Optimizing the Hydrologic Properties of Urban Soils.

Soil-water relationships are important in almost all landscape types because the movement of water into and through a soil affects water and nutrient availability for plant roots, the incidence of soil erosion, and the degree to which surface runoff occurs. In vegetated landscapes that have not been developed, there are usually sufficient soil macropores and soil porosity to support water storage and movement through the soil. In urban soils, however, the soil hydrologic properties are often characterized by a loss of water retention, restricted water drainage, and increased susceptibility to erosion and surface runoff.  This presentation reviews the specific urban activities that affect the hydrologic properties of soils and then provides management actions that can be employed to optimize the hydrologic properties of urban soils. We include discussion of low impact development (LID) techniques, soil replacement, tillage, compost, and the use of engineered media (structural soils) as tools that landscape managers can use to improve water infiltration and water storage in urban soils.