6. Wet Basement or Crawl Space A number of circumstances can cause a wet basement or crawl space. First, it's important that gutters are clean and downspouts divert water away from the house, according to Mark Kuzila, director of the Conservation and Survey Division at the University of Nebraska at Lincoln. If water from a downspout is puddling around the foundation, divert the water by extending the downspout at least 10 feet from the house. Surface drainage is also important. Watch how the water puddles the next time it rains. Fill any low spots that puddle within 10 feet of the foundation. For best drainage, the land surrounding your house should slope away from the foundation at a rate of 1 inch per foot, including the driveway, sidewalk, and patio. Problems with subsurface water are generally more serious and will require professional help. The least intrusive solution is to install a sump pump, but when subsurface water is putting pressure on basement walls, it might also be necessary to install a subsurface drainage system. This involves excavating around the foundation and installing 4-inch drainage pipe covered with gravel. In severe cases you may need to contact a soil engineer to investigate the depth and direction of the subsurface water.