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Teacher Guide – Middle School Education @ Adelaide Botanic Garden

Water and Air are our most valuable asset, not gold and diamonds. It is the essence of life on earth. Searching for life on other planets physicists look for evidence of water as an indicator. Clean water is probably responsible for the improvement of health in society over the last 100 years as much as modern medicine. It cleans, refreshes our environment and plays a part in the beauty of nature. We need to value and protect it. This walk will show how the Adelaide Botanic Garden, the State and the federal governments are trying to do just that. South Australia is one of the driest places on earth and Adelaide is a growing city in that environment.

Key trail learning outcome: The First Creek wetland in the Botanic Gardens is one solution to the problem of water shortage. It captures stormwater, uses mainly plants to clean it and then stores it underground for later use in the Garden. It is an example of how we can copy nature to ensure we have clean water.

Wetlands Discovery TrailAdelaide Botanic Garden

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Booklet Content

• Bookings • Acknowledgements • Purpose and Key ideas • Australian Curriculum Connections • How to use this guide • Guidelines for groups in the Gardens • Before you Visit • How Does the First Creek Wetland Work? • Station information • Map • Resources

Bookings: All visits to the Botanic Gardens should be booked for risk management. Self-Managed Excursions Booking online: http://www.botanic.sa.edu.au/index.php/book-online Booking by email: dehbgschools@sa.gov.au booking form here Booking by phone: 08 8222 9311 Booking by fax: 08 8222 9399 Education Manager, discussions and assistance ph: 08 8222 9344 or email: Michael.yeo2@sa.gov.au Stay up to date with what's happening by subscribing to our e-info newsletter. Subscribe online at www.botanic.sa.edu.au

Contributions to this Trail:

Content: Steve Meredith, Michael Yeo: Design Tom Chadlek

© 2015 The State of South Australia, Department for Education and Child Development and the Botanic Gardens of South Australia. This publication is protected by copyright. It may be reproduced by South Australian teachers for use with their students.

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Purpose and Key ideas of the trail:

Target year levels: Middle years

Key ideas:

• The importance of water and the need to manage it well. • Wetlands are important environmental assets.

Students will investigate:

• Water harvesting, filtering and storage processes. • Wetlands as a habitat, ecosystem and biome

Students are encouraged to observe, analyse, inquire, record, hypothesize and connect knowledge they already have with new learnings.

The wetland as a learning resource

A visit to the First Creek Wetland in the Adelaide Botanic Garden provides students with a unique first-hand experience of this increasingly important habitat type. The wetland is designed to be an educational space, specifically developed to assist students and the wider community with learning how wetlands can be used to filter and recycle water while at the same time improve the natural urban environment. Interpretive installations and viewing areas, including underwater views, support student learning throughout the wetland.

The wetland also forms an important part of the Garden’s water security plan. In five to eight years, the First Creek Wetland is expected to be able to recover up to 100 megalitres of water a year from the underground aquifer it is recharging. This is enough to irrigate the entire Adelaide Botanic Garden. It is an example of taking positive action to ensure that we have clean water in the future.

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Australian Curriculum Connections

This excursion links directly to different year levels and content in the Australian Curriculum.

General capabilities

• Literacy (students have the opportunity to record, discuss, use creative writing and reading analytic writing)

• Numeracy (various stations have numeric opportunities to calculate and interpret numeric values as part of the program and also extension)

• Critical and creative thinking

Cross-curriculum priorities • Sustainability

Geography Geographical Knowledge and Understanding

Year 10 Unit 1: Environmental change and management

Option: Environment Context: Inland Water

Year 9 Unit 1: Biomes

Year 8 Unit 1: Landforms and landscapes

Year 7 Unit 1: Water in the world

Science Science Understanding: Content Descriptions - Biological sciences

Year 4 (ACSSU072) & (ACSSU073) • Living things have life cycles • Living things, including plants and animals, depend on each other and the environment Year 5 (ACSSU043) • Living things have structural features and adaptations that help them to survive Year 6 (ACSSU094) • The growth and survival of living things are affected by the physical environment Year 7 (ACSSU111), (ACSSU112), • There are differences within and between groups of organisms; classification helps organise this diversity • Interactions between organisms can be described as food chains and food webs • Some of Earth’s resources are renewable, but others are non-renewable (ACSSU116) • Water is an important resource that cycles through the environment (ACSSU222) Year 9 Ecosystems (ACSSU176)

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How to use this guide

The Wetlands Discovery Trail self-managed education pack consists of a student guide and a separate teacher guide.

