what's stagnation of water Share with your friends Share 0 Ishika answered this when water has no movement at all then that water is known as stagnation of water 0 View Full Answer Samarth Shetty answered this when green plants or algae start to grow on top of water then it is called stagementation of water but im not sure of the answer though 1 Tanuj Chaudhary answered this still waterforms stagnant water.it gets contaminated and provides a breeding ground for mosquitos 1