What is the value of water?

Riparian buffers and wetlands act as natural land areas and protective  boundaries between land and water that  can capture, store, and filter pollutants and control erosion.  They also provide natural  habitats that contribute to a healthy environment.

Students will discover how natural areas between land and water play a significant role in water quality protection in our watershed. Recognized for their value, when they are in poor condition, environmental engineers have figured out ways to restore them to their healthy condition.

INTRODUCE TERM “RIPARIAN BUFFER”

Students may not know  Riparian Buffers by name, but may have experienced them in their local environment, particularly in our urban forested parks like  Pennypack, Cobbs  and Wissahickon.  A riparian buffer is a zone of vegetation located along the bank of a waterway that serves to protect the water from harmful runoff. The roots of plants and trees in the riparian buffer stabilize the soil and control erosion.  Without these plants, the soil can wash away, eroding the gentle streambank and causing faster and more volume of runoff in a rainstorm.  The plants and trees slow water flow, reducing the threat of erosion and downstream flooding after heavy precipitation. By slowing water flow, riparian buffers allow more water to naturally infiltrate the soil. Wetlands are also natural vegetated areas that capture and slow the flow, before infiltrating water into the ground (part of the natural water cycle!)  Both of these types of natural areas encourage  the recharging of groundwater, capturing and filtering pollutants as they infiltrate through the soil.

As a class view Slide 2 and define “riparian buffer” using the illustration and characteristics described in the poster.

Now show Slide 3 and have  a short discussion about the relationship between soil types and infiltration rates. This will help students get a better sense of the natural variables that contribute to the benefits of  buffers as natural stormwater management.

If you have time, share The Dirt on Soil to have a more in depth discussion.

View this video:

 Riparian video (20 minute video but the first 7 minutes are recommended or this other shorter Riparian Buffer video (a 3-minute video based on the Lower Chippewa River) .

EXPLAIN

Slide 5: This is a  movement activity that encourages all  students to act like a stream bank to demonstrate  the benefit of the  buffer area at the rivers’ edge.  It could be chaos, but it also could be fun!

Step 1: Make a stream

Arrange the classroom so that there is a cleared center aisle down the middle. This will represent your waterway. Make sure there is enough room on either side of the aisle (now your flowing waterway)  for two groups of students to become the streambank on either side of the aisle.

Step 2:  Make a riverbank 

Select some of the students to line up facing each other on either side of the aisle (now your flowing waterway) . They can stand side by side or link arms.

Step 3:  Land

The remaining group of students on either side of the classroom will now gather up some crumpled paper clean recyclables and something that might even simulate!  oil  or pesticides (You may want to get these supplies ready ahead of time and distribute at this point in the activity.) 

Step 4:  Activate your model!

You say– “It  is starting to rain or get very windy.”   Students with the objects start trying to get through the line of students along the stream, while the line of students along the stream hold them back (this is where the controlled chaos begins!)  They can roll their items on the floor , or try and squeeze them through the line

This part of the activity simulates stormwater carrying everything off the land  downhill by gravity to the line of students acting like a barrier along the stream .

Their  streambank students act as a buffer! Capturing  the objects and preventing them from getting into the aisle (the stream) or at least slowing them down .

Have students draw and label a diagram explaining how riparian buffers and wetlands benefit the health of a watershed.

Show some examples of how PWD is engineering streambank restoration by showing a few images  from these selected projects.

RESOURCES ABOUT RIPARIAN BUFFERS 

Encourage students to read articles about Riparian buffers. Some suggested articles are listed here:

Riparian Forest Buffers (Pennsylvania Department of Conservation and  Natural Resources)
Riparian Buffers for Wildlife (Penn State Extension)

Students will investigate how soils and vegetation affect how the water cycle interacts with the watershed.

Students may use this Riparian Model Observation Sheet  to assist with documenting their observations.

Choose one of the  demonstration models—the set up you choose may be determined by whether you have access to the Foss Landforms kit or the STC Land and Water kit. If you have access to either kit, use the stream table set up and you may choose to follow up with the paint tray demonstration. If you do not have access to a stream table, use the paint tray model.

If you have a stream table, use it for a class demonstration and then have students break into smaller groups using the paint trays, aluminum foil roasting pans or clear plastic sweater boxes

Stream tables can also be made from paint trays, aluminum foil roasting pans or from clear plastic sweater boxes. A drainage hole can be drilled or cut in the corner and covered with duct tape.

Stream tables can be filled with soil, sand, gravel and/or diatomaceous earth (if allowed) first as a demonstration.

The stream table model can be followed by a group activity using paint tray model , which does not require soil.  You can use  different types of sponges and/or some soil to model soils found under different types of vegetation.

Allow the students to explore the model themselves.

Encourage students to examine what happens in both models when the slope of the hill is varied; and how does vegetation protect those steep slopes?

Draw and label a model explaining how riparian buffers and wetlands benefit the health of a watershed.