Using the Student Guide

The student guide is designed to encourage students to look closely at different parts of the wetland and respond to questions that encourage them to observe, record, think and problem solve as they walk their way around the trail. Minimal explanation assists them to interpret the space for themselves.

Using the Teacher Guide

The teacher guide provides possible responses to questions found at each station in the student guide. The responses are not exhaustive and can be expanded upon or amplified by teachers. Station information in the student guide is displayed in the teacher guide in coloured text. Certain stations have suggestions for simple demonstrations which can be conducted in class or during the visit. The trail takes approximately 1.5 hours to complete.

When in the Garden

In the garden students must be supervised at all times. Before starting your walk please remind your group that:

• Gardens are peaceful places for people to relax and enjoy. • Walking slowly and talking quietly ensures everybody and everything will enjoy the

gardens. • Plants are fragile, touch them gently. • Flowers, leaves, bark, seeds etc. growing on plants or lying on the ground are there

for all to enjoy. When you have finished with plant material found on the ground always return it to the garden.

• Keeping to paths and not walking on beds or borders avoids damage to plants. Risk Management

This walk with students is near water and requires close supervision by teachers and supervising adults. Please note:

• This walk is best done in small groups with direct adult supervision. • Appropriate student access to the pond edges must always be supervised by an

adult. • Sun protection is required, insect repellent at certain times of the year is

recommended. • After working in the wetland hands should be thoroughly washed particularly

before eating. Toilets can be found nearby at the end of the tram barn.

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Before you visit

Vocab: Before you visit students will benefit from an understanding the following terms:

Science Geography

Habitat Aquifer

Classification catchmentAdaptation Water cycle

Macrophytes RiparianMacro-invertebrates Biodiversity

Apex species ErosionPollutants Endemic

In small groups students might research and record ideas based on the following questions: (Some possible explanations included)

What is a catchment? A catchment is an area where water is collected by the natural landscape. Imagine cupping your hand in a downpour of rain & catching water. Your hands have become a catchment.

What is stormwater? Stormwater is rainwater that runs from roofs, roads, other hard surfaces and parks into stormwater drains. It then flows into creeks, wetlands and the sea. Stormwater can be captured, treated and used for non-drinking purposes.

What is the water cycle? Water is always cycling around, through and above the Earth. This is called the natural water cycle – the continuous movement of water between the land, ocean, rivers and creeks and atmosphere.

What is a wetland? Wetlands are natural or artificial areas where water collects and covers the soil all year or just a part of the year. They can form in many different ways and can have names like swamp, marsh, billabong and lake.

Why do we need wetlands? Wetlands can slow down floods, clean and store water, provide homes for plants and animals and provide places for us to enjoy the natural world.

What benefits could the wetland have over the long term? Besides recycling clean water and providing habitat for living things, the wetland might help educate people about the importance of water and biodiversity.

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Teacher’s station information

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This information provides pictures to help locate positions, possible answers to student activities and additional information for teachers to stimulate discussion.

Teacher notes in - Black

Student information in - Brown

Possible student responses – Purple

1. Location: Bridge near National Wine Centre (student book page 3)

On the bridge orientate students to the upstream and downstream sections of the creek.

(a) Water that enters this wetland starts in the Adelaide foothills, travels through Waterfall Gully and eastern suburbs then enters the Botanic Garden near where you are standing. Where else might the water come from?

