The characteristics of the water at the mountain source will be as follows:
- Speed; the speed will be bigger, and this due to the bigger fall through which the water passes down the mountain's steep slopes.
- Temperature; the temperature will be lower, and this is due to the lesser influence of the sun on the water, both, because of its speed, and because of the shade from the forest (assuming there's a forest on the mountain).
- Oxygen level; the oxygen level will be big, because the water in this part is the purest, and doesn't have debris in it, or it has it very small amounts.
- Nutrient level; the nutrient level will be relatively low, because the water is cold and quick, as well as steep, there isn't a big chance for large nutrition base to form in that part of the stream.
