Dear Mr. Michael Bätscher :

Either Problem Specification Option 12 or 14 is used for 2 or more flow structures. Use Option 14 if the upper reservoir is being modeled with level pool assumptions.

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

Sincerely,

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