Concept: Watersheds, Wetlands 1 Discovery Communications, LLC and Estuaries

Misconception 1: All rivers flow south.

No, rivers do not always flow south. Some rivers flow north, others east, others south, and so on. Rivers do, however, always flow from areas of high elevation to areas of lower elevation.

Getting to Know: Watersheds, Wetlands, and Estuaries Water is all around us. The water cycle moves water throughout the planet; you probably already know many details about the water cycle such as how water evaporates, condenses, and falls as precipitation. When water falls to Earth, it interacts with various landforms on Earth, creating different types of bodies of water throughout the land. In this lesson, you will explore a few of these bodies of water and examine why they are so important.

What are some of the different water features we can find on Earth? Water appears in many different forms on our planet. You are undoubtedly already familiar with some of them, like rivers, lakes, ponds, oceans, and glaciers. This lesson will explore three other water features: watersheds, wetlands, and estuaries.

The term watershed actually denotes the region of land that drains water into a common body of water. For example, rivers start at places of high elevation and flow to lower elevations. Rivers empty into other bodies of water such as other rivers, lakes, or the ocean. All of the land area that feeds water into that river is part of the same watershed. Watersheds are divided by areas of high elevation or ridgelines.

A wetland is an area of land whose soil is saturated with water. Wetlands are often low-lying and are usually adjacent to another body of water, like a shoreline or estuary.

Estuaries are the places where freshwater mixes with saltwater—where a river meets the ocean, for example. Estuaries are found at the mouths of rivers. The water there can have a range of salinity, from freshwater to salty water to anywhere in between. The type of water in estuaries is often called brackish, a mix of salt and freshwater.

I am pretty sure I have been in a watershed before. Of course you have. That is because everyone, everywhere in the world, lives in a watershed! All land can be divided into watersheds. Knowing which watershed you live in helps you appreciate how your actions, and the actions of the people and industries in your

Wetlands are low-lying areas whose soil is saturated with water.

Concept: Watersheds, Wetlands 2 Discovery Communications, LLC and Estuaries

area, can impact the water around you. Do you know which watershed you live in? If not, you will learn about it in this lesson.

Keep in mind when you study watersheds that a watershed can have many different water features. Most watersheds will have a river system. A river system is a river plus all of the smaller rivers, streams, or creeks that feed into that river.

Why are wetlands and estuaries important? Wetlands and estuaries are both important habitats for many different plant and animal species. This biological diversity means that wetlands and estuaries are usually very healthy ecosystems. Estuaries in particular are very important for the fishing industry. Aside from the abundant life, wetlands and estuaries are also very valuable in terms of water quality. They help filter out pollutants and keep water clean.

Can humans affect the water quality in a watershed? Yes, humans can have a great impact on the land, water, and ecosystems present in a watershed. Human activities can have broad-reaching impacts on natural systems. For example, a factory in one area of a watershed might discharge waste into a river, which is then carried downstream by the current. This waste could end up affecting the entire watershed. It is important to be aware of the different ways humans can impact water quality in a watershed.

Misconception 2: A swamp is just a useless piece of land.

That is not true; swamps are not useless pieces of land. Swamps, and other wet areas like marshes, bogs, and wetlands, are very important. They help maintain water quality by filtering out sediment and pollution. They are also very important ecosystems and provide habitats for many different kinds of plants and animals. These areas can also protect other areas of land by absorbing the impact of storms and flooding.

Pollution in one part of the watershed can affect the entire

watershed.

Misconception 3: Rivers, lakes, and wetlands are all separate bodies of water and independent of one another.

No, all of the features of a landscape are connected. Rivers, lakes, wetlands, and bodies of water are all connected to each other. All of these water features are part of a watershed, and they are all interconnected (even if the water does not actually flow from one feature to another).