Reedy Lake is a large freshwater wetland of approximately 550 ha which forms part of the Lake Connewarre Complex and the Port Phillip Bay (Western Shoreline) and Bellarine Peninsula Ramsar site.

The Reedy Lake Integrated Monitoring Program is a biophysical monitoring program to assess the outcomes of the implementation of the Reedy Lake wetting and drying regime. A key focus was monitoring changes in water and sediment quality during the drying regime to assess and manage potential risks from acid sulphate soil activation and impacts from contaminants. The low partial drying of Reedy Lake maintained water levels at >0.0 m AHD. 

Gorski,J
Lind, P
Retallick,R
Coates,F

Reedy Lake is a large freshwater wetland of approximately 550 ha which forms part of the Lake Connewarre Complex and the Port Phillip Bay (Western Shoreline) and Bellarine Peninsula Ramsar site. 

The Reedy Lake Integrated Monitoring Program is a biophysical monitoring program to assess the outcomes of the implementation of the Reedy Lake wetting and drying regime. A key focus was monitoring changes in water and sediment quality during the drying regime to assess and manage potential risks from acid sulphate soil activation and impacts from contaminants. The low partial drying of Reedy Lake maintained water levels at >0.0 m AHD. 

Reedy Lake is a large freshwater wetland of approximately 550 ha which forms part of the Lake Connewarre Complex and the Port Phillip Bay (Western Shoreline) and Bellarine Peninsula Ramsar site (DSE, 2003). The Seasonal Watering Proposal for the Lower Barwon Wetlands 2017 -18 defines a four year wetting drying regime for Reedy Lake which includes:  a low-partial dry summer regime in one year  low water levels in the following two years and  a full water level year. All four years include a full water level in winter. The Reedy Lake Integrated Monitoring Program is a biophysical monitoring program to assess the outcomes of the implementation of the Reedy Lake wetting and drying regime. A key focus was monitoring changes in water and sediment quality during the drying regime to assess and manage potential risks from acid sulphate soil activation and impacts from contaminants. The low partial drying of Reedy Lake maintained water levels at >0.0 m AHD. Outcomes of the Reedy Lake Integrated Monitoring Program include: Surface water, sediment and groundwater  Monitoring for surface water, sediment and groundwater indicated that there were marginal, if any, change to the physicochemical conditions sediment, surface water and groundwater of Reedy Lake during the low-partial drying regime.  The low-partial drying, maintained at >0m did not result in a short-term adverse impact. Coastal Acid Sulphate Soils was not generated and there was no increase in metal concentrations which are comparable to ANZECC water quality guidelines.  Subsequent drying events are unlikely to generate acid events or liberate metals from sediments, which could impact the ecological value of Reedy Lake. Fish  European Carp were the numerically dominant fish species (particularly in deeper areas), followed by the native Common Galaxias and Small-mouthed Hardyhead.  Maintenance of water levels at 0.0 m AHD or above is unlikely to have a major impact on native fish species. All native fish species tolerate a range of salinities, and any reduction in native fish populations in Reedy Lake as a result of drying would be replenished through recruitment from the Barwon River as the lake fills.  Maintaining water levels at 0.0 m would limit adverse water quality conditions and reduce impacts of potential threats to native fish communities from increased competition for resources and predation (e.g. by carp) and adverse water quality (pH, dissolved oxygen).  Surveillance and monitoring of carp movement during the drying regime identified opportunities for eradication of carp when water levels are low and carp congregate in the outlet channel. Concentration of individuals and physical removal could be implemented at the outlet channel culverts. GHD | Report for Corangamite Catchment - Integrated Monitoring Report, 3134598 | ii Birds  The monitoring in January 2017 encountered very dry conditions at the lake. Consequently, a lower number of waterbirds were seen and no shorebirds/waders were seen other than Masked Lapwings (17% of the wetland-associated species and 43% of the non-wetland-associated species were recorded).  The general absence of shorebirds and waterbirds indicates a short-term response by the birds to the lowered water level, and should not be considered a long-term response to the onset of the altered watering regime.  A review of previous data identified it is difficult to determine whether changes in bird numbers at Reedy Lake are influenced by changing water levels at the lake or by changes in habitat availability and/or quality elsewhere. The value and usefulness of historical data for establishing baseline data are limited by inconsistent data-collection methods over previous years or projects. Amphibians Frog monitoring has identified the five species identified during surveys have some differences in habitat preferences. Frog populations will respond to the wetting and drying regime in accordance with habitat availability as influenced by water levels.  The eastern froglet (Crinia signifera) and spotted grass frog (Limnodynastes tasmaniensis) appear to favour habitats around the margins of the lake responding to higher water levels.  The southern brown tree frog (Litoria ewingi) appears to favour taller vegetated habitats within the deeper and more permanent parts of the lake where water levels are more persistent.  The nationally listed growling grass frog (Litoria raniformis) and eastern banjo frog (Limnodynastes dumerili) are not present in large numbers around the lake. Both species favour deeper and more permanent parts of the lake. Vegetation  Vegetation monitoring provided a baseline of vegetation distribution and abundance. The program identified relatively minor changes in most species and their distribution and those of plant functional groups compared to previous monitoring (2013/14).  While the Phragmites and Typha monitoring transects established in 2013/2014 were not re-measured as part of the current project some of the quadrat data indicate further spread of reeds and rushes from consistently high water levels.  Vegetation monitoring results indicate that consistently elevated water levels in Reedy Lake have continued to influence vegetation quality, function and extent, favouring deeper water species (native and exotic), disadvantaging other native species that respond to water fluctuations and encouraging the spread of weeds.