Bushfire Hazard Assessment & Management Plan v1 - 9A Jirrima Cres, Cooroibah

Bushfire Hazard Assessment & Management Plan v1                                    NCES REF: J000706
Lot 101 on SP168341 – 9a Jirrima Cres, Cooroibah



2    Site Description

2.1 General
The site exists in an area dominated by rural residential allotments on the western side of Lake
Cooroibah. The site measures approximately 4.46ha and has been historically cleared of
vegetation with the remaining vegetation described as a mix of regrowth wet heath and broad-
leaved paperbark open forest.
An existing dwelling is located within the north-east, gaining access to Jirrima Crescent via an
existing access handle flanking the northern boundary. Areas of maintained gardens exist
surrounding the dwelling which includes native regrowth occurring amongst mowed grassed
areas.
Open grassy areas are present over a broad depression within the middle of the site and contain
a mix of regrowth wet heath and broad-leaved paperbark. A defined gully dissects the site from
north to south with adjacent areas corresponding with seasonally inundated floodplain conditions.
A culvert crossing provides access across the gully to the western portion of the site.
Areas of heathland exist flanking the western boundary and extend off site to the west.
Plate 2 details site conditions.




                                   Plate 2 – Site Conditions (Source: Nearmap)

2.2 Topography
The slope of the land is a major determinant of fire behaviour, particularly the slope of the land
under vegetation that contributes to bushfire hazard. Fire burns faster as it travels up slope, via
preheating of unburnt fuels ahead of the fire, increasing the rate of spread and fireline intensity.
Conversely, fires move more slowly as they travel downslope. Fireline intensity (kW/m) is a
function of the rate of spread (QFES 2019).
The site is described as near flat (1º) and exhibits a western to northern aspect. The site reaches
a topographic high of 16m AHD about Jirrima Crescent in the east and a topographic low of 5.5m
AHD about the northern boundary in association with a defined gully line which dissects the site
from north to south and conveys overland flow in a northerly direction.. The central portion of the
site exhibits low topographic conditions with seasonal inundation apparent through the presence
of flora species suited to wetland conditions. Standing water was observed within these areas,




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