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Wednesday, 24 June 2015

Waterway report

Christchurch Waterways

Some of the Christchurch fresh waterways are human made and some are natural.

Examples of human made are stormwater drains and artificial drains, and examples of natural waterways are rivers, creeks and streams.

When water drops from the the sky, it hits the concrete and it races down into the storm water drains. Then it flows through pipes and into rivers and lakes. When rain hits roofs, it runs into the gutters and flows through the stormwater system and out into rivers and streams.


A habitat is place where an animal lives. For example, a river is a habitat for a fish and many more fresh water animals. That is an example of a natural habitat. The mud fish relies on the mayfly larvae for food. If all the mayfly larves died, the mud fish would go extinct as well.

It is really important that we keep our streams and rivers really healthy because if we don't keep the rivers and streams healthy most freshwater creatures would die because everything is connected in some way. People littering could also lead to blockages in drains.

Healthy waterways

There are some healthy waterways but there are many unhealthy waterways in Christchurch. To make sure the waterway you are at is healthy you can look at the insects that are swimming in the water. If there are only snails and worms it would be a unhealthy but if you found mayfly larvae and many more fresh water creatures it would be a healthy waterway.

Plus if the waterway has a thin layer of algae it is healthy but a thick layer would be unhealthy.

Also if there are many native trees and bushes it is a healthy waterway, but if there are only a couple it won't be as healthy because the bank could be unstable and there wouldn’t be much shade for the animals in the water.


Our class has visited many different waterway ecosystems like Sticks Mill, Dudley Creek and the storm water drain. At these places we assessed the health of the ecosystem using the "In stream and riparian habitat survey". We were doing this with special equipment (which was just a stick with a sieve on it) and a magnifying glass. We used the TRD (Technical retrieval device) to catch insects. Once we caught the insets we investigated them by finding out what they were, and then put them back into the water. We also tested the turbidity using a turbidity tube.



The storm water drain behind Waimairi school could be in better condition because only a small amount of the water is covered with trees and bushes. This is bad because fussy invertebrates like mayfly larvae, stonefish, and many more freshwater creatures won’t live there. There’s no stones on the bottom of the river either because there is lots of sediment. This is bad because there is nowhere for invertebrates to hide.

Possible Changes

From looking at this stormwater drain there are many possible changes to be made.

  • planting some native trees and bushes to make shade to cool down the water so fussy invertebrates won’t leave. It will also hold up the bank.

  • take out all the rubbish and oils to keep the water clean and so the drains won't get clogged.

  • Dig out all sediment off the bed (the bottom of the waterway) and put in stones.

Why are theses changes important

Theses changes are important because if we don't keep our wildlife alive how would you go fishing? Plus if we don't plant trees and bushes the bank will be unstable because the trees and bushes hold up the bank so if we don't plant the bank could fall. Also if we keep putting oils and rubbish in waterways the oils will create a thick layer of algae which is unhealthy but a thin layer of algae is healthy.

We should also do this because of kaitiakitanga, which means to protect the land and waterways. It is a Maori cultural value (which means it's important). We should keep our waterways healthy for people in the future so they can use them like us. 

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