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 eternal dreamz coupons (e.g.10 ha) without on-site monitoring being conducted.However, it is also recommended to come up with a simplistic approach of designing the best management practices (BMPs) to capture and treat certain depth of the initial tonic shower cap storm runoff (e.
g.first 20 mm), which will help reduce the effect of nonpoint source (NPS) pollution.