Available translations: English



PC-QUASAR is a water quality and flow model for river networks. It is designed for river regulatory authorities and water/sewerage utility companies to help manage river water quality. The software is no longer supported by CEH but is available to be downloaded at no charge**.


PC-QUASAR can provide distributions of flow and quality at key sites. This allows river regulators to set effluent consent levels to meet river quality objectives. PC-QUASAR can also provide river flow and water quality estimates at each reach boundary over a period of time. This information can then assess proposed changes in the river's use, flow or quality.

It can model the following determinands:

  • river flow
  • pH
  • nitrate
  • temperature
  • E. coli
  • biochemical oxygen demand (BOD)
  • dissolved oxygen (DO)
  • conservative pollutant or tracer


The PC-QUASAR software is available to download free of charge. It is unsupported apart from the manual provided.

** PC-QUASAR is a 16-bit application that will not run under Windows 7 or later versions. While it may be possible to run PC-QUASAR using a Windows XP emulator or on a virtual PC, CEH offers no recommendation, guidance or support for this.

PC-QUASAR's functionality is similar to the VAX package QUASAR.

Download PC-QUASAR

To download PC-QUASAR please fill out our short online form. 


Button - Download model

A software leaflet was published with the software and is available in Adobe Acrobat Portable Document Format (PDF).  


Button - Download publication