A storm drain , storm sewer ( U.S. ) , stormwater drain ( Australia and New Zealand ) or surface water system ( UK ) is designed to drain extra rain and ground water from paved streets , parking lots , sidewalks , and roofs . A storm drain , storm sewer ( U.S. ) , stormwater drain ( Australia and New Zealand ) or drainage well system ( UK ) or simply a drain or drain system is designed to drain excess rain and ground water from paved streets , parking lots , sidewalks , and roofs .