The Narran Lake Nature Reserve is situated in the north-west of New South Wales (NSW), approximately 75 kilometres north-west of Walgett and 50 kilometres north-east of Brewarrina. Narran Lake Nature Reserve covers part of a large terminal wetland of the Narran River in NSW at the end of the Condamine River system which flows from Queensland. The Narran River lies within the Murray-Darling Basin. The Ramsar site contains two open water areas, Clear Lake and Back Lake. Annual inflows to the Narran wetlands are highly variable and Back and Clear Lakes will usually retain water for approximately 4-6 months following inundation. The lakes are surrounded by extensive channelised wetlands vegetated with Lignum, River Cooba, and River Red Gum. The eastern half of the Reserve is low, gently undulating, sandy and rocky ridge country. Other vegetation communities within the Ramsar site include sedges and ephemeral herbs, Common Reed, Coolibah and Black Box woodland. Lignum, River Red Gum, River Cooba and Coolibah all require flooding to grow and regenerate. Narran Lake Nature Reserve provides habitat for numerous waterbird species listed under international migratory bird conservation agreements. These include Greenshank, Marsh Sandpiper, Latham’s Snipe, Black-tailed Godwit, Curlew Sandpiper and Sharp-tailed Sandpiper. The extensive area of Lignum is a particularly important habitat for bird breeding events, supporting large nesting colonies of spoonbills, cormorants, and other waterbird species. The Narran Lakes area also has a very high traditional, as well as contemporary, social and spiritual significance Indigenous people. Traditionally, the area was a common meeting place for a number of Indigenous peoples. In present times, the lake area is used by local Indigenous communities for educational purposes. A number of archaeological sites have been found within the Reserve, such as shell middens, hearth sites with clay ovens, quarries, and artefact scatters. Current use of the site is focused on nature conservation, education and recreational activities.
Narran Lake Nature Reserve
Government evidence of impact of climate change:
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Australian Government, Narran Lake Nature Reserve Ramsar Site, Ecological Character Description
Exacerbating this threat is climate change.
Threat Invasive Species Upstream Water Extraction Climate Change Stressor Pigs; foxes and feral cats Invasive plants Golden dodder; Lippia Reduced magnitude of flooding Reduced flooding frequency Increased temperature and evaporation Increased intensity of local rain events Hydrological fragmentation Decreased vegetation health Ecological effects Disruption of critical life stage loss change in habitat Altered community composition Change in physical habitat sedimentation Increased predation on waterbirds Changed wetland type Disruption of critical life stage loss of breeding triggers Component; process; or service Hydrology Services Near natu ral wetland Physical habitat Cultural services Waterbirds Services Waterbird breeding Threatened species Vegetation Services Near natural wetland Physical habitat Threatened species Figure 46 Stressor model of major threats to ecological character of Narran Lake Nature Reserve Ramsar site (after Gross 2003 and Davis and Brock 2008). 5.1 Upstream water extraction There has been significant water resource development in the Condamine Balonne catchment and this has occurred since the advent of irrigated agriculture in the 1960s.
For more discussion on the changes see section 7.2.1. 5.2 Climate change The following are the general impacts from climate change predicted for the western region of New South Wales relevant to the site (from DECCW 2010b) .
By 2050; the climate is virtually certain to be hotter and is also likely to be drier; with storms increasing in frequency and intensity.
The aspects of climate that most directly affect wetland ecology are rainfall (both local and in the catchment); temperature and evaporation as these all fundamentally affect wetland hydrology and the water budget.
The driest period on record occurred between 2000 and 2008 (Figure for up til 2006) and in part is attributed to drought climate change impacts with significant declines in inflows to the system.
Exacerbating this threat is climate change.
