Yarra Catchment Snapshot
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Yarra Catchment Snapshot 1. Overview of catchment 2. Highlights of the catchment – natural values 3. Good wins (programs/projects) 4. Key Issues Tuesday 10 October 2017 Overview of Catchment Whittlesea 2 Yarra Catchment ~ 4000 km Craigieburn Yarra Glen Headwaters of the Yarra in the Yarra Healesville Warrandyte Ranges National Park Warburton Flows ~250km via Melbourne into Port Melbourne Phillip Major waterways include: Monbulk Port Phillip Merri Creek Darebin Creek Plenty River Diamond Creek Watsons Creek Watts River Woori Yallock Creek Brushy Creek Mullum Mullum Creek Olinda Creek Pauls Creek Steels Creek Stringybark Creek Gardiners Creek Koonung Creek River HealthEarly Yarra Monitoring • Robert Hoddle ‘Surveyor in Charge’, surveys of River in 1830s-40s: ‘ Water is excellent in the River Yarra Yarra… (and as far up as the Plenty)… the Yarra continues a fine full stream of clear water in places bubbling over ledges of rock, at others forming fine deep reaches… it is perhaps the finest river I have seen in New South Wales…. The Yarra abounds in fine fish and the water is of very good quality.’ • Garryowen (Chronicles of Early Melbourne) Banks of Yarra to Maribyrnong confluence as ‘ low marshy flats, densely garbed with teatree, reeds, sedge and scrub. Large trees, like lines of foliaged sentinels, guarded both sides and their branches protruded so far riverwise as to more than half shadow the stream’. RiverHistorical Health ImpactsMonitoring Extensive modification of the Yarra catchment and its waterways – Vegetation clearing – Floodplain drainage – Channel realignment/widening/ piping e.g. 1880-90s Coode Channel 1880s Draining West Melb Swamp Docklands (2nd largest in world) Queens Bridge rock falls removed Realignment adjacent to Botanic Gardens – De-snagging (24,000 1924-30) – Water extraction/catchment protection – Urban/Industrial development – Billabongs/wetlands as tip sites Gardiners Creek 1985 RiverHistorical Health ImpactsMonitoring • Picturesque Atlas of Australasia, during 1880s ‘Nothing can be more…. repulsive, than the approach to Melbourne by the river Yarra… polluted with the drainage and sewage of the city and of half a dozen suburbs, [it] is as offensive to the eye as to the sense of smell.. Aggravated by the fumes of various noxious industries that have been established on the banks’. • Otto (1840s) ‘…there where thousands of tonnes of blood and guts were dumped annually to float, putrefying, in the river along with dead cattle and the outpourings of live ones. There were slaughterhouses or abattoirs, along with every conceivable sidebar business, up to Dight’s Falls’. Water taken from the Pumps on the lower Yarra at one point was described as ‘having the consistency of very weak gelatine.’ ‘in a town of hundreds of thousands of people with no sewerage system or stormwater drainage, just open gutters that ran like tiny creeks of nightmare, picking up dunny overflows including infected matter; dirtied kitchen, laundry and bath water; guts dropped out of backyard-slaughtered sheep; tonnes of horse dung and tonnes of silt from the unmade roads of Melbourne.. All of it went swirling and blobbing into the river’. • 1970s Prince Charles was reported as refering to the lower Yarra ‘… one of the dirtiest streams I have ever seen.’ HistoricalRiver Health Improvements Monitoring 1890s Melbourne’s residents gradually sewered 1970s Environment Protection Act 1980s minor wastewater treatment plants established to replace septics Mostly diverted to major treatment plants, but some remain e.g. Olinda and Brushy Creeks. 1990s management of waterways for ecological health Forested Areas ~21% Agriculture ~57% Urban ~ 22% Catchment – Environmental Values Environmental Values: Environmental values • Birds • Fish • Frogs • Macroinvertebrates (water bugs) Environmental conditions • Platypus • Vegetation Aquatic macroinvertebrates Photos by John Gooderham and Edward Tsyrlin Environmental Values – Macroinvertebrates Based on aquatic macroinvertebrate community surveys since 1990s and modelled predictions (‘LuMAR’ score) Stream health highest along main stem and in the middle and upper catchments Threats: - Urban stormwater primary impact on invertebrate communities (water quality and flow) - Loss of instream and riparian habitat (vegetation, physical form) - Agricultural and industrial pollution - Loss of stream flows – extraction, climate change Environmental Values – Fish • Mainstem of the Yarra very important • 14 indigenous freshwater species, including nationally significant Australian grayling, Australian mudfish • Several estuarine species e.g black bream, yellow eye mullet, mulloway • Introduced native fish e.g. nationally significant Macquarie perch, Murray cod • 10 