I've heard that moving water has great positive effects on the mind by actually releasing negative ions into the air. Computer screens, air conditioning and TV's all emit positive ions. This can create an electrical haze that effects moods, sleeplessness and weakness. With such a high volume of water moving through this area, the amount of negative ions begin put off energizes, raises your serotonin levels and creates a feeling of well-being.
If you don't believe the science behind it, just get out there and do it! You can't help but feel amazing. Have you ever seen someone crying in a waterfall or river? No, you haven't.