The questions that come
before the decision.

Technical product questions are covered on the product pages; questions about the measures catalogue in the consulting section.

What is WAMO?

WAMO is an automated measurement station for the continuous monitoring of lakes, rivers and other surface waters. The station records water parameters every 1 to 15 minutes and transmits them via the mobile network to SWIM. This reveals changes that go undetected between two rounds of sampling.

What is SWIM?

SWIM is the satellite-supported complement. We analyse Sentinel-2 and Landsat data and derive layers for Secchi depth, algal concentration, turbidity and chlorophyll – across entire catchments, at 10 to 30 m per pixel and with an update every 3 to 10 days. Suitable for standing and slow-flowing waters from around 5 ha.

What is meant by the e.Ray network?

WAMO measures at a single point, SWIM measures across the whole area, and the base station maintains the connection even where there is no mobile coverage. Only the combination produces a continuous situational picture: the satellite analysis shows where conditions are becoming critical, the sensor station shows exactly what is happening there. The building blocks can also be used individually.

Does WAMO replace conventional sampling and laboratory analysis?

No. WAMO adds continuous data to sampling, laboratory analysis and biological surveys. This makes it possible to identify critical moments, short-term peaks in pollution load and spatial differences in a more targeted way. Laboratory investigations can then be planned and interpreted more effectively.

What does e.Ray mean by water intelligence?

Water intelligence means linking measurement data, historical data, weather information, remote sensing and models in such a way that concrete decisions can be derived from them. The goal is not more data, but a better answer to the question: what is happening in the water body, why is it happening and where should action be taken?

Can existing measurement points and data sources be integrated?

Yes. Existing measurement stations, laboratory values, water-level data, weather data and GIS information can be connected; we merge those sources with WAMO and SWIM data into a shared situational picture. Before a project starts, we review data formats, interfaces and the quality of the existing data.

Which water bodies is the system suitable for?

For lakes, rivers, canals, retention basins, dams, bathing waters and drinking-water reservoirs. Measurement points and sensors are not selected generically, but according to the structure of the water body and the question to be answered.

How is the quality of the measurement data ensured?

The sensors come from established professional manufacturers (Endress+Hauser, S-CAN/Badger Meter, bbe Moldaenke), not from in-house builds. In addition, there are plausibility checks, maintenance and calibration. Every reading carries a quality flag: unusual values are marked and assessed in the context of the measurement and of the water body, rather than being presented as a confirmed finding.

Who owns the data collected?

You do. e.Ray operates the measurement technology and the platform; the data from your water body remains yours. Hosting is in the EU, GDPR-compliant and without transfers to third countries. Access, usage rights, retention periods and disclosure are agreed in writing before the project starts – including the question of what stays internal, what is shared between the parties involved and what is presented publicly.

What does monitoring cost?

That depends on the size of the water body, the parameters, the number of measurement points and the contract term; we therefore quote prices per project on request. You can start free of charge with the SWIM trial analysis: a sample map and a report covering the last 12 months of your water body, as a basis for deciding on continuous operation.

How quickly is a station ready for operation?

The standard delivery time is 6 to 10 weeks. On-site setup is completed in a single day: anchoring, floating the station into position, cloud connection and sensor calibration.

Does e.Ray also carry out water-body restoration, or only monitoring?

Both, in that order. Measurement comes first; from it follow the analysis of the water body, the selection and planning of measures, aeration close to the bed as a technical building block in its own right, and impact monitoring during operation. Structural interventions such as de-sludging or reshaping the shore are carried out by specialist firms on site; we coordinate them and verify what they achieve in the water body.

What are nanobubbles and what can they achieve?

Nanobubbles are very small gas bubbles. They behave differently from coarse air bubbles and remain in the water longer instead of rising quickly. This allows oxygen to be introduced where it matters most in biological and chemical terms: close to the bed, at the sediment-water interface. Such an oxygen supply can shrink low-oxygen zones and support the aerobic breakdown of organic matter. How pronounced the effect is depends on the water body and only becomes apparent in the readings.

How do I become an e.Ray partner?

Write to us and tell us what you have in mind. We work with local initiatives and associations, with service and sales partners in the regions, with companies on water and climate projects, and with research, limnology and sensor technology. In a first conversation we clarify what form of cooperation makes sense and what each side brings to it. The partners page shows who we have worked with so far.

