Thursday, 25 June 2015

Healthy waterway report Lachlan

Waterways in chch

We have many different rivers and streams in Christchurch some are natural and some have been man made.

Our groundwater is a natural resource because it has been here before us which means they  are not artificial and if we left the earth then it would still be here.

Ground water connects to springs because springs form into a river and the groundwater flows out. Springs are connected to aquifers because the water from the aquifers are used to make springs.  

Surface and stormwater systems are connected because the surface water goes into the stormwater system and out into the rivers, for example the Avon or Styx river.

Habitats and creatures connections

Some creatures rely on many different ecosystems and habitats in a river to survive.

The common bully lives on freshwater crayfish because a freshwater crayfish is a crustacean and the common bully feeds on crustaceans. Freshwater crayfish helps the mayfly larvae because mayfly larvae like their water clean and freshwater crayfish feeds on sediment.

Pukeko survives on vegetation because pukekos as they walk down the river bank their also scavenging for shoots and roots. Eels live under shade because it keeps the water cool and provide food for it and if algae was in it maybe they could hide under it from predators.

Health of rivers and streams

There are many different indicators that can measure river health. If the river has a ecosystem with different types of macroinvertebrates which means it's a healthy river. If you just find snails and worms with no Macroinvertebrates it means that it is not healthy. There aren't many macroinvertebrates because they prefer waterways that are colder than 15 degrees celsius. They only like waterways colder than 15 degrees because water that is warmer than 15 degrees has less oxygen and even though there water creatures they still need oxygen.

Testing our streams

Our class have gone on a trip to some local waterways. We tested the turbidity and how much algae there is, also trying to figure out how much sediment there was on the streambed. We used a clarity tube to figure out how much sediment there was on the stream bed. We also used the Instream and riparian survey as well as the invertebrates survey.


Here are the results from our assessment at Dudley creek. Dudley creek was good but could have been better because the stream flow had very little rapids and riffles.  The turbidity was murky and I also spotted some erosion, mostly where there were very few bushes and trees.

The algae wasn't to bad because it wasn't in a thick layer but was in long strands and was only in a thin layer which means that the macroinvertebrates have a food source. The shade was ok because there was only 1-3 metres of shade which I personally thought it

could've been better. I thought the vegetation was good because I was seeing lots trees around in some parts.


Suggested changes

  • We need to start planting more native trees and bushes because I've seen some erosion. That's why we need to plant more trees and bushes because the roots make                                                                                  the bank stable

  • We should start to dig out the sediment(mud/dirt) and put more stones in.

  • We need to start and put out more rubbish bins to prevent people from littering and throwing their rubbish in to the river

  • It should be cleaned more often because there's too much old leaves and branches and if we don't get them out the creek would get clogged up and the creek wouldn't be able to flow.

These changes are good for the future generation and kaitiakitanga. Kaitiakitanga means sustaining protecting the land and waterways for future generations like recreation and many more. Mahinga Kai (another maori word) this means food from nature.   

1 comment:

  1. I like I like This is allmost the same my one exsept I don't have a Graf