Compactive processes affect soil hydraulic properties and associated soil water flow. Soil water retention and transport properties are altered in response to changes in pore space geometry. Soil water flow is affected not only by soil hydraulic properties but additionally by the distribution of sources and sinks of water in the soil system. Compaction can alter soil pore geometry, and can also affect sources and sinks of water by changing surface configuration, and crop rooting distribution. This paper reviews the literature and presents data and relationships showing the. effects of compaction on soil hydraulic properties and water flow, presents numerically modeled water flow for some management systems, and identifies future directions for research.