Media Release: Melbourne's Rivers Benefit From Heavy Rain

22 October 2009

SIGNS OF NEW LIFE IN RIVERS AFTER HEAVY RAIN

* Highest spring flows since 2004 a lifeline for stressed ecosystems
* Best breeding conditions in five years
* Population of water-based animals expected to jump

Melbourne's waterways are expected to have a new lease on life after recent rain, as rivers like the Yarra, Maribyrnong and Werribee experience some of their highest spring levels for five years.

Continual monitoring by Melbourne Water, which manages the health of 9,000km of rivers and creeks across the metro area and beyond, tracks the impact of drought and heavy rain on stressed ecosystems.

Manager of Waterways, Chris Chesterfield, said animals like platypus, native fish and frogs were expected to flourish on the back of higher flows.

"Because of drought and the need to boost urban water supplies, our waterways have been doing it particularly tough for the past five years, and we know it's had an impact on the animals that live in them," said Mr Chesterfield.

"Minor floods are a critical part of river ecology. They trigger fish to spawn, flush sediment and carve out new ponds and habitats. These are some of the best breeding conditions we've seen in the Yarra in nearly five years.

"People should be able to notice this by simply listening to the increased chorus of frogs at their local wetland or waterway.

"The water levels themselves are temporary, but the wash up from an event like this will ensure the survival of many more animals through the summer.

Higher flows will improve water quality by increasing dissolved oxygen levels and lowering water temperature and salinity, which significantly enhances conditions for wildlife. Some of the key benefits are expected to be:
* Create opportunities for spawning and migration of native fish, including threatened species like Macquarie perch and Dwarf Galaxias.
* Refresh low-lying floodplains and billabongs, especially in areas like the Yarra and Dandenong Valleys.
* Improve breeding conditions for platypus, frogs and waterbirds.

Mr Chesterfield said that while upper sections of waterways would thrive, lower sections in urban areas would confront increased stormwater pollution after storms.

"Any time there is heavy rain, we see a temporary spike in pollution downstream of built-up areas. That's because stormwater picks up all the impurities on roads and pavements, and literally washes them into our rivers.

"Lots is being done by Melbourne Water, EPA Victoria and local councils to clean up stormwater before it gets into suburban creeks. We've seen baseline levels stabilise in recent years, despite the amount of new development in Melbourne.

"Everyone can help reduce stormwater pollution by picking up after their dog, making sure their car isn't leaking oil and properly disposing of household chemicals like paint."

Media contact:
Nicolas McGay,
(03) 9235 2278;
0438 981 836

SOURCE: Melbourne Water