When it comes to water in the West, a lot of it is visible. Snow stacks up high in the mountains then eventually melts and flows down into valleys. It’s easy to see how heavy rains and rushing rivers translate into an abundance of available water. But another important factor of water availability is much harder to see. Beneath the surface, the amount of moisture held in the ground can play a big role in how much water makes it down to rivers and reservoirs – and eventually into the pipes that feed homes and businesses.