Permeability of soil is an important property of soil study as a civil engineering point of view.
Permeability of a soil is the property to allow water to pass from a series of pores.
Following are some factors which affect the permeability
- Shape and size of the soil particles
- Temperature and climatic conditions
- Degree of saturation of soil
- The specific surface area of the particles present in the soil
- Void ratio of soil
- Properties of water absorption
- Nature of soil
- Mechanical properties of soil
- Characteristics of expansion and contraction
But I recommend you to read details about all the above properties from the article:
https://theconstructor.org/geotechnical/factors-affecting-soil-permeability/29563/11