* Clay: Clay particles are very small and tightly packed, leaving little space for water to infiltrate. Clay soils are known for being dense and having poor drainage.

* Compacted Soil: Soil that has been compressed, often due to heavy machinery or foot traffic, has reduced pore space and therefore decreased water infiltration.

* Organic Matter (in some cases): While organic matter usually improves drainage, a very high amount of organic matter, like in peat bogs, can create a waterlogged environment due to its water-holding capacity.

* Impervious Surfaces: Concrete, asphalt, and other non-porous surfaces prevent water from infiltrating the ground at all.

It's important to remember: The exact reason for poor drainage can vary depending on the specific composition of the soil and the surrounding environment.