Testing of the Storm Water Management Model Low Impact Development Modules.

Area of Science:

• Environmental Engineering
• Hydrology
• Water Resource Management

Background:

• Storm Water Management Model (SWMM) is crucial for simulating stormwater and wastewater infrastructure.
• Continuous improvements and rigorous testing verify SWMM's accuracy.
• Low Impact Development (LID) storm control measures are increasingly important for sustainable urban water management.

Purpose of the Study:

• To quantify the accuracy of SWMM in simulating the hydrologic performance of LID storm control measures.
• To evaluate SWMM's performance using a multievent, multiobjective calibration method.
• To identify limitations in SWMM's current LID modules.

Main Methods:

• Quantitative comparison of empirical data with SWMM simulation results.
• Utilized PEST software for parameter estimation in SWMM's LID modules.
• Employed a multievent, multiobjective calibration approach.

Main Results:

• Calibrated LID modules showed high accuracy with an average Nash-Sutcliffe efficiency of 0.81.
• SWMM accurately predicted peak flow timing but often underestimated magnitudes by 10%.
• Average volume reduction simulated by SWMM was 48%.

Conclusions:

• SWMM satisfactorily simulates the hydrologic performance of most (8 out of 9) LID practices.
• A significant limitation exists in SWMM's inability to simulate lateral exfiltration from deep LID structures.
• Further development is needed to address limitations in simulating complex LID behaviors.