Why Anti-Corrosion 3-in-1 Radar Flow Meters Are Becoming Critical for Wastewater, Stormwater and River Monitoring

 Product concept: upgraded anti-corrosion housing for harsh water-monitoring environments.

The water-monitoring challenge is moving beyond simple flow measurement

Water utilities and infrastructure operators are under growing pressure to understand what is happening inside rivers, drainage channels, wastewater systems and stormwater networks in real time. In these environments, the measuring point may be exposed to sewage, sediment, salt spray, humidity, debris and rapid changes in water level.

For many installations, the challenge is therefore not only accuracy. The instrument also has to survive the environment, remain accessible to remote operators and deliver data that can be used for alarms, pumping decisions, maintenance and long-term analysis.

This is creating a practical role for non-contact radar measurement. A radar system mounted above the water can measure surface velocity and water level without putting a sensing probe directly into the wastewater stream. When velocity and level are combined with channel geometry and a hydraulic model, the system can calculate flow rate without changing the hydraulic boundary conditions of the channel.

Why anti-corrosion protection matters

Corrosive conditions are common around sewage systems, industrial drainage, coastal infrastructure and wastewater discharge points. A sensor may be exposed to moisture and aggressive atmospheres even when it is not submerged. The upgraded housing shown in this product configuration adds an anti-corrosion coating to the enclosure and combines it with IP68 protection.

Non-contact measurement reduces direct exposure of the measurement element to wastewater and suspended solids.

Anti-corrosion coating is intended for harsh, humid and corrosive field environments.

IP68 protection supports outdoor, wet and flood-prone installations.

6 kV lightning protection adds an additional layer of protection for exposed monitoring points.

A wide operating range of -30°C to +80°C supports deployment across different climates.

Product measurement and communication specifications

A 3-in-1 measurement architecture

The system is designed around three related hydraulic values: water velocity, water level and calculated flow rate. The radar velocity measurement is combined with the measured water level and channel cross-section information. The resulting flow calculation can support monitoring of open channels, rivers, drainage routes and wastewater systems.

This architecture is particularly useful when operators need more than a single level value. A rising water level can indicate a blockage or flood risk, while velocity and calculated flow provide additional context about how quickly water is moving through the system.

Current market signal: England's storm-overflow network

England provides a clear example of how water monitoring is becoming more data-driven. The Environment Agency reported that every storm overflow in England now has an event-duration monitor. In 2025, England recorded 291,492 monitored storm-overflow spill events, down 35% from 2024, while total monitored spill duration fell 48%. Average spills per overflow fell from 31.8 in 2024 to 20.5 in 2025. The Environment Agency also notes that unusually dry conditions in 2025 influenced the year-on-year improvement, so the figures should not be interpreted as a technology-only effect.

Figure 1. England monitored storm-overflow spill events, 2024 vs. 2025. Source: Environment Agency, published March 26, 2026.

Since January 1, 2025, water and sewerage companies in England have also been required to publish storm-overflow discharge information in near real time, including the start and end of discharge events. [2] This regulatory direction increases the value of reliable field measurement, communications and data platforms.

United States: smart sewer programs show the value of real-time data

The U.S. Environmental Protection Agency documents several smart-sewer programs where real-time sensors, controls and data systems are used to reduce overflows and improve wastewater-system decisions. South Bend, Indiana, installed 120 smart sensors and actuators; EPA reports that the program reduced combined sewer overflow volume by more than 70%, roughly 1 billion gallons per year, while saving about $1.5 million annually in operating and maintenance costs and $500 million in avoided capital improvements.

EPA also reports a Louisville and Jefferson County Metropolitan Sewer District program that reduced combined sewer overflows by 1 billion gallons annually and estimated about $117 million in savings compared with the original long-term control plan. Cincinnati and Evansville are additional examples of utilities using real-time monitoring and control to reduce overflow volumes.

Figure 2. Selected reported annual CSO volume reductions in U.S. EPA smart-sewer case studies. Values are reported outcomes, not estimates for this product.