Stormwater also enters the creek as it flows through the eastern suburbs of Adelaide. Run-off from hard surfaces entering street gutters and drains.

(b) What problem might this cause for the wetland?

Stormwater from roofs and roads may contain dirt, chemical pollutants, nutrients and a wide variety of litter or debris. The cleaner the stormwater the easier and cheaper it is to recycle it. Pollutants from stormwater could quickly fill up the wetland with rubbish and over time introduce chemicals toxic to both plants and animals.

(c) Look upstream towards the Wine Centre walkway. How do you know that this is now an artificial waterway and not a natural creek?

The concrete sides and rock baffling downstream indicate this is no longer a natural waterway but rather an artificial one.

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(d) How do the changes to the natural creek affect the flow of water?

The steep sided concrete channel reduces the width of the creek causing water to travel faster possibility increasing erosion. They are also smoother and with less obstructions that allows the water to move faster.

Students draw sketch of what they think the original creek would have looked like. It could include gently sloping banks with reed type plants in the water’s edge and shrubs and trees further up the banks. Many creeks in Adelaide were lined with River Red Gums, there are two opposite the Wine Centre.

(e) Sketch how the creek bed might have looked over 200 years ago, before Europeans arrived.

Students sketch.

Look downstream near the bridge. Find the trash racks.

(a) Explain how they work

Different sized debris and litter in stormwater gets trapped in the trash rack nets.

(b) What material would get through the racks?

Particles larger than the gaps in the net get caught, some smaller particles may get through.

(c) Explain the benefit of trash racks, not just nearby but much further downstream.

This is a good opportunity to introduce where the rubbish ends up and what the impact is. The creek runs into the Torrens near the Zoo then heads down to Henley Beach and runs out into the Gulf. The impact on sea grasses in the gulf has been significant. The sea grasses provide a nursery environment for sea creatures to breed and hide from larger predators. When removed they disappear reducing the food for the higher species etc etc.

Trash racks reduce the physical pollution of the creek leaving cleaner water to flow into the Garden and ultimately through Adelaide and down to the sea.

(d) Why were the trash racks positioned at this point in the garden?

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Trash racks were positioned here to improve the quality of water flowing through the whole Garden.

(e) What has to be done regularly to keep them working properly?

Trash racks have to be regularly cleaned of the rubbish to function most effectively.

Demonstration: Use different size strainers to filter a handful of fine to coarse objects eg sandy soil.

(g) Look further downstream. Comment on the natural and artificial nature of the creek in this section.

The creek has an artificial rock lining. It is more artificial than a natural creek bed because it consists only of large rocks and lacks layers of mud, vegetation and dirt banks.

(h) What do the big rocks do?

The large rocks slow the water flow as it enters the Garden.

This is a good time to talk about the structure of rivers. Past the wetland the creek meanders significantly and there are very obvious sections of erosion. Further opposite the Zoo the creek drops into a very deep V shape just prior to entering the Torrens River.

(i) Is there a more natural way of doing this?

The creek has a number of tight bends in the Garden, in this situation fast flowing water will quickly erode banks. The creek could be slowed by a series of rock baffles crossing the creek rather than a continuous line of rocks

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2. Location: Wetland water intake. (Student book page 5)

Look on the vineyard (southern) side of the creek walk upstream and find where water is diverted from First Creek into the wetlands. Keep away from the edge of the creek.

DANGER: There is a steep drop off near the concrete edge of the creek wall, please supervise students carefully at this point.

(a) Explain how the water gets diverted.

A cage covering an inlet pipe diverts water from the creek into the wetland. When water in the creek reaches a certain height some of it is forced into the wetland inlet pipe.

(b) Why is there a cage here?

The cage over the inlet pipe prevents larger debris getting into the wetlands.

(c) Is the shape of the cage important? Explain.

The angled shape of the cage deflects the creek flow washing away larger debris likely to block the cage, the water then swirls and comes in the back.

(d) Suggest reasons why only some of the water from the creek is diverted into the wetland.

