Wednesday, 24 June 2015

waterway report


Christchurch Waterways
Fresh waterways are things that carry water to places.  For example a stream is a waterway and so is a river, aquifers, tributaries, estuaries and lakes.  There are also man-made ones such as artificial drains, water races, piped systems and retention basins.
Some man-made waterways are used when rain falls from the sky and lands on the concrete. If the water falls onto concrete it becomes surface runoff and it will flow into an artificial drain then it will flow into a river or lake. But if it goes through the the ground and into an aquifer it can get pumped up and used in our taps or it flows into a spring.  A spring is a thing that takes the water out of the aquifer naturally and often goes into wetlands.
A way that natural waterways connect to artificial waterways is the drains and pipes that connect to aquifers. It can take water to a house so it can be used for drinking water, showers, baths, toilets and hoses.
Another connection is the water that comes from the sky becomes stormwater and it flows into rivers and affects our wildlife and their habitats in good and bad ways.

Habitats

In a river ecosystem there are lots of different habitats. A habitat is a place where animals live, for example a river is a natural habitat for a fish.

An ideal habitat for a Canterbury mud fish would be a weed-filled creek bed because they can dig burrows in the mud and it also has food for them such as weeds and submerged plants. As well as all of this it is also an umbrella species which means it is a protector of dragonflies, freshwater mussels and freshwater crayfish. The common bully is not picky so lives in many different habitats like a stream bed because they like to eat the invertebrates who live under stones. A pukeko would prefer to live beside a stream because it likes to eat all the roots that the plants grow. The mudfish and bully are connected because they are both fish and the pukeko and the bully connect because they both live beside/in streams.
It is very important we protect our wildlife habitats because if we don't the wildlife could die and end the food chain. So you don't want to pollute them because that affects habitats and the waterway health.

Healthy waterways
All the things in habitats connect to waterways and the health of a habitat determines the health of the waterways. There are a few signs you can look for.
If the fresh waterway is healthy it will have macroinvertebrates such as stoneflies and mayflies but if it's unhealthy it will only have snails and worms or nothing at all (snails and worms can also live in healthy waterways too). Macroinvertebrates help keep water clean because they eat algae but if it is unhealthy it will have lots of thick algae.
Another sign that waterways are healthy is the water temperature, for example a healthy waterway will be cold and have lots of oxygen which is good for fish but if it is warm it means it has no oxygen and is bad because the fish and macroinvertebrates can't breath.
Like algae, trees are an important part of the river because they help keep the water temperature cold and they stop erosion.  Erosion happens when the dirt slides off the land and into the water.  A way to stop erosion is to plant lots of plants so the roots hold all the dirt in place.
Another way dirt can affect our waterways is that it can create turbidity.  Turbidity is when dirt gets mixed in with the water so it makes the water lose oxygen killing macroinvertebrates and fish.
Looking for these signs can help to protect streams, rivers or any other waterway in Christchurch, and the different animals who live in or around water and their habitats.

Testing our waterways
Our class has tested our local waterways to see their health. Our method was to go to streams to assess their health.  We visited different waterways for example: Dudley creek and a stormwater drain.  We used an “In-stream and riparian habitat survey” which is a sheet that surveys the waterways health.

Waimairi school stormwater drain
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The stormwater drain near waimairi school is in poor condition because it has barely any trees or shrubs hanging over the waterway. So the water will heat up, making it carry no oxygen which is bad for the animals living in it.  It is also unhealthy because there's no algae so the invertebrates have nothing to eat.

There's not much erosion in the waterway because all the grass on the side holds it up using its roots.  There is also some stones and pebbles on the bottom of the waterway which is a good thing because the stones act as filters and stops sediment clouding the water.

The turbidity in the stormwater drain was very clear because there was no water.  There was also no macroinvertebrates because there was no water.  The reliability of the test varied from people and the validity of our tests was high because of different people surveyed different parts of the river on different days.

Changes we could make
The waterways around Christchurch aren't as healthy as they could be, so some changes we could make as a community are to plant more native plants around the stormwater drain so the water becomes colder and habitats are created. Another change we could make to help is to put more stones at the bottom of the waterway.
Why these changes are important
These changes are important because if we don't keep our waterways clean we won't be able to do cool stuff like fishing, swimming, kayaking and other recreation activities. Kaitiakitanga is another reason these changes should be made. Kaitiakitanga is when we only take what we need and only the grown-up fish.  In other words, kaitiakitanga is when we save our resources for further generations so the kids in the future can still swim in our beautiful waterways.

1 comment:

  1. I enjoyed reading this and I learnt something today.
    It made me think of Otematata and all of the waterways down there. When we are next there we should have a look at the water and look for stones on the bottom and for planting around the edge.
    It also made me think about when we fish and how we practice Kaitiakitanga. We only take what we can eat and we only take fish that are a certain length so we keep the fish stocks of baby fish high.
    Well done Lewis.
    Mum

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