natural action,
natural process,
activity,
action a process existing in or produced by nature (rather than by the intent of human beings); "the action of natural forces"; "volcanic activity"
Verb
leach -
permeate or penetrate gradually; "the fertilizer leached into the ground"
trickle,
filter,
dribble run or flow slowly, as in drops or in an unsteady stream; "water trickled onto the lawn from the broken hose"; "reports began to dribble in"
