how to reduce continuity error in specific pond from model?

I have run my model and received a very high continuity error in a specific pond in my model. My pond is going to an outlet structure and then an oufall somewhere else in the model is using that pond for a boundary condition. 

When i plot HGL, flow in and flow out as you see how wacky the pond flow in and out is going and not stable. See below.

I have plotted other ponds in my model to compare and none are like that except for the two ponds that are giving me high continuity errors. 

I am not sure how to fix that so the continuity error reduces in my model. 

Please advise and let me know if you need any other information to assist with this inquiry. 

thanks,