Biodiversity Strategy - Gosford City Council - NSW Government

with the public's general lack of understanding of fire has resulted in an 'ad hoc'and reactive
approach to fire management across the state. Large areas of bushland adjoining existing
development have been (and continue to be) underscrubbed and / or cleared illegally in the
name of hazard reduction.
There are some misconceptions regarding actions to reduce bushfire risk that can cause
environmental harm. The following facts need to be emphasised (Dalby -Ball 2004):
• Trees often protect homes from ember attack (the major cause of house loss).
Property owners need to control fine fuels (leaves and twigs) and not in most cases
remove entire trees.
• Large fallen logs and tree hollows are essential habitat for native fauna. Logs do not
cause bushfires and while they should be away from dwellings they should be
retained elsewhere on site.
• Managing ground and mid-level vegetation. Being fire safe is often portrayed as
having large areas of cleared lawn. The question is how much open area is required
to minimise risk and how much mid and ground level vegetation can be retained.
In addition to this, fire management agencies have conditioned the community to believe that
burning is the only answer to reducing the impacts of fire and it must be done every year for
them to be safe. Unless we turn this around we will never move away from the hysteria created
each year by people with little understanding of fuel management works achieved in the
community (Anderson 2004).
A - 7.9
Hydrological Changes and Environmental Flows
The waterways in the Gosford LGA have been heavily modified since human settlement. Many
were originally dammed to supply water for agricultural uses. Since then, urban development
has increased the velocity and volume of stormwater flows and erosion in waterways. All of
these factors have contributed to a loss of biodiversity. Despite this Gosford City is still blessed
with significant and remarkable natural and near natural waterways and associated riparian
vegetation including wetlands, saltmarshes and swamp forests. Also, there are the major
estuaries that continue to support aquatic native species and ecosystems.
As development increases, natural creeks and watercourses, particularly in older, developed
areas, have lost their natural features and storage capability through the process of
channelisation whereby creeks and rivers are converted to concrete lined stormwater channels
or piped underground. The loss in storage area is mainly within the overbank floodplains and is
caused by development filling in the floodplain areas. The increase in sealed road and
pavement surfaces has lead to an increase in the volume and velocity of stormwater runoff. This
results in increased flood levels and flow velocities in affected creeks and watercourses,
resulting in erosion of the bed and banks and loss of riparian vegetation. (Gosford City Council
1999). More regulated systems such as channelised creeks and waterways favour pest species
(such as Salvinia and Alligator Weed that already infest waterways in the Gosford LGA.).
Stormwater control structures such as levees, weirs and culverts can also impede fish passage.
Environmental flows describe freshwater flow that is maintained solely for environmental
reasons, to maintain the health and biodiversity of a particular water-related entity, such as a
river, wetland, groundwater system or estuary. Environmental flows are deemed essential to
minimise the negative influences on the health of aquatic ecosystems resulting from alterations
to flow regimes. The impacts on estuarine ecosystems caused by changes to inflow regimes
can be summarised as six key processes (Freewater 2004):
Biodiversity - Technical Report Page 161