Sandy Soils

• Sandy soils have the smallest particles and are incredibly porous, leaving plenty of space in between particles for water to flow. Drainage is fastest with sandy soils since water flows rapidly through the layers. While they take water away from the surface, they're not always the best type of soil because they allow pollutants in the water to seep into the ground. Plant roots do not have adequate time to absorb the water. But, if you want water to drain away from the surface around your home, sandy soils are ideal.
  
  

Loamy Soils

• Loamy soils are the best to grow plants in because they have a comfortable rate of water retention and drainage. They allow enough water to pass through for plant roots to take nutrients from, while at the same time not allowing water to pass through too fast. If you want to increase drainage capacity in your yard, loamy soils will serve the purpose as long as you don't live in a tropical area with excessive rain fall.
  
  

Clay Soils

• Clay soils have the largest particles and are not porous. Water cannot penetrate through the layers, and runoff becomes a problem. Water builds up on the surface, while the layers at the bottom become dry. Clay soils are not ideal for drainage.
  
  

Drainage Rating

• Soil scientists from the USDA Natural Resources Conservation Service have a scale of seven classes to measure soil drainage more accurately based on the texture of soil and exposure to water. They include very poorly drained to poorly drained, somewhat poorly drained, moderately well drained, well drained, and somewhat excessively drained to excessively drained. The optimal soil classification for plant growth depends on the species, but for drainage away from your home, you'll want excessive drainage if you have no desire to grow plants in the area.