CivilStorm weir loss is not correct in my model

Dear sir / madam,

I am using CivilStrom (Implicit SewerGEMS Dynamic Wave solver) for my model. After checking the results I have realized that the weir losses calculated by the program does not match the manually calculated one although I am using in my manual calculation the same equation the program is using. Can you please advise what is the reason behind that difference?

As per the program the weir is placed on the down stream of CO-110 and has the following properties @ Time 0.95:

1- Weir elevation = 98.300 m

2- Weir length = 1.9 m

3- Weir Coefficient = 1.84

4- Flow at Time 0.95 ~ 940.121m3/hr

5- Hydraulic grade line (out) = 98.6249 m

Which means that as per the program the Water depth above the weir (Weir losses) = 98.6249-98.3=0.3249m

As per manual calculation using the same equation the program is using:

940.121/3600 = 1.84 x 1.9 x h^1.5

h^1.5 = 0.747 >> h = 0.175m

If we compare the program calculated losses of 0.3249m with the manually calculated loss of 0.175m we can see a big difference of around 80% extra loss !

I know that if we have one weir in the whole model it might not be a problem but imagine having a couple of weirs in the model, then we can have a serious issue. 

Can you please explain from where this difference is coming?

I have attached the model for your reference0508.Using the - Implicit (SewerGEMS Dynamic Wave) - solver