SWMP change reps

in Section 4.1. Therefore, it is considered acceptable as existing stormwater peak flows maintain existing
conditions.

6.4      Climate Change Consideration for Year 2100


To consider the impacts of climate change a 20% increase in rainfall intensity was adopted for the year
2100. The peak flow rates calculated in PC DRAINS and discussed above have incorporated a climate
change rainfall multiplier of 1.2. Figure 6.1 below displays the adopted design criteria in PC DRAINS.




                                     Figure 6.2 – Drains Model Settings




The Hydraulic modelling shows that the water level does not exceed the emergency weir levels and
maintains a freeboard of approximately 100mm. A 1m gap between the basin and RP boundary with
scour protection has been provided where emergency overflow will fall onto natural ground level prior
to sheet flowing across the boundary as per existing drainage conditions. Therefore, the hydraulic
modelling has considered the effects of climate change into the drainage design.




SCG Consulting Engineers                   Page 23                            SCG Ref: 33132(SWMP).RevC