Flow Control from Resevoir

[wkchk]

I am working project which design a water distribution systems by EPANET. I would like to ask how can I enforce a specific schedule of source flows into the network from my reservoirs with specific head.

I have tried to change the resevoir to node with negative demand with elevation equal to the total head of the resevoir. However, the head of node cannot maintained. Also, I have tried to install a FCV but it still not working.

Any Ideas of this cases.

Thank You