Sorrow, unhappiness and discouragement are impurities you have allowed within you and which upset your psychic organism, just as poison and other toxic substances upset your physical organism.
If you learn to use the powers of water, you can remedy these states.
Look at water flow, listen to it – whether a spring, a stream or a waterfall, running water frees the solar plexus by carrying off the dark elements that disturbed it. For flowing water is an image of the perpetual renewal of life, and by watching it flow we are influenced by it.
Of course, in the city, it is not always easy to come across springs or waterfalls in everyday life but you can always turn on a tap! It is less poetic but it can be just as effective. What matters is to concentrate on flowing water.