Success Story
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Real-time water level monitoring
Real-time water level monitoring is first and foremost about protecting people and property from flood risk. With reliable data available at all times, local authorities can issue earlier warnings, deploy resources precisely, and reduce the exposure of residential areas to flooding and storm surges.
Born from the CELTIC project, the ALT’O is WATTECO’s LoRaWAN® sensor dedicated to water level measurement. Lorient Agglomération deployed it across its water management sites to monitor water levels continuously and alert field teams whenever a threshold is exceeded.
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Technology
FMCW radar 61 GHz
No contact with water |
Range / Accuracy
30 cm to 8 m
±10 mm · 1 mm resolution |
Protocol
LoRaWAN® Class A
Public or private network |
Battery life
2 to 5 years on battery
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Summary
| The challenge | The ALT’O solution | The benefits |
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No continuous water level measurement
Costly on-call rotations for field teams
Unable to model flood risk
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FMCW 61 GHz radar sensor, no contact
Adjustable measurement frequency based on detected water level
Immediate alert if threshold exceeded (high or low)
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24/7 monitoring without field visits
Fewer unnecessary on-call callouts
Targeted, documented on-site intervention
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The challenge
Reactive management where anticipation is needed
- —Lorient Agglomération manages several hydraulic risk sites under its water management responsibilities. On these sites, a water level rise that goes undetected in time can expose residential areas to flood risk, making continuous monitoring essential.
- —No continuous water level data: decisions made blind
- —Systematic on-call rotations, costly in human resources
- —Sluice gates operable on-site only, lengthening response times
- —Unable to model hydraulic behaviour under climate forcing
The solution
A three-layer system, from measurement to action
The CELTIC project led to the development and deployment of the ALT’O, a LoRaWAN sensor specifically designed to measure water levels in natural environments, resistant to spray, battery-powered for years, transmitting over several kilometres with no wired infrastructure.
| SENSORS | Adaptive measurement frequency based on detected water level (to optimise battery life). Threshold crossings (high or low) trigger an immediate alert. Transmission over the territory’s private LoRaWAN network. |
| PLATFORM | Data cross-referenced with weather, tidal coefficients and historical records. Machine learning model to anticipate threshold breaches. |
| SERVICES | Alert triggered by the ALT’O when a threshold is exceeded. Field teams intervene manually on site. |
« The goal is to favour prediction over repair »
Water Management Department — Lorient Agglomération
The sensor
ALT’O, a sensor born from the CELTIC project
The ALT’O is based on FMCW radar technology at 61 GHz, which sends a radio wave toward the water surface and calculates the level from the reflected signal, with no contact with the medium whatsoever, compatible with fresh, brackish, saline or polluted water.
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Technology
FMCW radar 61 GHz
No contact with water |
Range / Accuracy
30 cm to 8 m
±10 mm · 1 mm resolution |
Protocol
LoRaWAN® Class A
Public or private network |
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Environments
Fresh, brackish,
saline, polluted water |
Battery life
2 to 5 years on battery
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Alerts
Min/max threshold
Sensor displacement |
Differential data compression: The ALT’O uses differential data compression, only variations from the previous measurement are transmitted, reducing the volume of data sent over the LoRaWAN® network and minimising the digital footprint of the deployment.
Companion sensor
The ALT’O can be paired with the CLOS’O, WATTECO’s LoRaWAN® magnetic contact sensor for open/close detection, to cross-reference water level data with the status of hydraulic regulation equipment on site.
Deployment sites
4 ALT’O sensors across 2 pilot municipalities
| Municipality / Site | Deployed sensors |
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Hennebont
Pont Jehanne-La-Flamme, quai du Pont-Neuf
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2 ALT’O sensors
Monitoring the water level of the Blavet river
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Riantec
Le Riant
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2 ALT’O sensors
Monitoring water levels on both sides of the sluice gates
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ALT’O sensors at Riantec — Water level monitoring on the Riant pond
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ALT’O sensor on the Jehanne-La-Flamme bridge in Hennebont — monitoring the Blavet river water level
Operational benefits
- —Continuous 24/7 water level monitoring via the ALT’O
- —Immediate alert as soon as a critical threshold is crossed
- —Fewer unnecessary on-call rotations and field visits
- —Targeted, documented manual intervention on site
- —Open data available via the “Lorient Mon Agglo” platform





