Black Diamond Lake, Allanson

Black Diamond Lake near Collie has become one of WA’s most famous “Insta lakes” thanks to its surreal turquoise water and forested surrounds. Once an open cut mine, it’s now a beautiful pit lake that makes a fun day trip for families willing to do a bit of planning and pack everything they need.

Located in Allanson, about 5km west of Collie and roughly two hours’ drive from Perth, Black Diamond Lake is just off Coalfields Highway on Ferguson Road. The lake’s dazzling blue colour comes from the limestone in the water and is at its brightest on sunny days, so it’s worth checking the forecast and aiming for clear skies if you want those wow-factor photos.

A visit here is all about simple fun by the water. Families set up along the foreshore with picnic rugs, camp chairs and shade, then spend the day swimming, paddling and floating about on inflatables, stand-up paddleboards and kayaks. The lake is deep, cold and incredibly clear, so older kids and teens love jumping in, while younger ones tend to splash along the shallower shoreline areas. Even if you don’t get in the water, it’s a stunning spot to relax, take photos and enjoy a picnic.

Black Diamond Lake has a long, spread-out foreshore with multiple little pockets where you can pull up for the day. On busy summer weekends and holidays it can get very crowded, and the most popular spots closest to the main car parking fill quickly. Arriving early gives you a better chance of parking close to the water and snagging a shady area. The car parking is on unsealed ground and can be uneven with puddles after rain, but you don’t need a 4WD – just take it slowly in a low-clearance car and pick your line carefully.

There are no permanent facilities at the lake and no potable water. Different sources note that there are either no toilets or, at best, occasional portable toilets during peak season, so you must visit prepared to be fully self-sufficient with drinking water, food, shade and rubbish bags, and you should not rely on toilets being available all year round. There are no rubbish services along the shore, so everything you bring in must go home with you.

Because Black Diamond Lake is a former mine, there are some important safety and comfort points for families. The lake can have submerged trees and other underwater hazards, and the edges in some spots are rocky or drop away quickly, while other stretches have more gentle “beach-like” shorelines that suit younger kids. The water is very deep and can be acidic compared with normal freshwater lakes, which may irritate sensitive skin, and it’s usually icy cold even in hot weather. Like other inland water bodies, there can be periods where harmful organisms such as amoeba are present; local authorities advise keeping your head above water and avoiding getting water up your nose, and to check the most recent water quality updates with the Shire of Collie before swimming. There may also be signage at the site indicating when bacteria levels are high.

On land, broken glass and other litter can be an issue in some areas, so it’s wise to have kids wear sandals or thongs and to give your chosen patch of ground a quick scan before setting up. You’ll also want something comfy to sit on, as the ground can be hard and dusty. In summer, shade along the water’s edge disappears fast, so bringing your own gazebo or beach shelter is almost essential for families planning to stay several hours.

Despite those cautions, Black Diamond Lake can be a fantastic, memorable day out. There’s a friendly, relaxed vibe on busy days, with plenty of other families around, and because the foreshore is quite long it still feels spacious even when the car park is overflowing. It’s easy to spend most of the day here swimming, floating and picnicking, then pack up and drive the short distance into Collie for an ice cream, café lunch or an early dinner. With the rapid growth of tourism around Collie, many families also combine a visit to Black Diamond with other attractions such as Wellington Dam and its huge mural, Potters Gorge, Lake Kepwari or Honeymoon Pool, making a full weekend of it.

Black Diamond Lake is strictly day use only. There is no camping or campfires allowed along the shores, and local rangers patrol regularly, issuing on-the-spot fines to anyone ignoring the rules. If you’d like to stay nearby, there are multiple excellent family-friendly options, from campgrounds such as Stockton Lake, Honeymoon Pool, Gelcoat Rapids and Potters Gorge to caravan parks and motels in Collie itself. Many families find it easier to book a night or two so they can explore the broader Collie River Valley without having to rush.

For families who are prepared, Black Diamond Lake really does live up to the hype. It’s a spectacular setting for a day in and by the water, a brilliant backdrop for photos and a great base for discovering everything the Collie region now offers. Just be sure to plan ahead for facilities, follow all safety advice, keep a very close eye on children in and around the deep water, and leave no trace so this beautiful but fragile site can continue to be enjoyed for years to come.

Black Diamond Lake

Address: LOT 85 Ferguson Road, Allanson WA 6225 (about 5km west of Collie, just off Coalfields Highway)
Opening hours: Day use only; no camping or overnight stays permitted
Official information: Shire of Collie – Black Diamond public notice

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