Abstract Several definitions and criteria of the first-flush are being used to assess and control the nonpoint source (diffuse) pollution. The common consensus is that the first-flush is generally noticed in the small catchments (e. g. https://www.lightemupsequences.com/flash-price-Bearington-Willie-B-Mine-Plush-Valentines-Bear-10-Inches-and-Retired-special-buy/