The wetland is not big enough to process or clean the large amounts of water flowing down the creek when it is in flood. Only a proportion of creek flow can be dealt with at any point in time.

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3. Location: Gross pollutant or Sediment Trap (student book page 5)

Water travels underground from first creek to the gross pollutant trap buried under your feet. Look at the diagram on the steel plate that explains how it works.

(a) Point in the directions that the water enters and leaves the trap. Does all the class agree?

Water enters the trap from the Wine Centre then leaves through a pipe straight into the settling pond.

(b) Explain in your own words to someone else in the group how the trap works. Does your partner agree?

Water and floating litter is spun to the sides of spinning screen. Water is thrown to the outside of the screen through the fine mesh while litter is trapped by the mesh and eventually drops to the bottom. The filtered water is sent off to the settling pond.

(c) Is the trap designed to catch small or large particles before they reach the wetland? Explain.

The trap captures smaller particles. If the smaller size litter was allowed through it would quickly fill up the settling pond and slow down the water cleaning process.

Demonstration: Poor a jug containing coarsely chopped vegetables and water into a salad spinner. Spin it, talk about how it works in a similar way to the gross pollutant trap.

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4. Location Wetland - Settling Pond (student book page 6) Look over the railing at the first of THREE major ponds that make up the wetland. This is the settling pond.

(a) Is the water still or fast flowing here? Water is relatively still in the settling pond.

(b) How do the high banks help? The high banks reduce water movement by protecting it from the wind. Sediment settles out of still water.

(c) What happens to the sediment after it has been still for a while?

Over time the pond will fill up with sediment and will need to be cleaned out.

(c) Over time, what problem might this cause? Wildlife around this pond includes different types of water birds like ducks and ibis. The bird poo increases the nitrogen level and may cause algae.

(d) Would the water be clean enough for safe use (drinking) after leaving the pond? Why?

No, the water would not be safe for reuse at this stage as it still contains chemical pollutants like detergents, oils and fertilizers. The water may also contain harmful micro-organisms like bacteria.

Demonstration: Swirl dirty water in a clear glass jar. Wait and observe sediment settling on the bottom.

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5. Location: Wetland Crossing - Filter Pond (student book page 6)

Students will need to be managed well through this section. In particular it is important to spread them out so that they do not bunch up and push people in front of them or lose sight of their feet.

On the trash rack side of the pond walk next to the wetlands until you see to the rock crossing.

DO NOT go across until directed to do so by your supervisors.

Water flows from the settling pond to this filter pond. This crossing and another mounded bank further down divide the pond into three sections.

(a) List the differences you can see between the filter pond and the sediment pond.

Differences between this pond and the settling pond are:

• Water flows slowly through the filter pond, it is relatively still in settling pond

• Water is shallower and more spread out at this end of the filter pond

• Plants cover a far greater area in the filter pond.

(b) Count how many different types of plant you can see in the pond.

The numbers of plant types in the filter pond will vary but there are many different types.

This is a good opportunity to discuss the biodiversity of life in a wetland and hence their importance. (The importance of Biodiversity too)

(c) Do many of the plants have common features? If so what are they?

Many plants here have numerous, narrow, spear-like stems that grow from a clumping base. Plants also vary in the length of stems, growth shape, colour and flower heads especially those on the drier edge of the filter pond.

A good opportunity to inquire about adaptation.

(d) Many of the plants here might be grouped as: trees, herbs, bushes, reeds or vines

Many of the plants here are known as reeds.

An opportunity to introduce classification.

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6. Location: Reeds – Filter Pond (student book page 7)

DANGER: If it is safe to do so walk carefully with your supervisors to the reed sculpture in the middle of the pond. You are now in the middle of the working heart of the wetland surrounded by mainly reed-like plants.

(a) What problems might be faced by wetland plants living here? Problems faced by plants living here include saturated soils with little oxygen, strong competition from other aggressive plant types, changing water availability and flow rates, changing water quality and drying out in summer.