We are an association and would like to look after our water body. Is that possible?

Yes. We support initiatives, associations and individual volunteers who look after their lake, pond or stream. Tell us which water body is involved and what you are observing there. We then work out together what can usefully be measured, what data is already available and how that commitment turns into a result that can also be defended to the municipality and the public authority.

What concrete benefit does continuous water monitoring bring a municipality?

You receive early indications of blue-green algae risks, oxygen deficits, unusual turbidity or changes in water level. Measures can therefore be targeted more precisely, unnecessary inspection trips are no longer required, and every decision can be substantiated afterwards.

How does monitoring help with blue-green algae and bathing water problems?

WAMO detects rising phycocyanin and chlorophyll readings and compares them against stored thresholds and trend models – typically 24 to 72 hours before the algal bloom becomes visible. This does not replace a definitive cyanotoxin analysis, but it does allow an earlier risk assessment and more targeted sampling. That helps avoid both premature closures and delayed responses.

Can the number of closure days at bathing lakes be reduced?

Continuous data provide a better basis for decisions that are differentiated in time and space. Public health authorities and operators can investigate critical developments earlier and support all-clear notices more reliably. The formal decision on a closure remains with the responsible authority.

Is the solution suitable for public procurement?

We supply the documentation normally required in tender procedures and provide references from comparable clients. We agree the specification of services and the lot structure with you before the tender goes out.

How does monitoring help with water-body maintenance?

Measurement data show which stretches of water are under particular strain and which problems recur. Maintenance work can therefore be prioritised according to actual need. In the long run it also becomes verifiable whether a measure has achieved the intended effect.

Can WAMO be used for heavy-rainfall and flood preparedness?

Yes. Water level, precipitation and discharge information can be combined with existing measuring points and local risk maps; this yields site-specific warning thresholds and information chains. The base station operates independently of grid power and keeps the connection up even when local networks fail. A robust warning system always has to take the catchment area, response times and local hazard points into account.

Can citizens access selected data?

Yes. Selected data can be made available through a public dashboard or the municipal website, while internal measurement, alert and technical data remain separate from it. This creates transparency without prematurely publishing unverified individual readings.

How much staff effort is involved?

Little. The stations run on solar power without a grid connection, and maintenance intervals are 3 to 6 months depending on the water body. Instead of continuous manual observation, alerts reach the people responsible.

How quickly can a pilot project be implemented?

A pilot starts with the choice of water body, the question to be answered and the measuring points; sensors, data transmission, responsibilities and maintenance are then agreed. With a standard delivery time of 6 to 10 weeks, a pilot is therefore operational within one season – and serves as the basis for later expansion into a municipal measurement network.

Is there support with funded projects?

Yes. We support municipalities and districts with technical monitoring and evaluation concepts, for example in the areas of natural climate protection, water-body development, heavy-rainfall preparedness and digital public services. Which funding line applies depends on the individual programme; we advise on the right choice.

Does aeration replace tackling the causes?

No. Aeration is a supporting measure, not a substitute for working on the causes. As long as nutrients keep arriving from the catchment area, the pressure on the water body remains. A targeted oxygen supply can ease phases of stress and buy time, while inflow management, buffer strips or sediment treatment address the cause. The right combination follows from the analysis of the water body.

Roughly what does aerating a water body cost?

That can only be quantified reliably once the water body has been analysed. Dimensioning depends on depth, area, stratification and power supply – a near-bed Nano-Bubble line is costed differently from a single aerator lance. We state the range in the quotation as soon as the requirement is clear, separating capital outlay from ongoing operation.

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How can an entire catchment area be monitored?

Monitoring points are positioned along the relevant tributaries, water-body sections and pollution hotspots, and combined with area-wide satellite analysis. This creates a spatial picture of how the waters are developing: you see where pressures arise and at which locations measures are likely to have the greatest effect. Area monitoring is built precisely for this kind of scaling across many water bodies.

Which operators use WAMO?

Operators of dams, drinking-water reservoirs, bathing waters, wastewater treatment plants, retention basins, water-management facilities and industrially used water bodies.

Which operational risks are detected earlier?

Oxygen deficits, pronounced changes in temperature or turbidity, elevated algal activity, unusual conductivity readings, altered water levels and abnormal patterns following rainfall events.

