Some ideas about layout.
<COMPANY>/ <COMPONENT>/ - fixed layout with all optional folders (extept src/) doc/ src/ shared/ - external libraries used by this component examples/
For release planning it would be also good to introduce branches/tags there
to release each of the components separately:
trunk/MyOpenSource/ HEC/ RAS/ <---------- current development version of RAS src/ examples/ ... USGS/ MODFLOW/ ... CUASHI/ WaterOneFlow/ ... tags/MyOpenSource/ HEC/ RAS-1.0/ <------ SVN copy of the trunk released on DD.MM.YYYY src/ examples/ ... RAS-2.0/ src/ examples/ ... USGS/ MODFLOW-2005.1/ ... MODFLOW-2008/ ...