A stormwater pollutant separator system is provided with the system having a stormwater pollutant separator, a by-pass system, an intake conduit and an outflow conduit connected together. The stormwater pollutant separator includes a chamber with a weir plate and siphon plate therein. The chamber has first, second, and third sections. The first section is located between the chamber first end and the weir plate. The second section is located between the weir plate and siphon plate. The third section is located between the siphon plate and the chamber second end. In one embodiment the third section has filter material placed intermediate the siphon (sometimes referred to as the second weir) plate and the second end plate. A method for separating material and pollutants from stormwater drainage is also disclosed with the method including the steps of inducing the stormwater drainage initially into a stormwater pollutant separator, containing the majority of all non-floating and floating material by the use of the weir plate and siphon plate respectively, discharging the stormwater drainage therefrom, providing a by-pass system for introduction of stormwater drainage overflow thereinto, and combining all the discharging stormwater drainage together.