Appendix D - Flood Assessment

R1593: FLOOD ASSESSMENT – 9A JIRRIMA CRESCENT, COOROIBAH




2.2.             PROJECT WORKS

The proposed development will involve a 1 into 2 reconfiguration of lot, with required
stormwater, electrical and services connections. An extract of the proposed
development layout is provided as Figure 3.

3                SITE DESCRIPTION
3.1.             TOPOGRAPHY AND DRAINAGE

The site is traversed by a mapped drainage line which enters from the southern
boundary and exits to the north. The site falls inwards from both the eastern boundary
(Jirrima Crescent) and the western boundary (adjacent lot) towards the drainage line.
The peak elevation of the site is located on the north east corner of proposed Lot 2
at approximately 16.0 metres AHD with a general slope of 3 %. The south west corners
has a peak elevation of approximately 9.5 metres AHD on top of the ridge in this                       Figure 3 – Proposed Site Layout
corner, with a general slope of 2 % to the waterway which is at RL 6.0 near the
northern boundary.

The adjacent lot to the east (9 Jirrima Crescent) slopes towards proposed Lot 2. Some
runoff from the adjacent lots to the south (fronting Illoura Place) has potential to
enter lots 1 and 2 from this direction via overland sheet flow. There is currently no
easement associated with the mapped drainage line, which will provide the lawful
point of discharge for the reconfiguration.

3.2.             FLOODING

An extract from the Noosa Plan Flood Hazard Overlay Map is included as Figure 4,
illustrating the approximate location of inundation associated with the drainage line
on the downstream lot.




                                                                                         Figure 4 – Extract from Noosa Plan Flood Hazard Overlay Map



Environment. Engineering. Education.                                                                                                                   PAGE 2