Download Introduction - Surf Coast Shire

Dennis Barker
Director Sustainable Communities
Surf Coast Shire
PO Box 350
Torquay Victoria 3228
9th February 2010
Our project ref: 1963
Dear Dennis,
Re: Technical peer review the AECOM (2009) Ecological Site Inspection – Torquay
Golf Club report.
Introduction
Background
The Jan Juc Creek is a first order ephemeral creek that is approximately four kilometers
long. The catchment is made up of a combination of urban, semi-urban and rural. The
majority of the creek underground running through a pipe until it reaches Hoylake
Avenue, where the creek is a more natural system. The Torquay Golf Club has applied to
the Surf Coast Shire to harvest stormwater from Jan Juc Creek to assist in the short fall in
water requirements for the Torquay Golf Club. AECOM (2009) conducted an Ecological
Site Inspection to determine if ecological matters will be impacted by the stormwater
harvesting.
Scope of Work
Ecology Partners Pty Ltd was commissioned by Surf Coast Shire to conduct a peer
review on the Ecological Site Inspection – Torquay Golf Club report (AECOM 2009) on
stormwater harvesting of Jan Juc Creek by the RACV Golf Course. The scope of work
included:
•
A review of the AECOM (2009) report methodology and findings, and a review
of the relevant Commonwealth and State aquatic and terrestrial databases;
•
A statement of the likelihood of whether listed threatened species or communities
are likely to be significantly impacted by the proposed works; and,
•
Recommend if further surveys are required.
Other relevant reports which have been undertaken previously for the Torquay Golf Club
are Alluvium (2009) and Aurecon (2009) and were reviewed for this report.
Results
Fish
There are no previous records of fish surveys having been conducted within Jan Juc
Creek. AECOM (2009) does not provide any details on the likelihood of any fish species
occurring within Jan Juc Creek.
It is likely that there will be native fish species present. The creek is likely to include
both migratory and non-migratory species. The species present will depend on the
quality of the habitat and whether the mouth of the creek has been open. Jan Juc Creek
may support species such as Common Jollytail Galaxias maculatus, Tupong
Psuedophritis urvilli, Australian Mudfish Neochanna cleaveri, Short Finned Eel Anguilla
australis, Australian Grayling Prototroctes maraena, Mountain Galaxias Galaxias olidus
and Pygmy Perch Nannoperca australis (DPI 2010).
The likelihood of native fish species occurring with Jan Juc Creek will be dependant on
the quality of the habitat, water quality, flow conditions (frequency and volume) and for
those species that require recruitment via a connection to the ocean, require that the
mouth of the creek has been or is open.
Environmental Assessment
There is little data on the current health of the creek from the reports reviewed. A habitat
assessment should be conducted using either the Index of Stream Condition (DSE 2006)
or the EPA Rapid Bioassessment Habitat proforma (EPA 2003) as a minimum. In
addition a water quality assessment and a macroinvertebrate collection should have been
conducted and the results compared with the State of the Environment and Protection
Policy (Waters of Victoria) (EPA 2003).
Environmental Flows
The creek is a highly modified waterway along the majority of the length of the drainage
line. All stormwater or natural flow is moved underground using a pipeline. The lower
length of Jan Juc Creek downstream of Hoylake Avenue is a natural creek system. There
is little information within the AECOM (2009) or Aurecon (2009) reports which states
the amount of water required within Jan Juc Creek downstream of Hoylake Avenue.
Evidence to support the statement that removing water from the system will result in
flows more comparable to historic flows is not provided.
Further assessment of flows is recommended to determine the minimum requirements to
retain the biodiversity values of Jan Juc Creek (e.g. for wading birds, vegetation, fish
species, etc).
Threatened Species
Without knowledge of the habitat features present within Jan Juc Creek it is difficult to
ascertain the likelihood of threatened species to occur within the waterway. However,
Yarra Pygmy Perch Nannoperca obscura which is nationally listed (under the
Environmental Protection Biodiversity Conservation Act 1999) as vulnerable was
recorded within Thompson Creek at Horseshoe Bend, approximately seven kilometres
from Torquay (AVW 2007). Yarra Pygmy Perch are generally found in areas where
there is a high abundance of aquatic vegetation.
The Australian Mudfish (as highlighted by CCMA 2009), listed as threatened under the
Victorian Flora and Fauna Guarantee Act 1988, are generally found in similar locations
to Yarra Pygmy Perch but prefer wetland and marshy type of environments and are
thought to migrate between oceanic and freshwater environments. There are few
historical records of the Australian Mudfish throughout Victoria generally due to the
rarity of the species. It is a nocturnal active species that is known to be able to aestivate
during drought.
Similarly, Australian Grayling, which is also a nationally listed species, is a migrating
freshwater species with an oceanic stage; are rare throughout Victoria and are found in
coastal drainages. The likelihood of these species occurring depends on whether or not
the mouth of the Jan Juc Creek is open to allow for migration of the species from the
ocean. Stormwater harvesting may reduce the likelihood of the river mouth opening or
the frequency of the mouth being open.
