Feng Shui has been always associated with Water and no doubt it is. Shui 水 in Chinese literally mean water. Water can affect us since it is a vital Qi carrier and activator. In Feng Shui, water is usually associated with wealth of a house. Hence most feng shui master uses water features to help clients activate wealth in the house.
At the same time, I have also meet cases where water features who was supposed to bring wealth to the family, brough accidents and loss of wealth at a very fast rate too.