flow output is lower then expected (Rational method check)

[mvanitallie]

Per the attached, I would have expected the Q100 / 1%AEP to be more around 330l/s (Rational Method check of total catchment), not 130l/s. 

This seems like a large discrepancy.  Any thoughts?

IDF below I made up from BOM (185mm/h is the 5min Q100)

0 0 0 0
64.6 48.9 28.4 18.9
88.8 66.9 38.2 25.2
105 79 44.7 29.4
127 95.1 53.5 35
159 118 66 42.9
185 137 76.3 49.4

[mvanitallie]

now with the model