A Different Approach. Modeling stormwater requires a different approach than water and wastewater systems. With water and wastewater systems, the flows will vary throughout the day and seasonally, but the variations are generally predictable. With stormwater, the flows vary dramatically, from zero most of the time, to extremely high flows during summer thunderstorm events. Snow melt events can also create problems in some areas. AE2S' stormwater modeling experts can deal with whatever Mother Nature throws at them, and are proficient at utilizing models to simulate rainfall events, predict how changes in land use will impact the results, and how the drainage system itself can impact the magnitude and location of flooding.