Dear Terry :

Note that HEC stands for Hydrologic Engineering Center, the Army Corps
Engineers office that developed the engineering programs HEC-1, HEC-2,
HEC-RAS, etc.

If you have any additional questions or need any further information,
please contact me again.

Sincerely,

Chris E. Maeder, M.S.
Senior Technical Engineer
chris.maeder@bossintl.com