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Did you know that you are in a watershed right now? A watershed is any area from which water above and below ground drains to a specific stream, river, lake, bay, or ocean. All of the water that flows over or through a watershed ends up in the body of water it drains to, including whatever this water may pick up along its way.

Image of water moving through a watershed.
Watershed map .gif Repurposed from the Rockingham County, NC website

When it rains, all of the water drains to one body of water. It falls on land and travels to a stream and eventually a river that empties into a lake or ocean. Water also soaks into the ground to add to groundwater and underground rivers. This graphic shows the process of water entering the watershed.

Image of Montgomery County topography
Montgomery County's watersheds are determined by the geography, topography and water flow.


The watershed boundary is defined by the dividing line of highest elevation surrounding a given stream or network of streams. Rainwater falling outside the boundary will flow into an adjacent watershed and another receiving water body.

Watersheds can be small or large, and smaller watersheds can combine to make a much larger watershed. Montgomery County is in the larger Chesapeake Bay watershed which means all of the water that comes through, or is from here, goes to the Chesapeake Bay. We also have parts of the Potomac River watershed and the Patuxent River watershed located within our county. Our area is further divided into 8 major watersheds within Montgomery County.






Our Local Watersheds

Image of Lower Booze Creek in Montgomery County


No matter where you are, you are in a watershed.


A watershed is all the land and all the water that drains over or moves under that land to one point.

Watersheds can be very small, like the one for the stream that may flow through your backyard or the local park. These small streams join together to form larger and larger waterways with larger and larger drainage areas like the Chesapeake Bay and Mississippi River watersheds. 

Montgomery County has over 1,500 miles of streams in the county. Pretty impressive! Some of these streams and watersheds are healthy while others are not. DEP determines stream health by the organisms that live in those streams.


How the land and streams are cared for upstream has a significant impact not only to our local environment but to the ecosystem downstream as well. Remember, We all live downstream!

Want to know exactly which watershed you live in and its health or which watershed you are sitting in at this very moment? Use the Interactive watershed map below.


Find Your Watershed Map

View larger map



County Watersheds

Montgomery County is made up of eight major watersheds and almost 150 smaller watersheds. The map above shows streams, tributaries, lakes, and other water features within Montgomery County as well as their health and condition.

Click on any colored area to determine the most recent stream conditions of that area. If you’d like to determine your “watershed address”, simply type in a street address to see the watershed name and a short description.

All county watersheds are monitored according to a defined schedule at least once every five years. The types and health of fish species and stream bugs (also called benthic macroinvertebrates) provide a snapshot of the health of the watershed. Click the "View Larger Map" link below the map to view it in full screen.

If you’d like to learn more about our County watersheds view the list below. You will learn their location within the County, more about their biological condition and physical features and other interesting facts.


County Watersheds


Image of Department of Environmental Protection staff leading a restoration walk at Booze Creek.
 Department of Environmental Protection staff hold restoration walks to show County residents how DEP restores local streams.




Cabin John Creek


Lower Monocacy



Lower Potomac Direct



Image of northern red salamanders
Northern red salamanders are one of the many animal species that call Montgomery County watersheds home.

Patuxent River



Rock Creek



Seneca Creek



Upper Potomac Direct



How Do Watersheds Affect Us?

Healthy watersheds offer many valuable functions and are essential for appreciating the local natural environment. 

By protecting our watersheds and preventing pollution, we help secure our quality of life and reduce the costs of government cleanup programs. Also, keeping our local waters clean helps protect the water supply and habitat for people and animals that live downstream, allowing them to experience the same benefits.

In a healthy watershed, there are:

  • Recreational opportunities such as fishing, canoeing, or boating
Image of a yellow bullhead fish.
  • Habitats for wildlife and fish.  Good water quality is important for both fish and their food sources.
Image of a trout swimming in a Montgomery County stream.
  • Lower costs for drinking water. The dirtier the water, the more expensive the treatment before being piped to your home.
Image of the "Do Not Pollute! sign next to storm drains.
  • Aesthetically pleasing surroundings. Clean waterways offer beauty in the landscape.
Image of a beautiful stream.
  • Escape from urban development. Waterfronts are peaceful places that people can enjoy.
Image of the Northwest Gorge
  • Homes, businesses, and roads protected from flooding and other natural disasters.
Image of water pouring out of a stormdrain.
  • Less polluted waters creating better public health and safety. Polluted water can be a human health hazard.
Image of a tree covered in trash
  • Reduced tax burdens to clean up and protect the environment. 
Image of a stream with extreme erosion next to a house.