Infiltration Through Disturbed Urban Soils

This research examined a common, but poorly understood, problem associated with land development, namely the modifications made to soil structure and the associated reduced rainfall infiltration and increased runoff. More than 150 infiltration tests were conducted in disturbed urban soils and the data was compared with the site conditions. A complete factorial experiment fully examined the effects, and interactions, of soil texture, soil moisture, and compaction. Age since development was also briefly examined. The major finding was that compaction had dramatic effects on infiltration rates through sandy soils, while compaction was generally just as important as soil moisture at sites with predominately clay rich soils. Moisture levels had little effect on infiltration rates at sandy sites. Because of the large amounts of variability in the infiltration rates found, it is important that engineers obtain local data to estimate the infiltration rates associated with local development practices.