Rems and Winterbach · River, water, nature and history

Water quality of the Rems: what we know and what we must measure

Anyone who falls on a river wave goes under and swallows water. That is why water quality is not a side issue for a surf wave but the first question: it is what the Neckarwelle in Stuttgart failed on in 2019. This article brings together what is publicly known about the Rems, what that means for Winterbach and what the proof that a permit demands has to look like. It also says what we do not know. → Questions and objections

Two different questions

"Is the river clean?" means two things that need not have anything to do with each other. River ecology asks whether fish, small animals and plants have a good habitat; it is assessed under the EU Water Framework Directive, and for it the structure of the watercourse, passability and nutrients are decisive. Hygiene asks whether a person can fall ill when going under; it is measured in germs, above all Escherichia coli and intestinal enterococci, the key values of the EU Bathing Water Directive. A river can be ecologically moderate and hygienically harmless – or the other way round. For a surf wave, the second question counts; the first belongs in the permitting procedure. → Ecology and permits

The status under the Water Framework Directive

The Rems is a first-order watercourse; the responsible authority is the Stuttgart Regional Council (Regierungspräsidium). For management planning it is divided into two water bodies: "Rems up to and including the Walkersbach" upstream and "Rems below the Walkersbach" – which includes the stretch through Schorndorf, Winterbach and Remshalden. The Regional Council's accompanying documentation for the management period 2022 to 2027 rates this water body as follows: the ecological status is "unsatisfactory", the chemical status "not good". That sounds worse than it is for the question of the wave – and it is worth breaking the rating down.

The saprobic index, the measure of pollution by degradable organic matter and thus the classic indicator for sewage, is rated "good" in the Winterbach stretch, as is the general degradation of the small-animal fauna. What pulls the overall grade down is the fish fauna and the structure of the watercourse: passability, morphology and water balance are "not met", and the documentation names diversions for hydropower on the Rems and the Wieslauf. The chemical status is "not good" on almost every river across the state, because mercury and brominated flame retardants are measured everywhere; for the Rems, the insecticide imidacloprid and PFOS come on top. For surfing, these substances in the traces measured are not the relevant quantity – for the river as a habitat they are. The measures the Regional Council plans for the Rems aim at structure: restoration, passability, better phosphate precipitation in the treatment plants. One example lies on our doorstep: between Winterbach and Remshalden, the state restored the Rems from 2018 over 1.1 kilometres to a width of up to 100 metres, at the time the largest restoration under way in the Stuttgart administrative region.

What discharges into the river above Winterbach

Germs come from sewage treatment plants, from storm overflows of the sewer system during heavy rain and from farmland. According to the Regional Council's accompanying documentation, the treatment plants discharging into the Rems above the planned wave site include Schwäbisch Gmünd, Lorch, Urbach/Plüderhausen (the Hungerbühl joint treatment plant), Schorndorf (Weiler) and Rudersberg (via the Wieslauf). The Winterbach joint treatment plant lies downstream of the weir and plays no role for the wave site; the nearest discharge upstream is the Schorndorf-Weiler treatment plant. The Zollerwiesen plant in Schwäbisch Gmünd, at 135,000 population equivalents, is the largest in the Rems valley; a fourth treatment stage against trace substances is planned there by 2035, and in Lorch the plant is being rebuilt for 20 million euros. No treatment plant in the Rems valley is currently on the state's list of plants with trace-substance elimination. More decisive for hygiene than the fourth stage is stormwater treatment: during heavy rain, combined sewers discharge untreated into the river, and that is exactly what produced the germ peaks in the Neckar. For the Rems, the Regional Council mentions procedures still under way to identify measures at stormwater facilities – no concrete details are available.

What is measured – and what is not

For the Rems there are no publicly accessible measurement series for E. coli and enterococci. It is nowhere designated as a bathing water; in the Rems-Murr district six bathing lakes are monitored, no river. That is not a finding about water quality but about the state of the data: what nobody measures, nobody can assess. The health office of the Rems-Murr district advises against bathing in the Rems because of dangerous currents and the water quality; it considers kayaking and rowing unproblematic (as of 2024). In August 2026 the Rems-Murr district office (Landratsamt) additionally advised against bathing in the Rems and the Murr during low water – mainly to protect the river ecology, but also because low water "may be hygienically questionable for humans".

For comparison, the standards of the EU Bathing Water Directive for inland waters, in colony-forming units per 100 millilitres: intestinal enterococci at most 200 for "excellent" and 400 for "good", E. coli at most 500 and 1,000 respectively, each as the 95th percentile of a measurement series; "sufficient" is 330 and 900 respectively as the 90th percentile. At least four samples per bathing season are required, no more than one month apart. These values are the yardstick the Neckarwelle failed against, and they are the obvious standard for any surf wave.

The lesson from Stuttgart

The Neckarwelle in Untertürkheim had a feasibility study, a club and support in the district council. The State Health Office took eighteen samples from the Neckar between July and October 2018: E. coli averaged twice the bathing-water maximum and reached twenty times it in two samples; the enterococci maximum was reached almost constantly, with peaks at ten times; noroviruses were found in three of four samples examined. The peaks occurred after heavy rain, when treatment plants and storm overflow basins discharged – the Neckar is the receiving water for around 600 treatment plants, and at low water it consists of up to 37 percent treated sewage below Stuttgart's main treatment works. In March 2019 the city declared the project not permittable: the microbial load was so high that pathogens could be ingested when going under; the conditions for the water-law permit were therefore not met. The club's objection that the peaks occurred only on two to three days after rainfall and that nobody surfs on such days, and a legal opinion according to which warning signs would suffice, changed nothing. The city called the health hazard a knock-out criterion.

