A negative slope driveway is one that slopes from the street toward the garage or house, allowing storm water runoff and snow melt to drain toward the garage or house, which causes ponding and flooding conditions in front of or in the garage or along the length of the driveway. A negative slope can also cause flooding in the garage or allow water to seep in around the foundation and into the basement of the home. A negative slope driveway can also have a negative effect in winter: After the street is cleared of snow and salt or other road treatment, it can wash down the driveway. Icy conditions can also occur if the moisture freezes, making exiting the driveway difficult and potentially dangerous. A negative sloped driveway is not reflective of normal design standards, but sometimes the lay of the land necessitates such a slope.