Can short-term inputs after heavy rainfall be detected?

Yes. Continuous measurement reveals changes caused by surface runoff, combined sewer overflows and other event-related inputs that individual grab samples easily miss. The readings provide initial indications; identifying the substances precisely can require additional sampling or laboratory analysis.

Can individual alert thresholds be set up?

Yes. Thresholds and escalation paths are adapted together with you to the site, its use and your operational response options. What matters is combining rigid limit values with trends over time and multiple parameters in order to reduce false alarms.

Are alerts and acknowledgements documented?

Yes. Every notification and every acknowledgement is logged in a traceable way – robust enough for audits and committee scrutiny.

Can WAMO be used for drinking-water reservoirs?

Yes. Continuous measurement gives early indication of changes in raw-water quality and of risks such as stratification, oxygen deficits or elevated algal activity. The analytical detection of cyanotoxins or other pollutants remains a task for suitable laboratory methods.

Are measurements at different water depths possible?

Yes. For stratified lakes and reservoirs, profiling or depth-resolved measurement concepts are appropriate. This makes it possible to examine temperature and oxygen stratification as well as critical developments in deeper water layers.

Can discharges or the effects of facilities be monitored?

Monitoring points upstream and downstream of a discharge reveal changes over time. A robust assessment has to take flow, weather, background pollution and further inputs into account. We therefore develop the measurement concept together with you and, where appropriate, with the competent authority.

Can renaturation or nutrient-reduction measures be monitored?

Yes. To do so, the baseline condition, target values and suitable reference areas are defined; changes are then tracked before, during and after the measure. This produces more robust evidence of impact than individual snapshots can provide.

How much maintenance is required?

Maintenance intervals are 3 to 6 months depending on the water body; specifically, they depend on the sensors, biofouling, sediment load and measurement interval. Each monitoring network receives its own maintenance and quality-assurance concept, and status messages from the stations help to schedule visits where they are needed rather than on a fixed calendar.

Can WAMO data be integrated into existing operational control systems?

Yes. The data is available via API, as WMS/WMTS layers for GIS systems and as an export, and it can be passed to specialist applications, data platforms or control systems. Access rights and security requirements are agreed in advance.

Can data be shared between several municipalities or association members?

Yes. Role and permission concepts allow different levels of access for the association, municipalities, consultancies and public authorities. This creates shared data holdings without every party automatically having access to all internal information.

For which water bodies is near-bed aeration an option?

Above all for standing and slow-flowing waters with little water movement: ponds, lakes, reservoirs, retention basins and other retention areas. Critical cases are stratified waters in which the deep layer is cut off from the surface for weeks and the oxygen there is depleted. Whether aeration makes sense, and where it should be applied, is clarified by depth profiles of oxygen and temperature before planning begins.

How can it be verified that aeration actually works?

Through measurements before, during and after operation. It makes sense to record a baseline over at least one season, then to observe oxygen, temperature and stratification at several depths, together with a reference area in the same or a comparable water body. Weather, inflows and use have to be part of the assessment; otherwise every change is prematurely attributed to the system. The same readings can then be used to fine-tune how the system is operated.

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How does continuous monitoring help with implementing the Water Framework Directive?

It supplements official monitoring programmes with measurement data at high temporal resolution, making pressure events, seasonal developments and long-term change visible. Monitoring networks can therefore be planned more precisely, hypotheses about causes can be tested, and measures can be evaluated more robustly.

What exactly does the WFD require?

The Water Framework Directive requires good ecological and chemical status, or good ecological potential, and works with six-year river basin management plans and programmes of measures. The German Surface Waters Ordinance (Oberflächengewässerverordnung) requires monitoring sites, parameters and frequencies to be selected so that a sufficiently reliable and accurate assessment is possible.

Is WAMO a WFD assessment method in its own right?

No. Formal status assessment is based on the legally defined biological, hydromorphological, chemical and physico-chemical quality elements. WAMO supplies supplementary data for interpretation, operational monitoring, monitoring network planning and impact assessment. The technical and legal classification remains the task of the competent authorities.

Which information gap does continuous monitoring close?

Assessments and river basin management plans look at multi-year periods. Yet many relevant processes in a water body – oxygen deficits, algal growth, pressures after heavy rainfall – develop within a few hours or days. Continuous measurements bridge the two time scales and create a data basis for day-to-day water-body management.

