whats the need of rain water harvesting or water harvesting while you are living in a humid area or near glaciars.
Should i care about water conservation ?
This sounds like a class question, but I'll try to help.
In a humid area, people can still water harvest, or collect water in cisterns. Cisterns are containment vessels for storage of water. The method was once used very commonly in the US even in areas that got a lot of rain. In the mountains of Virgina, my grandparents caught the water off of the roof of their house and directed it into an underground water cistern or tank, made of concrete. They did this for many years until the nearby town put in water pipes into their area to supply water from the local water treatment plant.
This is a good way to reduce water consumption from overused aquifers. In Houston, Texas, we rely on two wate sources, an underground aquifer that is fed from an area 150 miles away, and two lakes. My home uses well water supplied from district wells. So even in a very humid coastal area like Houston, water rationing occurs when the demand for water is high, like right now. The aquifers cannof supply all the demand, so we have to cease watering our yards and plants.
Now if people were to do like my grand parents, and catch the rain water from the roofs of their homes they could use that water for watering plants and other used outside the home. I brew beer and could use it for that since it would be boiled. Pets could use it, or it could be used for flushing toilets, or washing. It is what is called "gray" water, meaning water that is not potable or needs to be treated before it is consumed, by people but would be acceptable for other used other than drinking.
In glacial areas, their is usually a lot of free surface water if below the zone of accumulation. The Zone of Accumulation is the zone where snow does not melt but compacts to make the glacier grow. If below that zone, then the glacial ice will be melting constantly during the day, and may refreeze at night, or not. So water availability would not be a problem unless it is a problem of access. You might have to go down hill to get water and carry it back up, which might make snow/percipitation harvesting desirable. In this case, you would need to melt the snow in order to have free water.
When I worked in United Arab Emirates, water was worth more than oil. So depending on where you live and the amount of fresh water available, the ease with which it can be obtained and the socio-economic class you are in dictates whether water conservation is an important issue for you.