runoff - run·off (rŭn′ôf′, -ŏf′)

n.
1. a. Water, such as rainfall, and any sediments or other substances carried with it, that is not absorbed by the soil but instead flows away over the ground.
b. The overflow of fluid from a container.
2. An extra election or competition held to decide a winner following an earlier, inconclusive election or competition. https://www.thefreedictionary.com/RUNOFF