Measuring the PULS of water levels

Tracking water levels in rivers, channels, canals, and pipes is a critical issue for water authorities. VEGA has a product that can help authorities track the rise and fall of water throughout its critical infrastructure.

Rivers can suddenly overflow their banks. Drinking water can become scarce. A nature reserve may struggle with drought. In all these examples, water distribution strategies have to be rethought. This challenge is not unique to Australia, but many authorities across the globe deal with them regularly.

One such group in Belgium is the Flanders Environment Agency VMM (Vlaamse Milieumaatschappij). Although the authority can do little to change the volatility of the weather, it nevertheless plays a role in overall water policy.

The environmental agency measures and monitors water quantity and quality. It also manages water systems while levying fees on water pollution and groundwater extraction. VMM also advises on environmental permits. It is also tasked with supervising infrastructure planning and the monitoring and supply of drinking water. Regarding rivers or other flowing water, VMM relies on IoT solutions and adopts an integrated approach that limits the risk of flood damage and achieves a high ecological status.

In other words, VMM ensures that every user and consumer in the water distribution system is addressed. However, you can only monitor something that has been accurately measured.

User-friendly and low-maintenance

Radar sensors are not bothered by dirt, sunlight, fog, wind, or rain. They also do not require mechanical protection from high floodwaters. Therefore, the decision was made over 15 years ago to change the sensor type for measuring water levels. Since then, VMM has relied on radar technology from VEGA.

It first worked with the radar level sensor VEGAPULS 61 with PVDF antenna for many years, then later with VEGAPULS WL 61. During the collaboration, it appreciated the solution-oriented attitude of the Schiltach-based company.

“Whenever a problem arose, the service and additional information provided by VEGA was excellent and helpful,” said Johan Eylenbosch, a hydrographer and electrical mechanic at VMM. This was to be reconfirmed by the next project the agency undertook.

Real-time level measurements ensure safety

Due to climate change, a new challenge arose. They had to come up with a way to get a comprehensive overview of water levels at various locations at any time of day. VMM aimed to build a fine-meshed network of real-time level measuring points. Some of the critical measuring points included smaller, non-navigable watercourses.

In these smaller watercourses, information was gathered to help mitigate water shortages or predict floods. Such measured values formed the basis for taking more far-reaching decisions. These decisions included introducing local or regional water withdrawal prohibitions. VMM was mainly focused on periods of prolonged drought, which had been the day’s order in recent years.

Somewhere in the middle of nowhere

To improve water level management, VMM wanted smart IoT-level sensors to continuously measure rivers. Setting up such measuring points was only possible with considerable effort and expense until then.

“To install a river level measuring point, the sensor and adequate housing had to be set up in the middle of nowhere. The necessary cables would be laid underground. We also needed special software to configure the system. We also had to collect, amalgamate, and process the measurement data,” said Eylenbosch, citing a few of his concerns at the time.

When the new compact radar level transmitter VEGAPULS C 11 became available, many problems vanished. The instrument contains a newly developed radar microchip optimised for the requirement of water levels. Due to its high integration level, it was possible to build compact sensors.

The new VEGAPULS C 11 measures with a frequency of 80 GHz, which enables excellent signal focusing. This allows better separation of measurement signals from interference signals – measurement is thus much easier and more accurate than other measuring methods, such as ultrasonics. The small beam angle of only 8 degrees is suitable for the application.

“Some channels are very small,” said Eylenbosch. “Thanks to the narrow measuring beam, there are easier ways to install the sensor in tight spaces. For example, we can mount the sensor very close to the wall.”

The new radar sensor can be immersed in water in the event of a flood due to its encapsulated cable and protection class IP66/68,

Current measurement data around the clock

Every 15 minutes, the radar measurement is activated, and the measured value is sent to the VMM database via a remote telemetry data logger.

“This makes it possible to gain a better insight into our water supply and distribution reality and to calibrate our hydrological models,” said Eylenbosch.

Once the decision was made, VMM procured 50 compact VEGAPULS C 11 radar level sensors and installed them with microcontrollers at numerous locations in five provinces. The exact location of each one is determined via a GPS module built into the data logger.

“Most measuring points are in open watercourses and are not problematic. We could also have used ultrasonic or pressure sensors,” he said. “The radar sensors operate via Bluetooth and are easy to install. They also have a high measuring accuracy while featuring a very reasonable price. This tipped the scales in favour of radar measurement technology. The instruments are also solar-powered. That makes them even easier to operate and maintain. Their significantly lower energy consumption was helpful in many respects.”

He mentions another feature – the VEGAPULS C 11 fits into a small stainless-steel housing. It makes the measurement setup inconspicuous, protecting it against vandalism and theft.

Conclusion and outlook

Eylenbosch is convinced that the need for additional measuring points will increase. Expanding the sensor network is not a problem. A new level measuring point can be implemented quickly and easily at any time and integrated into the existing network. Once the level measurement module is installed, the instrument goes online automatically.

The administrator must only fill out a few fields in a digital activation form beforehand. All subsequent measurement data is automatically transferred to the database continuously. This ensures that the level data becomes quickly available on the data platform.

For more information, visit www.vega.com/