Swimmers warned to be careful at Black Diamond Lake

The sparkling blue waters of Black Diamond Lake in WA are attracting swarms of tourists.

It’s one of Australia’s finest natural swimming holes but it’s got a secret past that means swimmers dive in at their own risk.

Black Diamond Lake is an abandoned coal mine. It is a two-hour drive southwest of Perth and five kilometres north of the mining town of Collie.

Do you believe this was once a coal mine? @emmajaneleeson

After it was decommissioned in the 1950s, the Black Diamond Coal Mine flooded with water.

Now, its turquoise-blue waters are the backdrop of thousands of visitor Instagram posts.

And it’s now a popular tourist attraction for WA travellers who can’t venture outside of their state due to border closures.

How dangerous is it really?

You can swim in Black Diamond Lake but signs warn of dangerous levels of bacteria. Authorities say if you do take a dip, you do so at your own risk and should keep your head above water.

If you want to be on the safe side you are encouraged to call the Collie Shire to find out any information about the most recent water tests.

As far as any more danger is concerned, you should keep your eyes peeled for bull ants when you set up to have a picnic lunch.

Black Diamond lake has become popular for kayaking, canoeing and standup paddleboarding.

Camping at the site is a big no-no, but Stockton Lake is just eight kilometres east of Collie. There you will find camping amenities including toilets, picnic and barbecue facilities.

We don’t know exactly what makes Black Diamond Lake such an intense shade of blue but scientists believe it is the result of sunlight reflecting off limestone rock on what was once the coal mine floor.

Many van trippers and travel bloggers have taken a liking to the lake’s azure waters including travelling couple Emma and Thom Shaw of Explore Shaw.