The water cycle was discovered 100s of years after The Glorious Quran was revealed. It has been mentioned in Quran with great details. A couple of Verses about water cycle are as follows.
“Allah is the One who sends the winds, so they stir up a cloud, then He spreads it in the sky however he wills, and makes it (split) into pieces. Then you see the rain coming out from its midst. So, once He makes it reach those whom He wills from His slaves, they start rejoicing.” [Quran 30:48]
“Have you not seen that Allah sent down water from the sky, then made it penetrate into the earth (and gush forth) in the form of springs? Then He brings forth with it crops of different colors, and afterwards they wither, and you see them turned yellow, then He makes them [scattered] debris. Surely in that there is a lesson for the people of understanding.” [Quran 39:21]