Water Worx interview: Matěj Ostárek, Štěrkovna Open Music

In 2024, the Štěrkovna Open Music event was ranked among the top ten small-scale European festivals. The festival, which Matěj Ostárek organizes with his team in his spare time, takes place in the unique setting of the Hlučín swimming pool. How does this unique location influence the execution of the event itself? What makes Štěrkovna unique, in his opinion? What was the advantage of getting engaged in front of thousands of people at a Tomáš Klus concert? And where do he and his team draw their inspiration from? You’ll find that and much more in the interview below.

To start off, I’d like to ask you to introduce yourself to those who don’t know you. Who are you, and what kind of event do you organize?

My name is Matěj Ostárek, and together with David Moravec, we organize the Štěrkovna Open Music festival, which takes place every year at the end of July in Hlučín. It’s a medium-sized festival attracting thousands of music fans each day. We’re the third-largest festival in the Moravian-Silesian Region. This year, 2025, marked the festival’s 21st edition. Since 2018, we’ve been organizing the festival at its current scale—that is, for thousands of people every day of the event.

What makes your festival unique?

The event takes place in a beautiful lakeside setting at Hlučín Lake. Our lineup features mainly Czech artists and bands. We always strive to create special and extraordinary musical experiences that visitors won’t find anywhere else—they can only hear them here.

Can you be more specific?

For example, we came up with the Symphonic Dance Music project, a collaboration between the Janáček Philharmonic Orchestra Ostrava, DJ Lowa, and a band. Together, they perform a 90-minute DJ set that premiered in 2019. We reprised this show in 2024. Add to that the lasers, the lighting effects… I got goosebumps. We told ourselves, this makes sense, this is really awesome.

From a production standpoint, how has the Štěrkovna Open Music event changed from its early years to today?

It’s gone from an amateur event that people just put together in the evenings to a professional event that people put together in the evenings. (laughs) It’s important to note that we’re a team whose core consists of four people. During the year, we have our own jobs and other work, and organizing the festival is a hobby for us. Thanks to our vendors and the dedication of others, we’re able to put on a top-quality event.

You mentioned that a team of four people spends the year preparing for the festival. How many of you are there at the event itself?

Hundreds. I calculated that our payroll shows about 12,800 paid hours, which translates to roughly seven full-time positions during the event that we pay directly.

How has Štěrkovna changed since COVID? Was COVID a turning point for organizing an event of your type?

Paradoxically, it helped us a lot. Since we have our own jobs, we weren’t financially dependent on income from organizing cultural events. After the pandemic, we started thinking differently. We had to move to different and alternative venues. When we returned to the Hlučín gravel pit in 2023, we viewed the site in a completely different light. We rebuilt it differently; we overhauled the foundations. That was the impetus to do things differently and better.

Costs—not just for organizing social events—are generally rising. How has that affected production and event preparation in general?

A lot. It’s important to note that when I compared the budgets from 2018 versus 2025, even though the venue’s capacity didn’t increase, our budget tripled. You can really feel the impact of inflation there. The second thing is that the number of staff required to run the venue has grown. Fortunately, we were able to avoid passing that cost on to ticket prices. And because we have good partners, we were able to cover the costs through sponsorship. So, I can knock on wood and say that every cloud has a silver lining. The bottom line is that everything is more expensive, and we have to look for funding more intensively and in other places.

Do you have any festival role models? Any events that inspire you?

Last year, we made it into the top 10 small European festivals. This year, we hope to climb even higher. We’ll see—keep your fingers crossed for us. But if you’re asking about role models, we started with events in our own country, like Beats for Love or Colours. We also looked at Rock for People. Every event has its own specific atmosphere. When we look abroad, I really like the Grape Festival. The way they work with the space and the visitors there. That’s a huge inspiration for me—a beautiful brand, hats off to them. We’d like to build something like that here.

That brings me to the question: where do you want to take Štěrkovna?

We want to be the best European event in our category and size. And we want to be a beautiful, branded event that people will love to attend. We’d also like to sell out our festival by Christmas.
Sustainability at large events is a very timely topic right now.
Sustainability is also one of our main priorities. That’s partly why we turned to Waterworx. We didn’t want chemical toilets anymore. We wanted to solve the water management issue in a way that made ecological sense.

What was your initial brief for Waterworx?

We are located at a swimming pool complex with two sewer connections, and we needed to set up the infrastructure so that we could place the restroom facilities in the ideal locations on the grounds. We also needed to figure out how to connect the wastewater to the sewer system and supply drinking water to the portable toilets. In 2025, at our festival, we had only ceramic flush toilets for all visitors, including in the backstage areas—no chemical toilets.

Will visitors notice this in the ticket price?

We want our visitors to be accustomed to a certain level of comfort and not notice it in the ticket price. With us, they simply get the best quality in this regard.

Should visitors be able to tell that they’re at a festival focused on sustainable production?

In my opinion, sustainability is all about the visitor not even noticing that the event focuses on sustainability. It shouldn’t restrict them in any way. At the same time, in my view, it should be a given for organizers. We’re very open about it ourselves; our approach to sustainability, including the measures we take, is publicly available on our website.

If you look back on the past, what’s your favorite memory of Štěrkovna?

My favorite memory was in 2018, when I got engaged during a concert by Tomáš Klus (who was performing with the Janáček Philharmonic Orchestra Ostrava). The whole family from both sides was there, along with several thousand other people. The advantage was that we didn’t have to tell anyone about it afterward. But otherwise, the Hlučín Lake area has an amazing genius loci. When the water is calm and the sunset sets in… It’s a beautiful sight, and you get a nice sense of fulfillment.

You mention that your venue is a unique space. But the body of water on the grounds must certainly have specific production requirements. How do you deal with that?

On one side of the grounds, we’re limited by the aforementioned body of water; on the other side, by a fence; and then by the very nature of the place—it’s a public swimming pool that operates in the summer. We have to balance that with the festival’s needs and vice versa. We can’t restrict those who go there all season long. And from a safety perspective, we naturally work with lifeguards to prevent injuries or even drownings. I have to knock on wood—in all these years, no one has drowned. We have to maintain the lake in such a condition that the locals like us. Most of the staff at the event are locals, and we also care about the people of Hlučín enjoying the event. Which they do—it’s the top event of the summer for them.