Narellan Creek Overland Flood Study (Vol 1) - Flipbook - Page 59
Narellan Creek Catchment
Flood Study
floods). A summary of the blockage scenarios that were adopted for each design flood is
provided in Appendix D and is also summarised below:
Low Blockage Scenario – 50% AEP, 20% AEP and 10% AEP events
Medium Blockage Scenario – 5%, 2%, 1% and 0.5% AEP events
High Blockage Scenario – 0.2% AEP and PMF events
The impact of alternate blockage scenarios was assessed as part of the sensitivity analysis
(refer Section 6.3.3).
Stormwater Blockage
Stormwater inlets can also become partially blocked during significant rainfall events
because of urban debris being mobilised by runoff. To account for the reduced inlet capacity
that is afforded by blockage, blockage factors were applied to all stormwater pits in the
TUFLOW model. This included a 20% blockage factor for