(b) Look closely at nearby reeds and soil. Why are the following features important for living in wetlands? Tall narrow stems. Tall, narrow stems assist plants in reaching light and growing above a changing water level.

(c) Why are the flowers high up on the plant? Flowers high up on the plant are more likely to release their pollen in the wind or attract insect pollinators.

(d) On the base of the plant, why do the plants have horizontal underground stems (rhizomes) or clumping roots? Horizontal underground stems (rhizomes) or clumping roots helps prevent uprooting caused by fast flowing water.

When water trickles through the reeds something living on them helps to takes out the nutrients and pollutants from the water.

(e) As a class group look at the metal sign nearest to you to identify which of the following is the water cleaner. An animal/ an insect/ a bacteria/ a plant.

Microscopic life in the form of algae and bacteria growing on the roots and stems of reeds help to clean the water by taking out pollutants and nutrients. This ultra-thin layer of life is sometimes called ‘biofilm’. Plants absorb nutrients.

(f) Reeds slow down / speed up the flow of water through wetlands.

(g) How does slowing down the speed of water help clean the water? Slowing down the flow increases the time plants have to filter the water.

Demonstration: Add food dye to water, place a stick of celery with leaves left on in it in the dyed water. Leave overnight and observe. Talk about how plants absorb water and dissolved nutrients.

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7. Wetlands Lookout – Pumps and Storage (student book page 8)

Continue on to the lookout on the other side of the pond. You can clearly see from here the 3 separate parts of the filter pond separated by rock causeways.

Water is pumped from the deep end of the filter pond to be stored underground. When water is needed for re-use, a different pump draws the water up from underground into the storage pond. From there it is pumped into the garden.

The explanation sign will help students answer the following:

The diagram on the on the lookout gives a good idea of how the water flows through the system. Your class might like to take some rubbings of the diagram, or take a picture.

(a) Water taken from the filter pond goes through mechanical filtration including ultra violet like before it is pumped underground. Why do you think this is the case?

This ensures it meets strict environmental protection standards and does not pollute the underground water supply and the aquifer.

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8. Plant ponds – Water Loving Plants (student book page 8)

Many of the plants in these small tanks are extremely rare endemic species. Some are nationally listed as threatened with extinction. This may be a good discussion point.

Walk down past the trickling waterfall to the plant ponds. Water plants have many different features to help them survive in water of different quality. Stop and enjoy looking at and learning about just a small fraction of the world’s water plants.

a) Complete the following table:

Feature Plant Name

Floating leaves Water lily

Carnivorous Grass trigger plant

Filters water Grey rush

Thrives in poor quality water

Soft twig rush, Streaked arrow-grass, Louisiana iris

Provides food Nardoo

Native to South Australia

River buttercup, Leafy twig-sedge

(b) Name one threat to our native water plants.

Introduced water plants can rapidly overtake our waterways threatening native plants. Increased numbers of droughts due to climate change may also threaten their survival.

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9. Web of Life – Underwater viewing (student book page 9)

Walk down to the glass viewing panels next to the biodiversity panel.

Did you know that there is more life in a healthy wetland than in almost any other habitat? Much of it is very small.

Look for water creatures (macro invertebrates) through the glass panel both near the surface and in the water.

(a) Draw one of the animals.

Student drawing of macro invertebrate.

(b) Can you find a match with any animals you can see on the wall panel?

Students match macro invertebrates in the water or ones they have seen in other parts of the wetlands to the drawings on the wall panel.

(c) From observing the wetland and the wall panel, make up a wetland food chain on the diagram below.

Algae Waterboatman Frog Ibis.

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10. Bridge - Storage pond (student book page 9)

The water in the storage pond is ready to be pumped to the garden to water the plants.

(a) Where was water pumped from to get to here?

This water was pumped from the underground aquifer 130 metres underground up to the Storage Pond.

(b) What are the benefits of only storing water here in this pond for a short period of time before using it to water the garden?

