Drainage is the process of moving water away from an area. When it rains, the water needs a place to go so it doesn’t stand in one place. To do this, people use things called drains. Drains are like small pipes that lead the water away from where it was and down into rivers, lakes, or the ground. Drainage helps keep your yard drier so it doesn’t get too wet and muddy, and it helps keep the water around us clean.