River waves · building, running, surfing

Wave types and technology: how river waves are built and who builds them

Every standing wave forms in the same way: fast water meets slower water, and the hydraulic jump throws up the surface. How you get the water to do that is a question of construction – and that ranges from two wooden boards to a hydraulically controlled steel installation. This article sorts the systems, names examples and costs where they are documented, and introduces the suppliers that plan and build river waves. It is an overview, not a recommendation: which construction suits the Rems will be decided by the feasibility study. → Feasibility study

The construction types at a glance

For clarity: wave installations such as Citywave (Osnabrück, Berlin, Munich) or the Unit Surf Pool in Langenfeld generate the wave with pumps in a basin. They do not need a river, but they do need electricity in the order of several hundred kilowatts and cost accordingly to run. River waves run on the power of the water; if they need electricity at all, it is only for the controls.

Fixed ramp and bed sill

The simplest system: a fixed ramp or sill with a suitable geometry backs up the water, accelerates it and lets it hit the tailwater at the bottom. The Almkanal wave in Salzburg is the textbook example: a timber ramp in a regulated channel with a constant discharge of around 5 m³/s, optimised using a flow model, €90,000 in construction costs, two movable boards for fine adjustment. Augsburg developed the idea further: precast elements of recycled concrete with carbon reinforcement, inserted into an existing bed sill, a spoiler on the bed adjustable by hand crank. The Munich Floßlände was restored in 2014 with built-in slats.

Advantages: cheap, robust, no hydraulics, hardly any maintenance. Disadvantages: a fixed geometry only works well within a narrow discharge range. If the water level changes, the wave changes – or disappears. With a fixed ramp, readjusting usually means: drain and rebuild. That is why this type is suited above all to regulated channels with an even discharge, less so to natural rivers with large fluctuations. → Case study Almkanal wave · → Case study Augsburg

Hydraulically adjustable ramps and wave bodies

The newer German river waves work with steel modules whose angle can be adjusted steplessly via hydraulic cylinders – during operation, by tablet or app. If the water level rises, the ramp is set flatter or lowered completely; during a flood it lies on the bed and frees the discharge cross-section. The University of Innsbruck researched the principle in its hydraulic engineering laboratory and in doing so also showed how sensitive it is: small changes to the geometry can produce a dangerous roller with recirculation instead of a wave. From this, Dreamwave GmbH developed a patented system that stands in Nuremberg (three modules, 8 metres) and Hanover (three wave bodies, up to 8.6 metres); in Hanover the wave bodies cost around €1.4 million. Pforzheim shows the self-built variant: a steel frame with timber planking, ten hydraulic cylinders, app control, around €80,000 in materials and more than a thousand hours of voluntary work.

Advantages: the wave can be adapted to any water level, which extends the season and eases permitting, because the flood safety proof can be provided via the lowering. Disadvantages: high investment, technology in the water (hydraulics, seals, controls), maintenance and sediment – Hanover stood idle for three months after the 2023/24 flood because of sand ingress. → Case study Nuremberg · → Case study Hanover · → Case study Pforzheim

Flap weir in a diversion channel

The.Riverwave in Ebensee on the Traun is the largest artificial river wave in Europe: a 120 to 140 metre long concrete channel diverts water from the Traun, two coupled steel flaps with hydraulic cylinders shape a 10 metre wide wave whose height can be regulated between 0.5 and 1.5 metres. The installation runs on around 250 days a year, cost around €2 million net and was opened in May 2020 after four years and nine months of planning and construction. The client and operator is a private company; the wave design comes from the McLaughlin Whitewater Design Group from the USA, which also developed the "WaveShaper" in the river park in Boise (Idaho). Pneumatic or hydraulic flaps have been common in whitewater construction for years; suppliers such as Obermeyer Hydro advertise that a wave can be reconfigured in minutes without anyone having to get into the water.

Advantages: large control range, real wave height, operation almost all year round. Disadvantages: a dedicated diversion channel is the most expensive item of all; the system pays off where space and water volume are available and an operator is counting on admission fees.

