3000- Lot 7 & 8 SMP - June 2018 · OPW18/0155

consistent indicating a liner relationship between driving head and
infiltration rate such that:

Infiltration Rate (mm/s) = 4mm/sec + 13.6 x head (m)
Refer to Appendix C for prototype test results.

In order to model the operation of the RIP’s, a spreadsheet has been
developed and utilised for all previous stages of Settlers Cove.

Temporal patterns for Zone 3 from the Australian Rainfall and Runoff,
Volume 2 were applied. These temporal patterns were used in conjunction
with the average rainfall intensities for the Noosa region to create a series of
design storms of varying duration for a 10-year average return interval (ARI).

Temporal patterns were converted to flow rates by breaking each storm event
into a series of short duration storms. A triangular flow verses time
approximation was used for each substorm with substorm flows then added
to produce flow Vs time for RIP inflow.

Outflow and water depth were then calculated through iterations for the
duration of the storm based on the infiltration rate / head relationship
discussed above. A factor of safety of 2.0 was applied to the observed
prototype infiltration rate. Each RIP was then sized to prevent overtopping in
a 10-year ARI storm event of any duration.

Spreadsheet model results for each building are attached in Appendix D.




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S3000/ST4/SMP/June 2018                                                      Page 4 of 3
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