### id262791725 water causes structural damage > Water is another challenge with retaining walls. Not only does water pressure add to the earth pressure, in some climates it can freeze. When water freezes, it expands with a force that is nearly impossible to restrain, and you don’t want that happening to the face of a wall. Most large walls are built with drainage systems to prevent water from building up. Keep an eye out for holes through the face of the wall that can let water out, called weepholes, or pipes that collect and carry the water away. - [View Highlight](https://read.readwise.io/read/01fqy7b8pefd7m09bb7h97xr7f) - [[Why Retaining Walls Collapse by Grady Hillhouse#id262791725 water causes structural damage|View in Vault]]