Why Does Currimundi Lake Keep Opening and Closing?

If you’ve spent much time around Currimundi Lake, you’ve probably noticed the entrance has a mind of its own.

One week there’s water flowing out to the ocean. Another week, you come down and there’s a stretch of sand right across the mouth.

It’s something locals are pretty familiar with, but not everyone knows why it happens.

And there’s actually a bit more to it than you might think.

So, why does the lake close?

Currimundi Lake is what’s known as an intermittently open and closed coastal lake.

Basically, waves and tides gradually push sand into the entrance. Over time, enough sand can build up to close the lake off from the ocean.

Then, when we get some decent rain and the water level rises, the lake can naturally break through that sand and open up again.

There’s no set timetable. Sometimes the entrance stays open for a while, and other times it closes fairly quickly.

That’s why the Currimundi Lake mouth can look completely different from one visit to the next.

Why doesn’t Council just keep it open?

This is probably the part that surprises people.

Council doesn’t automatically bring in an excavator every time the entrance closes.

The opening and closing is a natural part of how the lake works, and Council generally allows that process to happen.

There are circumstances where they can step in, particularly when rising water levels create a risk of flooding further upstream.

But deciding when to open it involves more than simply looking at the sandbar. Council considers things like rainfall, tides, water levels and the conditions at the entrance.

And a closed entrance doesn’t automatically mean the water quality is poor.

Not every closure is natural, either. Council can also rebuild the sandbar to protect nearby infrastructure or help control midges. Its Currimundi Lake management information explains the different types of work.

There’s more to the lake than you can see from the beach

Something else worth knowing is that Currimundi Lake is connected to a much larger waterway system.

The lake connects with Currimundi Creek and the Wurtulla canals, which also link through to Lake Kawana.

So when you’re standing at Currimundi Beach looking towards the lake entrance, you’re only seeing one part of the system.

It’s also why changes to water levels can affect areas well beyond the beach.

One of those things you notice when you live here

I reckon these are the sorts of things that make getting to know a neighbourhood interesting.

You can walk past the same place for years without necessarily knowing much about how it works.

Currimundi Lake is a good example.

Whether you’re heading down for a walk, taking the kids for a paddle or just enjoying some time beside the water, it’s worth knowing a little about the place.

And next time you come down and find the entrance closed over with sand, you’ll know a little more about what might be happening.

There is a human history beside the water, too. Our story about Currimundi’s old beach houses looks back at the family holidays, simple homes and memories that connect people to this part of the coast.

Before swimming or paddling, check current advice and conditions. Stay well clear of machinery and strong currents during lake-opening works.

Mitch Lund | ELITE Lifestyle Properties