What the Remswelle can learn from this: first, it is the authority that measures, not the club – and it measures over a whole season, rainy days included. Second, it is not the mean that counts but the percentile: a few high peaks decide. Third, the argument "then we simply won't surf" only helps if it is part of a robust operating concept that the authority supports. And fourth, the Rems is not the Neckar: a small river with a fraction of the treatment plants in its catchment, without a large city upstream. That is a reason for confidence, but no substitute for measurements.

How other waves deal with it

No German river wave lies in a designated bathing water. The Nuremberg club writes that the Pegnitz is not a bathing water and may contain germs, bacteria, viruses and parasites, and that use is at your own risk; the city of Nuremberg collects data, according to the club the limits for E. coli and enterococci are met, and when there are signs of pollution – after heavy rain, when the sewers are overloaded – there is no surfing. In Hanover it is stated that the Leine does not meet the requirements for a bathing water and that surfing is at your own risk; the water-law permit issued by the Hanover Region stood up before the administrative court. The model is the same everywhere: measure, inform, suspend operation on polluted days. It presupposes that the standard values are met on normal days – and that is the proof Winterbach has to provide. → Operators and operation

What this means for the Remswelle

We are aware that water quality is a decisive factor – for the permit and for everyone who later stands on the wave. We will provide the necessary proof. The path is mapped out by the other waves: measurements at the wave site following the pattern of the Bathing Water Directive – E. coli and intestinal enterococci, several samples over a season, including after rain and at low water –, coordinated with the health office, plus a look at the discharges upstream, above all the storm overflows between Schorndorf-Weiler and Winterbach. What we can say today: the Rems is a small river without a large city upstream, its organic pollution at Winterbach is "good" under the Water Framework Directive, and the nearest treatment plant upstream is in Schorndorf-Weiler. What we cannot give are numbers – and we do not claim any. → Project status

Frequently asked questions

Is the Rems clean enough for surfing?

Nobody knows that in numbers today. Under the Water Framework Directive, the organic pollution of the Rems at Winterbach is "good", but there are no germ measurements, and the Rems is not a designated bathing water. We are aware that this is a decisive factor; the proof will be provided following the pattern of the Bathing Water Directive.

Why did the Neckarwelle fail on water quality?

Because in 2018 the State Health Office found E. coli in 18 samples at twice the bathing-water maximum on average and at twenty times it in peaks, plus noroviruses. In 2019 the city of Stuttgart classed the health hazard when going under as a knock-out criterion.

What does the ecological status "unsatisfactory" say about the germ load?

Nothing. The assessment under the Water Framework Directive measures habitat quality – fish, small animals, structure, nutrients –, not hygienic suitability for humans. For that, E. coli and enterococci are the standards.

Can you bathe in the Rems?

The Rems is not a designated bathing water; in the Rems-Murr district only six bathing lakes are monitored. The health office advises against bathing in the Rems because of the current and the water quality. We have not found an explicit bathing ban.

Who measures water quality for a surf wave?

In Stuttgart the State Health Office measured and the municipal health office assessed; in Nuremberg the city collects the data. For Winterbach, the health office of the Rems-Murr district is the point of contact.

Sources: Zeitungsverlag Waiblingen, "Die Rems: zum Baden nicht geeignet …" (The Rems: not suitable for bathing …), 24.08.2024 · Stuttgarter Zeitung, 21.06.2024 (bathing waters in the district) · Regierungspräsidium Stuttgart, accompanying documentation for sub-area 42 "Neckar unterhalb Fils bis oberhalb Enz", as of December 2021 · Umweltministerium Baden-Württemberg, Bewirtschaftungsplan 2021 Rhein (river basin management plan; annex with water-body tables); "Kläranlagen mit Spurenstoffelimination" (treatment plants with trace-substance elimination), as of 22.06.2026 · Stadt Schorndorf, "Gewässer, Hochwasserschutz, Starkregen" · Regierungspräsidium Stuttgart, press release "Renaturierung der Rems bei Winterbach", 08.02.2018 · Gmünder Tagespost, 26.12.2024 (Zollerwiesen treatment plant) · Tim Bückner MdL, visit to the Lorch treatment plant, 29.10.2025 · Zeitungsverlag Waiblingen, 18.04.2022 (Hungerbühl joint treatment plant) and 11.08.2026 (low-water appeal) · Landratsamt Rems-Murr-Kreis, "Niedrigwasser belastet Fließgewässer", August 2026 · Stuttgarter Zeitung, 21.06.2024 (bathing lakes in the Rems-Murr district) · Directive 2006/7/EC (Bathing Water Directive), Annexes I and IV · Stuttgarter Zeitung, "Zu viele Keime: Aus für die Neckarwelle", March 2019; "Politik fordert sauberen Neckar", 2019 · Stuttgarter Nachrichten, "Norovirus, E. coli, Salmonellen", 2019; "Die Surfer wollen zur Not klagen", 2019; "Neckar besteht aus bis zu 37 Prozent Abwasser" · Landeshauptstadt Stuttgart, statement in the participatory budget (Bürgerhaushalt), 09.04.2019 · kessel.tv, 28.03.2019 · Nürnberger Dauerwelle e.V., "FAQ" · nordbayern.de, 19.07.2024 and 24.07.2024 · Leinewelle e.V., "FAQ" · Verwaltungsgericht Hannover (Hanover Administrative Court), press release 12.01.2021

Last updated: 15 October 2026 · Initiative Remswelle