What does "surface runoff" mean?

Overland flow of excess water (with or without accumulated contaminants) that cannot be absorbed by the ground as infiltration.

Surface runoff

Common synonyms include: overland flow, runoff, runoff depth, runoff quantity, runoff volume, runoffs.

noun

noun ·Rare ·Advanced level

Noun

1
Overland flow of excess water (with or without accumulated contaminants) that cannot be absorbed by the ground as infiltration. countable, uncountable
"When there is very heavy rainfall on California hillsides over a prolonged period, there is almost always ensuing surface runoff."

"When there is very heavy rainfall on California hillsides over a prolonged period, there is almost always ensuing surface runoff."

From surface + runoff.