A river is like a big tube that carries water from one place to another. Rangitata River is a very special river in New Zealand. It starts in the mountains and flows all the way down to the ocean. It is very long and very wide.
The river is very important because it gives water to plants and animals that live near it. People also use the water to drink and to grow crops. Sometimes, people even go fishing in the river to catch fish!
But, sometimes when it rains really hard, the river can get too full and the water can overflow. This can be dangerous because it can cause flooding in nearby towns and farms.
So, people have built big walls called "stopbanks" along the river to keep the water inside the river where it belongs. These stopbanks can help protect people and their homes from flooding.
Overall, the Rangitata River is a very important part of the ecosystem in New Zealand and it provides a lot of benefits to people and animals who rely on it for their needs.