xpswmm is a comprehensive software package for dynamic modelling of stormwater, river systems, floodplains and foul water or combined systems.  It combines one-dimensional (1D) calculations for upstream to downstream flow with two-dimensional (2D) overland flow calculations so that you can see what truly happens to your stormwater or sewer system when waters flow, populations increase or catastrophic events hit.

Its use over the last 25 years, as well as its FEMA approval and UK Environment Agency benchmark testing, has made it one of the most stable and well-used simulation software programs in the world. 

xpswmm simulates natural rainfall-runoff processes and the hydraulic performance of drainage systems used to manage our water resources. It allows integrated analysis of flow, pollutant transport and sustainable design measures in engineered and natural systems including ponds, rivers, lakes, overland floodplains and the interaction with groundwater.

APPLICATIONS

xpswmm is a comprehensive hydrologic and hydraulic modelling environment. It is applied to a wide range of water resource management, design and emergency action planning issues every day by thousands of users:

Floodplain Management and River Systems 1D/2D river hydraulic performance Floodplain mapping and flood hazard analysis Evacuation Route planning Interior drainage (levee-protected areas) analysis Culvert and bridge hydraulics Fully coupled urban and river drainage systems Foul Water and Combined Sewer Systems Capacity analysis and collection system optimisation CSO and SSO mitigation planning RDII (rainfall-derived infiltration and inflow) studies Real-time control system performance Water quality analysis

Stormwater Management Stormwater master plans Major/Minor or dual-drainage systems Watershed management master plans Hydromodification Contaminant & sediment loading and transport Pollutant removal 1D/2D Urban flooding Detention pond optimisation Interconnected pond routing Stormwater system design WSUD and BMP analysis

WHY xpswmm?

Holistic Modelling. Hydrology, Hydraulics and Water Quality. Experts know that a change to one element in a system may affect the performance of the entire system. xpswmm allows you to perform fully integrated system modelling — channels, pipes, streets, control structures, ponds, weirs, pumps, catchments, groundwater table, overland floodplains, rain gardens, infiltration trenches and more.

Model the Real World. You need a tool with model elements that accurately reflect the physical realities of your drainage system. The number of available element types, shapes and control parameters are unparalleled compared to free or competing proprietary software packages. Minimise the need for approximations and “modelling tricks” by using xpswmm.

Localisation.  has been customised and localised for many niche markets around the world. Specific hydrologic methods, specialised hydraulic routines and purpose-build output templates will help you model according to local standards.

Regulatory Approval. Widely used and accepted in private practice, it is also EPA tested and FEMA approved. Countless regulatory organisations are familiar with xpswmm and prefer modelling performed with its powerful tools.  

Easily Share Models. XP Solutions offers a free Reader of xpswmm models called xpviewer.  Users encrypt models with this add-on module so that others can view an un-editable model.