Advanced Hydrologic and Hydraulic Modeling

GeoSWMM accounts for various hydrologic processes that produce runoff from urban areas. These include:

• Time-varying rainfall 
• Evaporation of standing surface water 
• Snow accumulation and melting 
• Rainfall interception from depression storage 
• Infiltration of rainfall into unsaturated soil layers 
• Percolation of infiltrated water into groundwater layers 
• Interflow between groundwater and the drainage system
• Nonlinear reservoir routing of overland flow
• Capture and retention of rainfall/runoff with various types of low impact development (LID) practices

GeoSWMM also contains a flexible set of hydraulic modeling capabilities used to route runoff and external inflows through the drainage system network of pipes, channels, storage/treatment units and diversion structures. These abilities include:

• Handling networks of unlimited size
• Using a wide variety of standard closed and open conduit shapes as well as natural channels
• Modeling special elements such as storage/treatment units, flow dividers, pumps, weirs, and orifices
• Applying external flows and water quality inputs from surface runoff, groundwater interflow, rainfall-dependent infiltration/inflow, dry weather sanitary flow, and user-defined inflows 
• Utilizing either kinematic wave or full dynamic wave flow routing methods
• Modeling various flow regimes, such as backwater; surcharging, reverse flow, and surface ponding
• Applying user-defined dynamic control rules to simulate the operation of pumps, orifice openings, and weirs crest levels.