If you review the pond summary report you will find your answer...
You specified a maximum pond area of 21,780 ACRES, but I suspect you intended to enter square-feet. This produced a very large pond volume so that the entire inflow was retained with virtually no depth or outflow.
To correct the problem you can either convert your entries to acres -or- uncheck the box for "Large Areas" to switch to square-feet and re-enter the correct values in square-feet.
BTW, there is a dedicated HydroCAD forum that you can use for any future questions. forum789