Project Details

Modernizing HSPF modeling code to maximize results.

Client: RESPEC Research and Development Project
Time Span: 2014 - Present
Location: Various


HSPF has been the US Environmental Protection Agency's (EPA's) standard tool for watershed-based assessment and planning because it is considered to be the most accurate and appropriate management tool for these purposes. In the US, HSPF is a key model that is used for developing complex Total Maximum Daily Load (TMDL) assessments and assessing the effectiveness of restoration and protection scenarios. The HSPF code is written in FORTRAN 77, which was state-of-the-art at the time of its development; however, no significant updates to the program have been made for over 30 years, and it is becoming increasingly difficult to maintain and enhance algorithms on current operating systems. In addition, HSPF's ability to link with modern visualization and analysis tools is limited.

To advance this model, RESPEC invested internal research dollars to convert HSPF from FORTRAN 77 to Python, thereby increasing functionality and data validation. The new model is called HSP2. Part of the research development project is designing HSP2 to work with other tools and modeling software while providing easy compatibility with software that supports sensitivity studies, optimization, and uncertainty analysis.

Switching from the historical model of engineers and scientists who employ information technology (IT) to engineers and scientists who collaborate with IT experts has resulted in incredible returns on RESPEC's investments in developing HSPF tools and converting the code to a more modern language.