Munich's Surfers Left Stunned After Famed River Wave Vanishes

The first time I saw them was around Christmastime and I was just stunned by the sight of surfers in the middle of a snow-filled park.

I know it’s a technicality, but the wave is at the very beginning of the park. Not the middle. I can very much recommend walking at least until the lake, if you happen to be visiting Munich. That would be about 1 third of the park.

Why don't you think they'll be able to restore it? Manmade standing waves are common (and the Eisbach was manmade in the first place.)

That’s what they did and that broke the wave.

As you read in the article, yes, they did, and that's what caused the problem.

> Have they tried turning it off and back on again?

Yes, but the bloody thing updated itself between reboots. But, don't worry, Microsoft will release a fix in a couple of years.

The forced update bricked the wave :(

Yes. Techniker ist informiert.

According to other sources (German: https://muenchen.t-online.de/region/muenchen/id_100983050/mu...) some experienced surfers also say that the water level has been unusually low since the reopening (1.40 m and has since dropped to 1.21 m instead of the usual 1.50 m), which of course influences the flow. So some issue with the weirs regulating the flow is suspected - if it's "only" this, it might be quick to fix...

It could be that, yes.

This is classic turbulent/laminar behaviour, driven by Reynolds number - the volume, the flow rate, the shape of the vessel.

I actually did a hydrodynamics project around this 20 odd years ago as a first year undergrad - one thing I noted was that I had to open valves slowly - any sudden acceleration could dramatically alter the threshold at which one would transition from laminar to turbulent flow, and you could only get back to the laminar regime by entirely stopping the flow, and bringing it back up, slowly.

Okay, I'll bite. Where do you go surfing in Central Florida?

It wouldn’t be the first time they built a mathematical and physical model of the Isar River in Munich’s inner city, of which the Eisbach is a part.

https://iprpraha.cz/uploads/assets/dokumenty/sharing_experie...

Sure they could... the problem is just that apparently no structural changes were made during the cleanup, but the wave was there before they turned the water off and gone after they turned it back on. And they don't have to wait for a year, they can adjust the flow - the wave is situated in a "brook" very near the point where it exits a tunnel through which it flows under much of the city, so it's heavily regulated (see this map for all Munich "brooks" on the West side of the Isar: https://upload.wikimedia.org/wikipedia/commons/f/f3/Karte_M%... - blue are the current ones, dark blue is in tunnel, the purple ones are historical, the Eisbach is #55 in the top right corner).

I’m sure they will repair it in no time. It’s too much of a tourist attraction to just let it be.

Just adding that when I rode it, they had slabs of wood under the bridge to manipulate it. Sounds like they may not do that anymore