Forest Hydrologist: My favorite science experience is being outside during a rainstorm. As a forest hydrologist, I study what happens to water from the time it falls from the sky until it gets to a stream. During a rainstorm is the best chance I have to really understand what is happening. Did you know that only a tiny fraction of rainfall falls directly on a stream? Most of it falls on land and must travel along the ground’s surface or through the soil to get to the stream. Everything the water encounters as it flows towards the stream will affect how clean the water is when it gets to the stream. That is why understanding hydrology is so important to keeping our streams and rivers clean.