I’ve taken pictures of ripples in water from rain dripping off trees before and have thought several times about setting a bowl or other container and letting water drip just to photograph it.  I learned several things from this evening experimenting:  1) use a larger container, 2) use different/better lighting and 3) have an assistant to manage the water flow.  On the other hand, the small bowl I used was a significant contributor to the patterns on the surface of the water.