exotic species e.g. brown trout, carp, redfin, goldfish, mosquitofish, roach • Freshwater crayfish Photos by Tarmo Raadik Native Fish Photo by Neil Armstrong Photo by John McGuckin Photo by John McGuckin Environmental Values – Fish Threats to fish species include: • habitat loss/degradation (instream and floodplain) • several large barriers to movement in the catchment • urban stormwater • Agricultural/industrial pollution • pest fish • changes in natural stream flows Photo by Tarmo Raadik Environmental Values – Frogs Fifteen species of frog are expected to occur in the Yarra catchment Frog condition scores range from ‘High’ to ‘Low’ <40 frog records for many areas over past 5 years = no frog condition rating Threatened Frogs The nationally listed Growling Grass Frog still occurs in some sub-catchments, mostly north-western tributaries e.g. Merri and Darebin Creeks Growling grass frog Other threatened species: Nationally listed (Vulnerable) Bibron’s Toadlet (Endangered in Victoria) Southern Toadlet (Vulnerable in Victoria) Our last records of these species were in 2010 and 2014 respectively Southern toadlet Common Spadefoot Toad also not State advisory listed (Vulnerable) recorded in our region in last 5 years Photos by Peter Robertson Common Frogs Southern brown tree frog Striped marsh frog Common froglet Banjo/Pobblebonk frog Spotted marsh frog Photos by Peter Robertson Catchment - Environmental Values – Platypus • Upper catchment and mainstem of Yarra important for platypus, but occur in many areas • Declines evident in many populations across the region, thought to be largely drought related • Some recovery since, but apparent losses in fragmented populations e.g. upper Plenty River Catchment - Environmental Values – Platypus Threats include: - urban stormwater (litter, loss of food) - loss of riparian vegetation - loss of instream habitat, low flow refuges - Fragmentation/inbreeding - Changes in stream flows Lower Plenty Plenty Gorge Lower Diamond Olinda Creek Mullum Mullum Warburton Environmental Values – Birds Important bird habitats, including Yarra estuary, billabongs, extensive streamside vegetation and forested headwaters. Sub-catchments score from ‘Very High’ to ‘Low’ for riparian birds. Insufficient data to calculate a riparian bird community metric for half of the areas. Developing a condition score for wetland birds Environmental Values – Riparian & wetland birds 252 bird species have been recorded in the catchment. White-bellied Sea-Eagle Australasian Bittern The ‘expected’ list of streamside birds is (John Barkla, Birdlife Australia) larger than for any other catchment with 153 species, ranging from Little Grassbird and White-browed Scrubwren to the iconic Laughing Kookaburra, Superb Lyrebird and White-bellied Sea-Eagle. Blue-billed Duck (John Barkla, Birdlife Australia) Chestnut Teal (John Barkla, Birdlife Australia) Species listed as nationally threatened include Swift Parrot and Australasian Bittern and Helmeted Honeyeater Lathams’ Snipe (Geoff Gates) Barking Owl Environmental Values – Vegetation • Largest and most intact area of vegetation are forested headwaters e.g. Yarra Ranges NP Map under preparation • Support many rare and threatened plant species (e.g. Jungle bristle fern, tall Astelia, tree geebung) and old growth mountain ash (e.g. O’Shannassy) • Extensive land clearing has resulted in riparian vegetation being in very low to moderate condition in many areas • Pest plants and animals an ongoing threat e.g. blackberry, willows, red cestrum (Watts River), sambar deer • Extensive riparian revegetation effort by many groups and organisations has led to substantial improvements Environmental Values – Vegetation Some notable high value vegetation areas include: Yellingbo Nature Conservation Reserve: contains Cockatoo Creek swamp and sedge rich Eucalyptus camphora vegetation community (FFG listed), also supports threatened Leadbeaters Possum and Helmeted honeyeater Yering Backswamp (Christmas Hills): supports a diverse mix of species including Giant Rush, Australian Basket-grass rare in the Yarra catchment. Bolin Bolin Billabong (Bulleen): important culturally and also supports pre-European arrival remnant red gums Yarra Bend Park: good example of floodplain riparian woodland vegetation community close to the city. Yering Gorge and surrounds: home to a range of vegetation types including drier grassy woodlands, box- ironbark forest, and native orchids. Also a critical biolink along Watsons creek towards Kinglake NP. Warrandyte State Park and surrounds: riparian vegetation in excellent condition Spadonis Nature Conservation Reserve (Yering): population of the rare Buxton Gum Wilsons Reserve (Ivanhoe): another good example of floodplain riparian woodland, including habitat for rare species such as powerful owl. Cultural Heritage •