Groundwater in this case is the primary abiotic factor that inhibits organism from being preserved after been buried. After being buried, decomposers here becomes the biotic factors that eat up dead bodies.
It is also known that sedimentary basins encounters a certain change in its subsidence rate over time, and eustatic sea level changes continuously, causing depth to variations in groundwater and lakes, ocean temperature, spreading rates, continental collision and cracks, and sedimentation in ocean basins.
It is important for the cell to be able to bring necessary nutrients immedriately where it needs to and to be able to dispose of harmful byproducts of the cell process. It is equally important to be able to regulate water concentration.