Hydrologic Simulation Program–Python (HSP²)

The Hydrologic Simulation Program–Python (HSP²) model developed by RESPEC uses modern technology to improve upon its predecessor Hydrologic Simulation Program–FORTAN (HSPF) model.  The RESPEC team developed HSPF over 40 years ago, and since that time, it has been used globally to support water-resource planning and management.  In the US, HSPF receives widespread endorsement as a regulatory tool at all levels of government and is accepted as one of the most accurate and appropriate management tools presently available for the continuous simulation of hydrology and water quality in watersheds. The development of HSP² results in a model that retains all pertinent HSPF functionality, provides a migration path for legacy HSPF applications, removes unnecessary static aspects of the model to represent a dynamic world, and is independent of operating system and hardware.  HSP² is compatible with multiple cores and GPU for acceleration, allows for maintenance and enhancement to occur more readily, and is freely available as an open-source model.  In short, HSP² improves upon HSPF and ensures that a tool is available to assist in developing watershed-based approaches for protecting and restoring our waterbodies throughout the world.


Clients use HSP² for:

  • Functions more robust than HSPF.
  • Flood-control planning and operations.
  • Hydropower studies.
  • River basin and watershed planning.
  • Storm drainage analyses.
  • Water quality planning and management.
  • Point- and nonpoint-source pollution analyses.
  • Soil-erosion and sediment-transport studies.
  • Urban and agricultural best management practices evaluation.
  • Fate; transport; exposure assessment; and control of pesticides, nutrients, and toxic substances.
  • Time-series data storage, analysis, and display.