How to keep the water level of a lake constant?

Hello Everyone,

I am running a model for a proposed lake system, we are using water from a nearby river to fill the lake when needed to keep the lake at a relatively consistent water level. At first, I ran the model with no water entering the system to see how much water is needed to enter the lake, then I added a flow boundary to add the water needed. I have done several iterations and I am still not able to get the lake at a relatively constant water level in the lake. Is there an easier way to create an inflow and overflow boundary that will keep the water level consistent?

Thank you for any help.

Hi, I believe that using the water level data for the most downstream points in BC would be helpful in solving your problem.