Our different rivers
We have lots of different types of waterways in Christchurch some are human made some are natural like Ōtakarō, Styx river, Waimakariri, springs and estuaries. Some are man made too like retention basins, piped systems and water races. Most of them connect up together.
I think groundwater is connected to drinking water because the groundwater starts underground then works it way through a tunnel to our drinking water. Groundwater is natural.
Surface and stormwater connects to drains and the stormwater system because the surface water is rain that falls onto flat surfaces like house and concrete then runs from the
ground into our drain and the stormwater system and eventually goes out to sea through our rivers.
Wetlands connect to floods and droughts they act like a sponge to prevent floods and droughts where are wetlands located in Christchurch City. Another important connection is the aquifers and the springs because the aquifers are underground but when they come to a rock the shoot up these are our springs they shoot up to land and flow into our rivers.
An ecosystem is a river full of creatures that rely on habitats but an ecosystem can also be habitats and creatures in an ecosystem you can connect creatures up together. I have been doing this these are some of my connections:
Koura (also known as freshwater crayfish) is connected with kowara (Canterbury mudfish) wetlands or grassy stream beds. Submerged plants is connected to pukeko because they protect their habitat and other species. One of these species is the freshwater crayfish.
The mudfish is also connected to submerged plants because it spends most of its time in them. Pukeko likes to explore in and out of the stream bank. Another connection is vegetation and pukeko because the pukeko likes to eat shoots and roots from the plants. Another thing pukeko likes to do is find invertebrates in grassy beds as well one of these invertebrates is the mayfly larvae. The mayfly larvae is a very fussy invertebrate about the water temperature it likes the water cool and clean.
Another connection is the water temperature and the shade of the stream because the shade effects the water temperature if there is lots of trees shading the stream it keeps the water nice and cool but if the water has less shade of trees the water gets a higher temperature for a long period of time the creatures of the stream die and only some survive it makes the water unhealthy.
Healthy and unhealthy streams
There are lots of indicators that tell if a stream is healthy or unhealthy some indicators to tell an unhealthy stream is that the water is warmer than 20 degrees it kills most macroinvertebrates but if the water is 15 degrees lots of macroinvertebrates are in a stream and it means the stream is very healthy.
Another indicator is there is only macroinvertebrates in the stream are slugs,snails and worms these creatures are not fussy they live in both healthy and unhealthy streams in a healthy stream there will be worms and snails as well as stoneflies mayflies and caddisfly larvae these species only live in clean water because they are fussy.
Another indicator is the how thick the algae is if the algae is a thick mat you can tell that the stream is unhealthy because it will be too bushy and creatures of the stream only like thin strips across the streams floor.
One more indicator is the water clarity and turbidity because if the stream is unhealthy then there will be lots of dirt and algae and most macroinvertebrates like clean cool streams to tell if a stream is healthy there will be clean fresh water and the color will not be murky.
Measuring our stream
Our class visited some local streams we evaluated them by having an invertebrate survey. An invertebrate survey is a sheet with lots of invertebrates you will find in local waterways there is a box that you write in the amount of bugs that you found next to that there is another box that tells you how fussy they are.
Another thing we evaluated with was the riparian zone survey this asks seven questions to us.
1. What is the streamflow like?
2. What is the shade over the stream like?
3. How much sediment (dirt) is there on the stream bank?
4. How stable is the stream bank?
5. How far does the buffer of vegetation extend from the water's edge?
6. What types of plants are surrounding the stream?
7. How much algae is in the river?
It has score 8 score 6 score 4 and score 2 you choose the number for each question then you add all the numbers up together then score excellent, good, fair and poor.
Another thing we evaluated was the clarity tube this a plastic tube with a black magnetic circle in the tube that you pull up and down what you use this for is the water clarity first use the water from the local stream second we insert the water into the tube third see how far the you can see the black circle. Another similar tool is the secchi disc.
A very important tool is our T.R.D (technical retrieval device) and tray. A T.R.D is actually a sieve on a stick. This was very important because when we used this we took our T.R.Ds and dunked them into the water with the macro invertebrates in it and then loaded the stuff we found into the tray then examined it with M.R.D (miniature retrieval device - a spoon) for the macroinvertebrates.
Dudley Creek, the stream in St James Park and nearby, is a reasonable stream. Some of these reasons are:
Less than 25% has sediment cover. The reason for this is there is some signs of erosion and this reason is all the trees that have been planted have been planted away from the stream bank this could be that the people that have planted these trees have planted them away from the bank thinking that the trees might fall into the stream. Another reason could be the water was moving quite slowly so the dirt could easily fall into the river. The river could be running slowly because people have not dropped logs or heavy big stones into the river to create rapids and riffles.
Some more evidence is the shade over the stream. No trees overhang the stream making it shaded and if it is shaded more macroinvertebrates will be in the stream. Maybe no trees overhang the stream because they have not have a change of plants in a long time and if they plant trees now they would focus more in the shade for them.
Another thing that could be improved is the amount of native trees. At the moment there are non native trees that don't overhang the stream and small plants that sit a few paces away from the stream bed. The reason for this is probably the landowners of Dudley creek have not bothered or have not even thought about planting native trees. They might have not even known that it would be better for the stream.
My last reason the stream is in reasonable condition is the plants and and trees extend from 3-9 meters from the water's edge. The reason could be that the road bridges and pavement are blocking the buffer of vegetation from growing any more.
The validity of this report can be different because of opinion- this is what I have reported on what I saw, but you could have seen this differently. Well think differently and that is fine. In addition You may disagree with my statements but I was judging by one point of the stream you could have seen another part of the stream and would have judged it differently.
I propose that we should take the following action:
- To buy more overhanging native trees on the stream bank.
- Drop large sticks and logs and stones to create rapids that invertebrates like.
- To fill as much as you can of the riparian zone as possible.
- To put try and get the sediment and algae out of the water.
- Research what plants would be good for the stream.
- Dudley creek is a stream near a park so I would suggest making sure dog owners are picking up their doggy doos by inserting more rubbish bins.
We should do this because the kaitiakitanga means we want this river to be sustainable. That means we want our future generations to be able to use it for recreation and be able to look after our Christchurch land. We want them to be able to experience all the facilities that we have been able to experience and love. Our ancestors have been able to keep these rivers for us so we want our future generations too. I like to think about the Maori culture many years ago, the most of the things they relied on rivers and birds not the new Ipad mini, TVs and hamburgers this list could go on all day. We don't so much now rely on it because all people think about is money. I want my future generations to have as much use of the river as we do now.