In a hard rain the water overflows into rivulets that race downhill to streams or pond. The water that percolates into the soil then becomes groundwater. It trickles through pore spaces in sand or gravel or between fractures in rocks to discharge into a spring or a stream. Plant roots absorb some of the groundwater, pull it up their stems and trunks to their leaves, and release it into the atmosphere. There it joins other water vapor evaporated from streams, lakes, or the ocean.
Water droplets condense around microscopic particles of dust and salt to form clouds.
When the clouds become saturated, the water falls back to earth as rain or snow and rejoins the stream's journey to the sea. In Maine, over 33,000 mapped miles of flowing water are part of this process that has been recycling water for billions of years. This process is called the hydrologic cycle . From its source to the sea Streams are like the capillaries and blood vessels that connect to the major arteries, the rivers. But unlike our body's circulation system, the smaller channels deliver most of the water and food to the bigger ones.