There is no body of surface water that is completely stationary. Even seemingly still bodies of water, like lakes and ponds, have currents and movements caused by factors like:

* Wind: Wind creates waves and surface currents.

* Temperature: Temperature differences create convection currents within the water.

* Gravity: Gravity pulls water towards the center of the Earth, causing slight movements and shifts.

* Tidal forces: The moon and sun's gravitational pull create tides in oceans, and even smaller bodies of water are affected to some degree.

Even a perfectly still glass of water will have microscopic movements due to these factors.