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Elementary Ecosystem Investigation: Rain Garden

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Forest Hills Elementary Rain Garden
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Investigate Rain Gardens
and Wetlands

A rain garden is created to help slow down stormwater runoff. This garden is planted with native plants and serves the same functions as a natural wetland – water filtration and storage, flood and erosion control, and habitat for wildlife.

Click on the topics below to learn more!
What is a Rain Garden? What is a Wetland? Importance of Wetlands Wetland Conservation


What is a rain garden?
What is a rain garden?

A rain garden is a garden that contains native (naturally occur in an area) plant species planted in a dip in the ground, typically on a natural slope.

These gardens are dry most of the time and only hold water after rainfall.

Purposes of a rain garden:

  • Filter and store water
  • Habitat for wildlife
  • Flood and erosion (destruction of soil over time) control
  • Absorbs and soaks up stormwater runoff that flows from buildings, rooftops, roads, parking lots, sidewalks, and lawns
How a rain garden works
Clemson Cooperative Extension System
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What is Runoff?
As rainwater flows along water-resistant surfaces, it collects pollutants like dirt, fertilizer, chemicals, oil, garbage, and bacteria.
If the flow of the polluted runoff is not stopped by a rain garden, it will go directly into nearby streams and ponds, causing them to become polluted.

Without rain gardens, the increased flow into streams and ponds can cause them to become flooded which can lead to damaged homes, injuries, and potential deaths.

Runoff
flickr – Mississippi Watershed Management Organization
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Effect of rain gardens:

Rain gardens can remove most of the nutrients and chemicals from runoff and absorb more water than a normal lawn.

The soil in the garden slowly absorbs the water, eventually reaching and refilling aquifers (underground layer of rock that holds water).

As the water is absorbed, it is filtered by the plants in the garden.


What is a wetland?
A wetland is an area of land that is covered by water either seasonally or permanently.

They typically occur where water gathers or pools at a faster rate than it drains or evaporates.

Why is it wet?

  • The water is usually groundwater that seeps up from an aquifer (underground layer of rock that holds water) or spring (where water frows from an aquifer to Earth's surface).
  • It can also come from nearby lakes or rivers.
  • In coastal areas with strong tides, seawater can create wetlands.
Natural Spring
Gaius Cornelius – Wikimedia
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An important characteristic of a wetland is its vegetation which has adapted to wet (hydric) soil. These plants are called hydrophytes.
Types of wetlands:
Swamps:
  • wooded, dominated by shrubs and trees
Marshes:
  • dominated by grasses

Bogs:
  • soft, spongy grounds made of decayed plant matter (peat)
Swamp
Yinan Chen – Wikimedia
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Marsh
Dreamstime – Soph
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Bog
Kenneth Allen
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Other types of wetlands include seeps, springs, and ponds. Large wetlands can also be made of several types of smaller wetlands.


Importance of Wetlands
Flood Control:

During periods of heavy rainfall or snowmelt, wetlands absorb and slow the flow of waters.

This limits the effects of flooding, preventing the waterlogging of crops and potentially saving lives.

Filtering Pollutants:

Plants, fungi, and algae in wetlands filter and absorb extra pollutants and particles. This protects rivers, lakes, and other bodies of water.

Pavement and buildings tend to increase runoff, and farms tend to produce a lot of pollutants. Because of this, wetlands within and downstream of cities and farms are particularly important.

Erosion Control:

Slowing and storing water also reduces erosion (the
wearing away of land) and the damage it causes.
Benefits of Wetlands
Earth Gauge
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Erosion Damage
flickr – U.S. Fish and Wildlife Service Headquarter's photostream
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Economy:

Wetlands are popular places for hunting, hiking, canoeing, bird-watching, and other
outdoor recreational activities.

The U.S. Fish and Wildlife Service states that Americans spend more than 100 billion dollars on wetland-related activities every year.

Children in kayaking in wetland
Pixabay
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Provide Habitat:

Wetlands are one of the most important habitat types on earth. They provide food, water, and shelter for adult and baby animals of all kinds.

Birds use wetlands for feeding, breeding, and as a place to rest and refuel during migrations.

Dead plant material breaks down in the water and forms tiny pieces of organic material. This material feeds small aquatic insects and fish that are food for larger fish, reptiles, amphibians, birds, and mammals.

Local and Migratory Birds Using Wetland (India)
Shariqkhan – Dreamstime
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Animals that benefit from wetlands:

Wetlands serve as nurseries for amphibians and dragonflies as well as fish and crabs.

These animals spend the beginning of their lives in the shallow waters of wetlands before venturing out onto land or deeper waters.

To read more about the life cycle of frogs and the importance of water to it, CLICK HERE.

Upland Chorus Frog
Dreamstime
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Wetland Conservation
Wetlands have spongy, wet soil, so they can be quite difficult to build on. They have been thought of as useless for most of history.
Draining wetlands to create usable land for housing, school, hospitals and shopping centers was common for a very long time.

The capitol of the United States, Washington D.C., is built on a large, drained wetland.

Almost half of the wetlands in our country have been destroyed for development.
U.S. Capitol Building in Washington D.C.
Tomasz Szymanskia – Dreamstime
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In the early 1970’s, our government began to see the value in wetlands and developed laws

protecting them and the living things that called them home.
They have also started recreating them in areas where they have been destroyed.


SOURCES