, or sediment, is emptying into the water. One thing you can do to stop that erosion is to plant trees and shrubs along the edge of the river - the roots will help keep the remaining soil in place.
Scientists are continually measuring the water quality of the Chesapeake Bay Watershed. They test the streams and rivers as well as the Bay itself, and then they make recommendations on what we can do on land to improve it. Their recommendations have led to construction sites using sediment fences to keep dirt from running into rivers, homeowners using fewer pesticides and fertilizers on their lawns, and citizen groups organizing stream cleanups and tree planting projects.
Just remember: No matter where you are, anywhere in the world, you live in a watershed. We all have a responsibility to make sure ours stays healthy and remains a great place to live!
Elena Takaki is the Program Manager of DNR's Watershed Stewardship unit.
To help improve the Chesapeake Bay Watershed, you can join Maryland's Tributary Strategy Teams. They help implement pollution prevention measures needed to address local water quality problems. For more information, visit http://www.dnr.maryland.gov/bay/tribstrat
If you want to explore a watershed, all you have to do is walk out your door. To find out more about watersheds in Maryland, visit the Bay Links website at http://www.dnr.maryland.gov/baylinks/index.html. Or for general information about watersheds, visit the Environmental Protection Agency's website at http://www.epa.gov/owow/watershed/.
We're on the Map!
By defining the boundary of a watershed, we can determine what type of pollution affects a body of water and where that pollution comes from. Once we know that, we can figure out how to clean it up! The slope of the land determines the boundary of a watershed. Use the map on the following page to draw the watershed boundary of the Bread and Cheese Branch stream.
- Start at Youths Benefit School.
- Draw a continuous line around Bread and Cheese Branch. Hints:
- Your line should weave between the maze of rivers and streams but only cross the Bread and Cheese Branch where it starts.
- Locate churches, schools and large buildings on the map. Many important buildings are built on hilltops.
- Looks for small circles. These are hills, which will indicate watershed boundaries.
- Watershed boundaries usually follow the "in between" rule: whenever you find two different streams, the watershed boundary may be in between the two streams.
The graphics for this activity can be found at http://www.dnr.state.md.us/education/are/big/big_watershed.pdf - you will need page 5 and 7 of the PDF document (or 10, 11 and 13 as it is labeled on the student sheet).
Reprinted by permission of the Maryland Department of Natural Resources.