The "What" and the "Why"
What is a watershed?
A watershed is an area of land that is linked by water: either underground, or above ground. This water drains into one location such as a lake, river, or wetland. The water usually comes from rain and from household and industrial wastewater. Most of the time, water from one area is directed to the lakes and/or rivers through drainage systems. This is where runoff and sewage usually end up.
The Anacostia Watershed is right in our backyard! It covers some of the DC and Maryland area and consists of 176-square-miles of land. It spans 3 counties, in which more than 600,000 people live. The Anacostia Watershed feeds into the Potomac River, which flows into the Chesapeake Bay.
What do we want to know?
We want monitor the health of streams in the Anacostia Watershed. To do this we are looking at a few things!
We can look at tiny bottom-dwelling creatures called macroinvertebrates. They don’t have back bones, are visible with the naked eye (unlike most plankton), and form the link between producers and higher consumers in the food web. In streams, the most common macroinvertebrates are larvae of insects like mayflies and dragonflies. Their presence or absence can indicate changes in the health of streams—some types of macroinvertebrates can survive even if the water quality is very low, while other types are more sensitive and can only be found in streams with really healthy streams.
Are watersheds interconnected?
Water in a watershed can come from anywhere in the surrounding area. This can be agricultural fields, the backyards of homeowners, and factories that do not treat their chemical sewage. If harmful water gets into the watershed, we cannot prevent it from spreading elsewhere. So, the environmental problems that impact the Anacostia Watershed aren’t problems just for the communities inside the watershed, but have negative consequences all of the communities that are downstream from the Anacostia Watershed. All of the streams and run-off from the land within the Anacostia Watershed feed into the Anacostia River, which flows into the Potomac River and eventually into Chesapeake Bay. Through fishing, crabbing, tourism, and other industries, the Chesapeake Bay supports hundreds of thousands of and residents and visitors throughout the region who use the Chesapeake Bay as a source of food and recreation. Too much pollution in the Anacostia, Potomac, or Chesapeake Bay can make these activities dangerous for people, and for the animals that depend on these ecosystems to survive. Watersheds are one of the ways that seemingly disconnected communities depend on one another. If a watershed further upstream is unhealthy, it will have an effect on the health of a watershed downstream.