There are three records of Growling Grass Frog Litoria raniformis (AVW 2005) within
10 kilometres of the study area. Their presence within the site is dependant on the
available habitat. Generally the species prefers deep water holes with a mixture of
macrophyte types including, but not limited to, emergent species such as Eleocharis spp.
and floating such as pondweed Potamogeton spp. Without an amphibian habitat
assessment it is difficult to determine the likelihood of the species occurring within Jan
Juc Creek. Further assessments for this species in areas of potentially suitable habitat are
recommended.
Potential Impacts
The AECOM (2009) report examines the impact on vegetation and suggests that the
harvesting of stormwater will actually return the waterway more to historical flows.
Evidence of this is statement is not supported within the report. In general terms,
harvesting water from the Creek and reducing the amount of water within the system may
have the following impacts downstream of Hoylake Avenue:
•
The creek dries up for longer periods. This may also increase the duration for the
mouth of the river remaining closed, which can impact on the recruitment of
oceanic migratory fish species;
•
Reduction of the water available for instream biota;
•
Reduction in the abundance of aquatic plants;
•
Reduced flow regimes can impact on breeding cues. Several native fish (i.e.
Tupong) rely on natural seasonal flow regimes to stimulate spawning and
migration. A loss of seasonal flow as a consequence of high levels of water
extraction from coastal aquatic systems is one of the major environmental impacts
on coastal native fish (Drew 2008);
•
Increased risk of out-competition of native plants by invasive weed species;
•
Reduction in the water quality due to evaporation causing pools to become
stagnant;
•
Reduction in the amount of available habitat for native fauna (e.g. fish,
waterbirds, native rodents);
•
Increased risk of predation on fish species from bird species due to a reduced
water level;
•
Potentially increase in risk of physical impacts such as erosion, bank sloughing
and sedimentation: and,
•
An increase in algal bloom frequency.
Recommendations
It is recommended that the following be undertaken in order to determine the potential
impacts of harvesting water from the Jan Juc Creek:
•
A fish survey by a qualified fish biologist within the creek, especially downstream
of Hoylake Avenue, to provide a list of taxa that inhabit the creek and more
accurately determine the potential impacts. The Corangamite Catchment
Management Authority (CCMA) has provided a letter to the Surf Coast Shire
(dated 8 January 2010) recommending an environmental assessment for
Australian Mudfish to determine potential impacts. A habitat assessment should
also be conducted simultaneously to determine the likelihood of other species
occurring in the event that they are not recorded during the proposed survey;
•
A frog survey including an amphibian habitat assessment to determine the frog
species that occur, or may occur within the waterway;
•
An instream health assessment using a combination of macroinvertebrates and
water quality and comparing results to the State of the Environment Protection
Policy (Waters of Victoria) (EPA 2003);
•
A habitat assessment of the creek downstream of the offtake using a standard
proforma such as the Index of Stream Condition (DSE 2006) or Rapid
Bioassessment Habitat proforma (EPA 2003b); and,
•
An environmental flow assessment should be considered using the ‘Statewide
Method for Determining Environmental Water Requirements in Victoria’ (DNRE
2002).
Conclusion
The review of the AECOM (2009) report identified that impacts on threatened fauna, the
effects of environmental flows and the current health of the creek were not assessed
adequately. It is considered that additional environmental assessments are required to
gain more comprehensive understanding of the potential impacts of stormwater
harvesting on ecological values present within Jan Juc Creek.
Yours sincerely,
Cameron Amos
Senior Aquatic Ecologist
Ecology Partners Pty Ltd
P: 0399401411
E: [email protected]
References
AECOM 2009. Ecological Site Inspection – Torquay Golf Club. Report to Royal
Automobile Club of Victoria.
Alluvium 2009. Impact on Jan Juc Creek and its estuary from stormwater reuse. Report
to Royal Automobile Club of Victoria.
AVW 2007.
Melbourne.
Atlas of Victorian Wildlife.
Viridians Biological Databases Pty Ltd,
Aurecon 2009. Stormwater Harvesting Proposal Torquay Golf Club Redevelopment
Royal Automobile Club of Victoria. Report to Royal Automobile Club of Victoria.
Corangamite Catchment Management Authority 2009. Stormwater Harvesting Proposal
Jan Juc Creek. Letter to Surf Coast Shire Dated 8/1/2010.
Department of Natural Resources and Environment 2002. FLOWS – a method for
determining environmental water requirements in Victoria. Catchment and Water
Division, Department of Natural Resources and Environment, East Melbourne.
Department of Primary Industry 2010
Otway/Basin%20TEMPLATE%20Waters.htm).
http://www.dpi.vic.gov.au/angling/35-
Department of Sustainability and Environment 2006. Index of Stream Condition
User’s Manual (2nd edition). Published by the Victorian Government Department of
Sustainability and Environment Melbourne, March 2006.
Drew, M. M. 2008. A guide to the management of native fish: Victorian coastal rivers,
estuaries and wetlands. Department of Sustainability and Environment and Corangamite
Catchment Management Authority, Victoria.
Environment Protection Authority 2003a. State Environment Protection Policy (Waters
of Victoria). Published by the Victorian Government Melbourne, March 2006
Environment Protection Authority 2003b. Guideline for Environment Management Rapid
Bioassessment Methodology for Rivers and Streams. Publication 604.1. EPA Victoria,
Southbank, Victoria.