The swstat application calculates Surface Water STATistics. It was developed by the USGS and uses the WDM time-series format.
Created attachment 83936 [details] swstat-4.1.ebuild
Created attachment 83937 [details, diff] patch_swstat.diff (put into files folder) Patches the code to compile with 'g77' on Linux and specifies the location of the message file.
The USGS ebuilds are so far away from being useful to anyone, that I want to withdraw from consideration. Also, I now have much nicer versions that USGS won't support so I am at a crossroads about what to do.