Conversion of an existing weir

Augsburg showed at an existing bed sill what a conversion can do: the water already fell over a step there, "all" that was missing was the shape. Winterbach is different. The outlet structure of the flood retention basin (locally the "Remswehr") narrows the river and can impound it with its gates; at normal water levels, however, the Rems flows straight through, there is no step. The head for a wave has to be created first – by an installation such as a ramp, a sill or an adjustable board, by a constriction, or a combination. The feasibility assessment must clarify whether and how this can be achieved. The advantage remains: no channel has to be dug, structure, banks and access are there, and the costs are concentrated on the wave itself. The limits are set by the river: a natural discharge fluctuates, and a weir conversion is a watercourse modification with all the requirements for flood protection and fish passage. → Winterbach site · → Ecology and permits

Who plans and builds river waves

The market is small and international. The following overview names companies and institutes that have demonstrably planned or built river waves, without rating and without claiming to be complete; suppliers' own claims are marked as such.

Anyone comparing suppliers should look at three things. First, references in comparable watercourses – a wave in a regulated channel says little about a natural river. Second, the question of who does the permit planning: the suppliers deliver the component, the water-law proof is usually provided by a local hydraulic engineering firm. Third, operation: adjustable systems need someone to operate them, maintain them and lower them in the event of a flood.

What this means for the Rems

Winterbach does not start from zero. The structure is there, banks and access are in place. The question for the feasibility assessment is therefore not "which system do we buy" but "which installation creates the necessary head and a surfable wave at the discharges the Rems carries on most days – and how does it remain harmless during a flood". The answer may be a fixed geometry, an adjustable element or both. The examples show the range: from a few tens of thousands of euros for a fixed ramp in a channel to millions for channel and hydraulics. Which order of magnitude applies to the Rems will be told by the discharge figures and the model calculation – not the catalogue. → Costs and funding

Frequently asked questions

Which construction type is the cheapest?

A fixed ramp in an existing channel with an even discharge – Salzburg cost €90,000, Pforzheim around €80,000 plus own labour. As soon as a channel has to be dug or hydraulics installed, the costs rise to hundreds of thousands or millions of euros.

Does a river wave need electricity?

Not for the wave itself – it runs on the power of the river. Only the controls and hydraulics of adjustable installations need electricity. Wave installations with pumps (Citywave, Surf Pool), by contrast, need several hundred kilowatts.

Why are almost all new waves adjustable?

Because the discharge of a river fluctuates. An adjustable ramp adapts the wave to the water level, extends the season and can be lowered during a flood – which eases the flood safety proof in the permitting procedure.

Who builds river waves in Germany?

The two large installations in Nuremberg and Hanover come from Dreamwave GmbH in Cologne; Pforzheim built its installation itself with engineering partners, Augsburg with the Augsburg Technical University of Applied Sciences. International suppliers come mainly from North America.

Sources: University of Innsbruck, „Die perfekte Welle“ (The perfect wave, 20.08.2015) and newsroom 01.04.2022 · Dreamwave GmbH, dreamwave-international.com · Surfers Mag, 25.08.2022 (Hanover) · blackforestwave e.V., „Welle“ · riverbreak.com, interview blackforestwave · DonauConsult, reference Almkanal · almkanal.at, „Projekt Surfwelle“ · Augsburg Technical University of Applied Sciences, project page Surfwelle · IGSM, „Floßlände“ · The.Riverwave, „Team“ and „FAQ“; FM4, 14.05.2020; Allplan blog, 19.01.2022; Bayerische Ingenieurekammer-Bau, 23.03.2021 · Boise Whitewater Park, project information · riverbreak.com, „Case: River wave adjustability“ (08.11.2015) · Surf Anywhere, „Types of adjustable river waves“ (19.07.2022) · Obermeyer Hydro, „Whitewater“ · S2O Design · Hydrostadium · Merrick Whitewater / riversurfparks.com · echo24.de, 2024 (Heilbronn) · landratten.org, Unit Surf Pool Langenfeld · wavepoolmag.com, 17.02.2021 (Citywave)

Last updated: 15 October 2026 · Initiative Remswelle