Threat Invasive Species Upstream Water Extraction Climate Change Stressor Pigs; foxes and feral cats Invasive plants Golden dodder; Lippia Reduced magnitude of flooding Reduced flooding frequency Increased temperature and evaporation Increased intensity of local rain events Hydrological fragmentation Decreased vegetation health Ecological effects Disruption of critical life stage loss change in habitat Altered community composition Change in physical habitat sedimentation Increased predation on waterbirds Changed wetland type Disruption of critical life stage loss of breeding triggers Component; process; or service Hydrology Services Near natu ral wetland Physical habitat Cultural services Waterbirds Services Waterbird breeding Threatened species Vegetation Services Near natural wetland Physical habitat Threatened species Figure 46 Stressor model of major threats to ecological character of Narran Lake Nature Reserve Ramsar site (after Gross 2003 and Davis and Brock 2008). 5.1 Upstream water extraction There has been significant water resource development in the Condamine Balonne catchment and this has occurred since the advent of irrigated agriculture in the 1960s.
By 2050; the climate is virtually certain to be hotter and is also likely to be drier; with storms increasing in frequency and intensity.
The aspects of climate that most directly affect wetland ecology are rainfall (both local and in the catchment); temperature and evaporation as these all fundamentally affect wetland hydrology and the water budget.
The driest period on record occurred between 2000 and 2008 (Figure for up til 2006) and in part is attributed to drought climate change impacts with significant declines in inflows to the system.
However; the reduction in flooding can not be attributed to climate change alone (M.
Large colonial waterbird breeding event of 50 000 nests occur no less than 1 in 8 years based on frequency of large flood events ( 100 000 megalitres total annual flow at Wilby Wilby).
Threats Drought and increased water extraction from upstream pose a significant threat to the site by altering the hydrology of the site.
Increases in the intensity of flood producing rainfall events are likely to change flood behaviour; but catchment conditions at the time of each rainfall event (soil moisture conditions and levels in major water storages) will affect the degree of change.
Both the average flood size and annual flood volume would reduce; which has the potential to impact on floodplain vegetation associations.
Flood frequency and magnitude would increase somewhat; improving conditions on the lower Balonne River floodplain and for the Narran Lakes system.
Medium Waterbirds colonial breeding events Large colonial waterbird breeding event of 50 000 nests occur no less than 1 in 8 years based on frequency of large flood events ( 100 000 megalitres total annual flow at Wilby Wilby).
This critical service is linked to changes in the frequency and duration of wetland wetting and drying as well as changes in extent and condition of wetland vegetation.
Secondly; the extent of Phragmites reed beds within the lignum shrublands fringing Clear Lake and Long Arm is thought to have increased following the recent 2004 and 2008 flood events (Neil Saintilan and S.
Effects of edaphic factors and flood frequency on the abundance of lignum (Muehlenbeckia florulenta Meissner) (Polygonaceae) on the River Murray Floodplain; South Australia.
There is evidence that numbers are drastically reduced during P Family Scientific name Common name Migration type Ecology biology Clupeidae Nematalosa erebi Bony herring P Terapontidae Bidyanus bidyanus Silver perch P P Leiopotherapon unicolour Spangled perch P winter drought when water temperatures dip below 10 C.
The annual recurrence interval (ARI) set for the period to 2003 was determined using partial series analysis; and represents the benchmark for flood frequency at the time of listing.
Threats Drought and increased water extraction from upstream pose a significant threat to the site by altering the hydrology of the site.
Increases in the intensity of flood producing rainfall events are likely to change flood behaviour; but catchment conditions at the time of each rainfall event (soil moisture conditions and levels in major water storages) will affect the degree of change.
Both the average flood size and annual flood volume would reduce; which has the potential to impact on floodplain vegetation associations.
Flood frequency and magnitude would increase somewhat; improving conditions on the lower Balonne River floodplain and for the Narran Lakes system.
There is evidence that numbers are drastically reduced during P Family Scientific name Common name Migration type Ecology biology Clupeidae Nematalosa erebi Bony herring P Terapontidae Bidyanus bidyanus Silver perch P P Leiopotherapon unicolour Spangled perch P winter drought when water temperatures dip below 10 C.