The health of the Merri - a journey into which future?

In twenty years’, time, what kind of Merri Creek will we hand on to our children and grandchildren? The answer to that question is – well, it depends, on the decisions we make now.

On 6 November 2022, a busload of Friends of Merri Creek ventured along the length to see how different planning outcomes result in vastly different impacts on the Creek.

First stop: ngarri djarrang, otherwise known as the Central Creek Grassland, Davidson St Reservoir. There, amidst the chocolate lilies and the kangaroo grass, we got a look at the fabulous work done by Merri Creek Management Committee, with some assistance from Friends volunteers, in restoring an indigenous grassland. But we also saw how an invasive species, the South African weed orchid, is virtually impossible to eradicate, first because weeding efforts were suspended during the COVID lockdowns, and second because – like many Australian plants – this interloper is adapted to live in fire conditions, so even ecological burning doesn’t help. Undaunted, Michael explained the complex work he is leading to re-introduce further local species, including Swamp Everlasting, Plains Yam Daisy and Basalt Daisy. These rare plants are now establishing successfully in the grassland, despite challenges posed by changed hydrology, introduced snails and unreliability of normal planting methods.

   

Plants from ngarri djarrang: Scented sun orchid, Blushing bindweed

Next stop: bababi marning, the grasslands conservation reserve at Cooper Street Campbellfield. There we saw the challenge in containing another invasive species – gorse – which again is fire resistant and requires other forms of control. This task has recently been made more difficult for the Friends’ ‘Woody Weed Whackers’, led for many years by the indomitable Ray Rayford, thanks to Parks Victoria’s new and burdensome requirements for all volunteers on Parks-managed land. So, conservation management will require further public spending, which has been promised by most of the candidates in the State election – we shall see. What we undoubtedly did see at bababi marning was a mob of grey kangaroos, and what a remarkable gift we have to see this magnificent wildlife within 17 kilometres from the centre of a global city like Melbourne.

And so, onto the Golden Sun Moth playground and park on Malcolm Creek, a Merri tributary at Craigieburn. Named for the vulnerable moth that only lives for two days (it lacks a mouth with which to feed), the playground is ordained by ancient river red gums, another reminder of the majesty of the ecosystems along the Merri. 

Our next stop was a depressing one, at Whiteleaf Drive, Merrifield/Mickleham. There we saw a ‘constructed waterway’ and MCMC’s Manager Luisa Macmillan explained how this ‘engineering’ is an erosive calamity in so-called sodic soils – these are soils so fine that once wet, they simply disperse. It is the runoff from these soils, disturbed by housing subdivisions, that are responsible for the turbidity (muddiness) of the Creek downstream after rainfall. The multiple failure of the developer’s engineering at Merrifield is such that Melbourne Water has refused to take on ownership of the ‘waterway’ – and we’re still waiting for a solution to the obvious and damaging erosion at the site.

Whiteleaf Drive, Merrifield/Mickleham

At Green Hill, Wallan we met a good Friend – Rob Eldridge, Councillor of Mitchell Shire and member of our affiliated organisation, the Wallan Environment Group. From the panoramic view from the summit, we saw the (possibly) good, the bad and the downright ugly. Rob explained his vision for the wallan wallan regional parkland, to include volcanic cones like Mount Fraser, and the remnant wetlands of Herne Swamp and burrung buluk. These wetlands could yet be preserved and repaired – but not if subdivisions like the aptly named Wallara Waters continue. Built on part of the Herne Swamp – at a time when the Federal Government is considering buybacks of flood prone properties elsewhere (go figure) – this subdivision is literally surrounded by water in any reasonable rainfall, and yet again, ‘engineered’ waterways pour millions of litres of water into the Merri at flow rates too high for the aquatic ecosystem to cope with. There’s still time to do better, but the wallan wallan Regional Park is critical to preventing further harm to the Creek.

 

Herne Swamp and the future Wallan Regional Park from Green Hill.

And finally, onto the Hidden Valley Rail Reserve, at the very headwaters of the Merri. There we saw a remarkable difference – between the monoculture of grazed farmland, separated by a wire fence from a thin railway easement, never grazed, and as a result, still resplendent with flowering indigenous wild flowers. These included Button Everlasting, Milkmaids and Golden Moth Orchids and many more – listed at the end of this article. On hand to talk about this wonderful oasis were WEG members Norbert Ryan and Gerry Wun Ho, dedicated local activists working to protect the reserve and take it under volunteer management from the railway authorities. 

       

Button everlasting, Coronodium scorpioides at the Hidden Valley Rail Reserve

And the take away from this terrific day? Too many of the reserves along the Creek – such as at ngarri djarrang, bababi marning and Hidden Valley, are planning ‘accidents’, which the community was on hand to fight for and preserve. Ngarri djarrang and bababi marning were earmarked for freeway development, and when the community won the battle to defeat this, there were campaigns to secure the land for conservation purposes. At Hidden Valley, the reserve is a ‘leftover’ from a disused rail line. In contrast, where official planning decisions have had their way, the result has been environmental disaster, at Merrifield and Herne Swamp.

We have the chance to do better, by making conscious decisions that benefit the Creek. The declaration of the marram baba Merri Creek Regional Parkland (in the middle reaches of the Creek north of the Ring Road) and the wallan wallan Regional Park (in the upper reaches) are an opportunity for us to put right the many wrongs we have inflicted on the Merri Creek.

We can do this – if our governments can find the political will, and if they won’t - we have to find it for them.        

Plants on Hidden Valley unused rail reserve

Arthropodium strictum, Chocolate Lily

Brunonia australis, Blue Pin-cushion

Burchardia umbellata, Milkmaid 

Coronidium scorpioides, Button Everlasting

Dillwynia cinerascens, Grey Parrot-pea

DIllwynia sericea, Showy Parrot-pea

Lomandra longifolia, Spiny-headed Mat-rush

Lomandra filiformis, Wattle Mat-rush

Pimelea humilis, Common Rice-flower

Acrotriche serrulata, Honey-pots

Leucopogon virgatus, Common Beard-heath

Acacia aculeatissima, Thin-leaf Wattle (also Snake Wattle)

Diuris chryseopsis, Golden Moth Orchid

Platylobium montanum, Hill Flat-pea (formerly Platylobium formosum)

Dianella revoluta, Blue Flax-lily

Rytidosperma pallidum, Silver-top Wallaby-grass (formerly Joycea pallida)

Eucalyptus obliqua, Messmate Stringybark

Eucalyptus dives, Broad-leaved Peppermint 

Image credits: Ann McGregor.