 Australia: non-contact radar for rapidly changing wastewater levels

A published Australian wastewater application from KROHNE describes a sewage pumping station where a hydrostatic probe was prone to clogging and did not provide the desired response to rapid level changes. A non-contact 80 GHz radar was trialled for continuous wastewater level measurement. KROHNE reports that the radar was not affected by sludge build-up, offered IP68 protection and helped operators monitor rising levels and take action to control the sewer and activate a secondary pump during high-flow and high-level weather events. [4]

The case is relevant to the broader market because it demonstrates why non-contact measurement can be attractive in wastewater environments: avoiding direct contact with sludge and reducing wear can simplify long-term operation. The Honde 3-in-1 radar architecture extends this concept by combining level and velocity measurement with calculated flow rate.

Recommended solution architecture for a remote monitoring site

 Three practical deployment scenarios

1. Underground drainage and sewer channels

A radar unit can be installed above the flow in a drainage or sewer channel, keeping the measurement principle non-contact. The combination of water level, velocity and calculated flow can help operators identify abnormal changes, monitor capacity and support maintenance planning. For sites with difficult access, 4G, LoRa or LoRaWAN can reduce the need for frequent manual data collection.

2. Coastal and salt-exposed infrastructure

Coastal drainage outlets and wastewater discharge points can combine high humidity, salt spray and wind-driven water. Anti-corrosion housing and IP68 protection are therefore useful design features. Remote communication can allow operators to inspect trends without visiting the site after every weather event.

3. Stormwater and flood-prone channels

During heavy rainfall, water level can rise quickly while velocity changes at the same time. A 3-in-1 radar system can provide a broader hydraulic picture than a level-only sensor. Thresholds can be configured so that an abnormal rise in level or flow generates an alarm through the cloud platform and relay system.

Where the product fits best

 Core advantages for system integrators and utilities

Non-contact measurement: no submerged velocity probe is required for the radar measurement principle.

3-in-1 monitoring: velocity, water level and calculated flow rate can be managed from one monitoring point.

Harsh-environment protection: anti-corrosion coating, IP68 housing and 6 kV lightning protection.

Wide measurement capability: 0.03–20 m/s velocity and 0.2–7.0 m water-level ranges.

Multiple interfaces: RS485, RS232 and 4–20 mA for connection with PLC, SCADA and existing instrumentation.

Flexible IoT deployment: optional GPRS/4G/Wi-Fi/LoRa/LoRaWAN communication with MQTT/JSON support.

Cloud-ready operation: real-time values, historical records and alarm/relay functions can be integrated into a remote monitoring system.

Field-service friendly: handheld meter and data logger options support commissioning and maintenance.

Conclusion: from a flow meter to a connected water-monitoring node

The direction of modern water infrastructure is clear: operators need more continuous data, better visibility of remote assets and faster response to abnormal hydraulic conditions. Regulatory monitoring in England and smart-sewer programs in the United States show how field sensors are becoming part of wider data and control systems rather than isolated instruments. [1][2][3]

For wastewater, stormwater, river and coastal applications, an anti-corrosion, IP68, non-contact 3-in-1 radar system provides a practical combination of hydraulic measurement and remote connectivity. When paired with a handmeter or data logger, wireless communication, MQTT/JSON and a cloud platform with alarms, the radar becomes more than a flow meter: it becomes a field data node for modern water infrastructure.

For project engineers and system integrators, the key selection criteria are therefore not only flow accuracy. Environmental protection, measurement range, communication options, integration capability and long-term maintenance requirements should be evaluated together.

Frequently asked questions

Can the radar measure wastewater without contacting the water?

Yes. The radar measurement principle is non-contact, which is useful for sewage, drainage and open-channel environments where submerged probes may be exposed to sludge or debris.

What does 3-in-1 mean?

The configuration combines water velocity measurement, water-level measurement and flow-rate calculation in one monitoring solution.

Can it connect to SCADA or PLC systems?

Yes. RS485, RS232 and 4–20 mA interfaces are available. The wireless solution can also support MQTT/JSON for IoT integration.

Can the system be used for remote sites?

Yes. Optional GPRS/4G/Wi-Fi/LoRa/LoRaWAN communication can transmit data to a remote platform, subject to site network availability.

Is it suitable for corrosive environments?

The upgraded configuration uses an anti-corrosion coating and IP68 protection. Site-specific chemical exposure and installation conditions should still be checked before deployment.

Is this an actual Honde customer case?

The U.S., UK and Australia examples in this article are publicly documented industry cases used to explain market demand and application requirements. They are not presented as Honde customer installations.

For more sensor information and customized IoT solutions, please contact Honde Technology Co., LTD.

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