This is a fairly good attempt, I don't find anything irrelevant here. You have addressed the topic quite well still I would like to add few things which I think should be a part of this essay, you can ignore if you think otherwise.

Third paragraph of your causes:
You can strengthen your point by giving examples of areas where there is enough supply of fresh water throughout the year but people face water shortage and taps in their homes run dry just because of lack of interest and poor management from concerned authorities and leadership. Facing a water crisis despite of so many rivers, glaciers and other water resources is not easy to digest.

Impacts:
1. You can add extensive droughts due to non availability of water and their impacts on economy and health.
2. It can give rise to inter provincial water disputes which already exists as we can see by disagreement on construction of dams but water crisis will worsen the situation.

Remedies:
In causes you have mentioned climate change so there should be something in remedies to cope with that,
- Afforestation campaigns.
- Discouraging cutting of mountains and deforestation for commercial usage of land and urbanization as it badly affects the water cycle and escalate global warming.