Benefits of only having to store water here for a short period of time before using it on the garden are reduced water loss due to evaporation, soakage, reduction in algae growth and less chance of contamination by animal droppings and microorganisms.

(c) How is this water different form the water coming through First Creek?

This water is much cleaner than stormwater entering the wetland because it has been cleaned by the wetlands and has had a final mechanical filter before being stored underground. The filters include;

• Intake filter • Gross pollutant trap • Sediment pond • Plant reed filter • Sand filters pre pumping underground

(d) What are some benefits of using this recycled water?

Benefits of using this recycled water include:

• Increased water available for re-use and less demand on traditional water supplies

• Reduction in pollution of water flowing into rivers and the ocean, increased wildlife habitat.

Literacy opportunity

Water is so important to all life and has a special beauty that many people have written about it. Some ideas are inscribed on the metal circles inlayed into the bridge. Students might be inspired to engage in creative writing here (or find a quiet spot) about water.

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11. Cracked Earth Sculpture – Storing water underground in an aquifer (student book page 10)

On your way to the sculpture, stop at the pump-house and look at the different pumps that draw water from underground into the storage pond and from there into the garden.

(a) What are the advantages of pumping water from this wetland onto the Garden rather than from the River Murray?

Because of the distance water has to be pumped from the River Murray to the Garden is more energy is required, it is more expensive and higher in greenhouse gas production. The river Murray water is also needed for irrigation and environmental flows along the river. This water has less salt and chemicals in it.

Walk over to and stand in the middle of the rock sculpture. Now imagine you have become a microscopic drop of water and you are 100 metres under the ground here, the blocks surrounding you are tiny sand grains!

(b) Can you fit between the grains (blocks)? Students check.

(c) Can all of your class fit between the sand grains?

Class or group checks to see if they can fit between the sand grains (blocks)?

The cracked earth sculpture is a model of an aquifer (or underground water storage), the spaces between sand grains or cracked rock fill up with water seeping from the ground above. Water will be pumped from the wetland into an aquifer 100 metres below for 5 to 8 years, from then on it is expected to supply the garden with 100 mega litres per year.

(d) What are the advantages of storing water in the aquifer rather than a reservoir or tank?

Storing water in an aquifer reduces water loss through evaporation and makes it easier to maintain the quality of water not exposed to contamination above ground.

(e) What are the disadvantages?

Disadvantages might include, possibility of pollution from seepage above, leakage of water from the aquifer and the cost of bores and pumping up to surface.

Numeracy opportunity

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(f) Describe a space that is about a mega litre. A swimming pool. Space is 10 m x 10 m x 10m

12. Floods – good and bad (student book page 10)

Nearby find the creek depth flood marker.

(a) Using the height marker for 1 in 100 year flood, predict what areas of the surrounding garden would be worst affected.

(b) What could be done to prevent the area flooding?

Flood prevention features like levee banks or stormwater pipes can reduce the threat of flooding.

(c) How can flooding be good for the natural environment?

Flooding can be beneficial to the natural environment by spreading nutrient rich silt over a wide area. Floods also spread native plant seed to grow in new places and are essential for the long term health of certain plants like the river red gum. They can have disastrous impacts on buildings, roads and services in built up urban areas of modern cities.

Web Resources A wide range of web resources are available to support your pre and post wetlands visit.

http://www.greenhub.org.au/water/water-for-life/

http://www.waterwatchadelaide.net.au/

http://www.epa.gov/gmpo/education/

http://www.greeningaustralia.org.au/uploads/Our%20Solutions%20-%20Toolkit%20pdfs/NT_14_Water_Tests_Web.pdf

http://www.environment.gov.au/resource/discovering-wetlands-australia

http://melbournewater.com.au/getinvolved/education/educationalresources/Pages/Educational-resources.aspx#TreatmentPlant

http://www.urrbraewetlandlc.org/importance.html

http://www.sawater.com.au/SAWater/Education/LearningProgram/EDLinks.htm