Bird is the word at the Western Treatment Plant in Werribee.

In the coming weeks, tens of thousands of migratory birds will flock to the plant.

The Melbourne Water site is a magnet for birds due to the variety of the wetlands, the permanent, nutrient-rich water supply and the relative quiet of the site.

With 284 different bird species recorded, hailing from south-eastern Australia, New Zealand and eastern Asia, the plant is one of the nation’s most popular birdwatching spots.

Melbourne Water’s principal biodiversity scientist, William Steele, said that now is a good time for birdwatchers, also known as ‘twitchers’, to visit the Western Treatment Plant and its shoreline, to see thousands of migratory shorebirds foraging over mudflats and waterfowl on the lagoons.

“Some of the migratory species, like the red-necked stint, sharp-tailed sandpiper and curlew sandpiper, fly around 12,000 kilometres from their breeding grounds up in Siberia to enjoy the unique conditions we have at the treatment plant,” Dr Steele said.

“Migratory shorebirds need shallow intertidal mudflats or our managed habitat ponds to feed as efficiently as possible, and they need quiet roosting areas where they can rest safe from disturbance.

“The migration of so many birds from so far away is quite remarkable and we encourage the public to take any opportunity to visit the site.”

Anyone wanting to birdwatch at the Western Treatment Plant must first apply for a permit via melbournewater.com.au.