"Mine drainage" refers to the water that flows out or seeps from abandoned or active mines. It often contains minerals and chemicals that can harm the environment and cause pollution in nearby rivers or groundwater. Full definition
Keeping your hands and feet elevated helps promote drainage of fluid back to your heart. (momtricks.com)
According to him, the river escaped its path into the federal road, due to lack of proper drainage system and bad roads. (dailypost.ng)
If you take any old broken up flower pot or even rocks and put them in the bottom of a crock, it should be enough for drainage for any plant. (theletteredcottage.net)