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Learn about human impacts on river health and ways to restore rivers to a healthy state. Discover problems like river straightening, dam construction, and pollutants, along with solutions such as allowing rivers to migrate, dam removal, and implementing water treatment practices. Explore benefits like improved habitat for fish, cleaner water, and healthier ecosystems. Engage in a review project to create posters showcasing negative impacts, restoration efforts, and the benefits of river restoration. Consider alternative review ideas such as inviting a river restoration practitioner to speak to the class or organizing a Skype session with a geomorphologist.
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Healthy Rivers & River Restoration Learning Target: I can describe some ways that humans have altered rivers and what can be done to restore them to a healthy state. • Micah Nelson
What does a healthy river look like? Talk to your shoulder partner: What you think a healthy river might look like. What would you see in and around a healthy river? After a minute, draw a picture of what you think a healthy river should look like.
Healthy River Definition: A healthy river is a river that can support a variety of healthy plants, animals and humans.
Humans have done damage to river health in many ways. Can you describe some of the ways that the rivers below are unhealthy? Wayne McLean
River Restoration is the effort to return rivers to a healthy state in which they support diverse ecosystems with plants, animals, and humans. In the following slides you will learn about problems, solutions, and the benefits of river restoration. • Micah Nelson
Problem #1: Straightening Rivers Sometimes people change a river channel from a winding path to a straight path. What could be wrong with this?
Restoration Solution: Allow Rivers to Migrate River channels naturally migrate or move across their floodplain over time. Note the patchy, diverse floodplain of this river, which likely supports a variety of plants and animals. South Florida Water Management District
Restoration Benefits: • When this rivers migrate and flood, they send nutrients onto floodplain forests that create habitat for fish and fertilize the plants. Micah Nelson
Problem #2: Dam Construction Dams block the flow of water downstream, preventing the benefits of floods on the floodplain. Dams create reservoirs upstream, permanently covering what used to be a river valley
Restoration Solution: Dam Removal This dam on the Elwha river in Washington State (left) was removed, and salmon are now migrating back up the river to their original spawning grounds (right).
Historic salmon spawning grounds Salmon spawning grounds after dam construction Restoration Benefits: The Elwha river was dammed in the early 1900s, preventing salmon from migrating to their spawning grounds, severely decreasing their population
Problem #3: Pollutants from Cities and Farming • Water that falls as rain or snow runs off the land and over cities and farms before making its way to a river • On the way to the river, water can pick up toxic pollutants, or even normally non-toxic things like nutrients that become toxic at high enough concentrations
Problem #3: Pollutants from Cities and Farming • Rivers reflect the landscapes around them • Restoring rivers means fixing problems all over the landscape
Restoration Solution: Water Treatment and Changing Land Use Practices • No-till farming helps prevent excess sediment in rivers • Retention ponds in urban regions can enable water treatment • Stormwater management in cities can be designed to filter and treat water being delivered to streams Corey Coyle
Restoration Benefits: • Cleaner water being delivered to streams makes for cleaner and healthier streams. • Healthy rivers support healthy plants and animals.
Review Project • Get into a team of 2-3 students. • Have students create a poster or series of posters with three slides. • One slide should describe a way that humans have negatively affected a river. • The second slide should describe or depict an effort to restore the river to a healthier state. • The third slide should describe why the restoration is beneficial for the river.
Alternative Review Ideas • Contact a river restoration practitioner (or a county or city land manager who works on rivers) and ask them to speak to the class about what they do. • Do a skype-a-scientist with a geomorphologist or river restoration practitioner (https://www.skypeascientist.com/)