How can operational monitoring be supported?

For water bodies that are unlikely to meet their objectives, additional measurement data helps to capture the extent and dynamics of the pressures more precisely. We align measurement parameters, locations and temporal resolution with the specific pressure hypothesis – in keeping with the pressure-related selection of sensitive quality elements provided for in the Surface Waters Ordinance.

Can monitoring networks be prioritised at state level?

Yes. Water bodies can be grouped into priority classes on the basis of status data, pressures, use, catchment area, need for measures and existing monitoring density. This makes it possible to identify the locations where additional continuous measurements deliver the greatest gain in knowledge.

How does the platform support impact verification for WFD measures?

Measures, target values, monitoring sites and time periods are represented together. This allows changes to be examined before and after a measure and compared with suitable reference areas. The result is a traceable basis for prioritisation, evaluation and reporting.

Can existing state data and specialist systems be integrated?

Yes. The platform is designed as a shared access layer for different water data: measurement data, reports, GIS layers, water body information and the status of measures can be brought together and made accessible through a map view. Which systems are connected directly depends on interfaces and data rights.

How are uncertainties and data gaps presented?

Readings always appear together with quality status, availability, temporal resolution and, where relevant, uncertainties. The aim is not apparent completeness but a transparent account of what can reliably be derived from the data – and where additional investigations are required.

Are comparisons across states or authorities possible?

Yes. Shared data models, standardised metadata and comparable evaluations allow water bodies to be viewed across organisational boundaries. Differing measurement methods, water body types and assessment bases are indicated transparently.

What new requirements on substances are public authorities facing?

With the EU Water Package (Directive (EU) 2026/805, adopted in April 2026), the EU is tightening the requirements for pollutants in surface water and groundwater: additional PFAS, pesticides and pharmaceuticals, plus microplastics and indicators of antimicrobial resistance on the watch lists. Member States must transpose this into national law by the end of 2027. WAMO does not measure these substances with sensors. The platform brings laboratory, monitoring and context data together so that evidence from different sources can be assessed in one place. (As of August 2026)

Why is current measurement and reporting practice often not sufficient?

Many water bodies are subject to nutrient inputs, structural change, pollutants and climate effects at the same time. In Germany, according to the data of the third river basin management cycle, only around nine percent of surface waters achieved good or high ecological status, or good potential. Continuous data does not solve this on its own, but it does help to understand pressures and measures far more precisely.

Does the platform replace our existing specialist system?

No. Specialist systems, monitoring network databases and GIS remain the system of record for their respective data. Our data platform sits above them as a connecting layer and brings together what is currently held in separate systems. It does not write back into your specialist systems and does not take over official record-keeping. The benefit lies in the shared view of the water bodies, not in replacing existing software.

Which data sources can be integrated beyond your own monitoring sites?

Openly available and official data, hydrological base data such as water level, discharge and precipitation, satellite archives for area and history, information on catchment area and water body structure, water balances, and the results of biological surveys. The question at hand decides which source is worthwhile: we integrate what together produces a better answer, not everything that is technically available.

What about eDNA and metabarcoding?

This is a look ahead, not something we offer today. In future, eDNA samples and metabarcoding could provide indications of species and biodiversity that sensors and satellite data cannot capture; new imaging methods for identifying organisms would also be conceivable. As soon as such methods prove themselves in routine operation, we would add them to the data platform as an additional layer.

Sources: Directive 2000/60/EC (WFD) · Surface Waters Ordinance (OGewV), Annex 10 · Directive (EU) 2026/805 · German Environment Agency (Umweltbundesamt), WFD status assessment

In which formats do I receive the data?

Standardised, exportable formats with a record of origin (lineage), plus API access and WMS/WMTS layers for QGIS and ArcGIS. The data can therefore be used directly in expert reports and technical planning.

Are technical data sheets available?

Yes, one per product. Interface details are clarified project by project.

How far back does the satellite archive reach?

SWIM draws on historical satellite data, including periods before any sensors were deployed. This makes it possible to reconstruct a baseline for which no on-site measurements exist.

Can we bring e.Ray into projects as a partner?

We would be glad to. We regularly work as a technical partner in consortia and specialist planning projects, taking on the measurement concept, operation and impact verification, while responsibility for the planning remains with you.

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