Surface water is water that you can see on top of the ground, like in a river, lake, or ocean. When it rains, some of the water soaks into the ground and some stays on top. This water on top flows downhill and collects in these rivers, lakes or oceans.
Surface water is really important because it gives us a place to swim, fish and play. Plants and animals rely on surface water to survive too. But, sometimes surface water can get dirty with trash or chemicals from factories or farms. So, it's important to take care of our water and make sure it stays clean and safe for everyone and everything that needs it.