Nooksack River, WA
Project: Whatcom County

Modern hydrologic simulation for today’s water resource facilities


Hydrologic Simulation Program–Fortran (HSPF) was assembled for the U.S. EPA in 1980 based on twenty years of research on hydrologic process modeling at Stanford and Hydrocomp. Stanford, the National Science Foundation, and the U.S. EPA Laboratory in Athens, Georgia assisted in funding the research. The EPA felt the Fortran code would be advantageous for hydrologic simulation. The HSPF developed the Stanford Watershed Model series, sediment and radio-nuclide transport algorithms, and agricultural chemical transport models (PTR and ARM).

HSPF is comprehensive and utilized throughout North America and internationally, and both the U.S EPA and the USGS distribute HSPF.

HSPF’s continued use almost 40 years is a tribute to the skill of its developers. It is, however, legacy code. and computer hardware, compilers, programming conventions, graphics and data management methods are dramatically different and evolving.

Hydrocomp Forecast and Analysis Model (HFAM) is based on its predecessors. However, HFAM has a very different structure. It is object code (EMBARCADERO DELPHI), and all input and output (I/O) is XML that conforms to Schemas.
Hydrocomp built HFAM for both historical analysis and probabilistic (or ensemble) forecasting for water resource facilities. We have rebuilt the core structure of HFAM three times to enhance ease of use, and each version exploited current hardware, software, and operating system advances (e.g. 64-bit address space).