Watershed Basics
The area of land where all water drains toward the same river, stream, lake, or other body of water.
What is a watershed?
In your watershed model, the crumpled pieces of paper represented this feature of the real landscape.
What are hills, valleys, and other changes in elevation?
This is a smaller flowing body of water that eventually joins a bigger body of water or river.
What is a stream?
In the stream-order system, the smallest streams that do not have any smaller streams flowing into them are called this.
What are first-order streams?
This is the place where a smaller stream flows into a larger stream or river.
What is a confluence?
In the watershed model, the plastic bag helped you see where the water traveled and collected. What did the plastic bag represent in the model?
What is the landscape or land surface?
This is the direction that water generally moves across a watershed.
What is downhill/downstream?
When two streams of the same order meet, the resulting stream increases by one order.
What is the stream-order rule?
Water falling as rain, snow, sleet, or hail is an example of this part of the water cycle.
What is precipitation?
After adding water to your model, you noticed that some areas stayed relatively dry while other areas collected more water. What could you conclude from this observation?
That water collects and flows differently depending on the shape and elevation of the landscape.
A river system can be compared to the veins or roots of a tree because both have this characteristic.
What is a branching network?
Two first-order streams meet. What stream order is created?
What is a second-order stream?
A watershed is defined by the movement of water. This force is primarily responsible for causing water to flow downhill through a watershed.
What is gravity?
Your model demonstrated that the shape of the land affects where water goes. What scientific term describes the study of Earth's surface shape and features?
What is topography?
A student is looking at a map and sees one large river with many smaller streams branching into it. Explain what this tells you about the landscape.
The smaller streams drain water from surrounding land into the larger river, creating a connected drainage network.
A second-order stream joins a first-order stream. What is the order of the resulting stream?
What is a second-order stream?
Two neighboring watersheds are separated by a higher area of land. This boundary determines which direction water will flow.
What is a watershed divide?
A small stream begins high in the landscape. As it travels downstream, three smaller streams join it. Explain why the stream generally becomes larger as it moves downstream.
The stream is receiving additional water from tributaries and the surrounding watershed, so the amount of water flowing through it generally increases downstream.
In your watershed model, you observed that water did not spread evenly across the entire landscape. Instead, its path depended on the shape and elevation of the land. Explain how this model demonstrates what determines the boundaries of a watershed.
A watershed's boundaries are determined by higher areas of land, called watershed divides. Water falling on different sides of a divide flows downhill into different drainage systems.
A student says, “Every time two streams meet, the stream order increases.” Explain why this is incorrect, and give an example.
Stream order only increases when two streams of the same order meet. For example, when a first-order stream joins a second-order stream, the resulting stream remains second order.
The West River flows through Connecticut before eventually reaching Long Island Sound. Imagine that rain falls on two nearby locations—one on each side of a watershed divide. Explain why the water from these two locations could end up in different streams or rivers, even though the locations are close together.
What is the watershed divide directs water on different sides into different drainage systems? The shape and elevation of the land determine which direction the water flows, so nearby areas can belong to different watersheds.