Local authorities: confronted with scarcity, how can you preserve your water resources?

Behind the illusion of a country blessed with abundant rainfall lies a less comfortable reality: the renewable water resources available in our territory have decreased by 14% in just 20 years, an alarming finding directly linked to human pressure and the effects of climate change. The consequences are clearly visible: in 2019, only 45% of water bodies were considered to be in good ecological condition, and every year, more than a hundred water catchment points are forced to close due to insufficient quality.

But that's not all. A significant proportion of the water collected for treatment and distribution never actually makes it to users' taps. It is estimated that approximately one billion cubic metres of water are lost each year in pipes in France. To put this figure into perspective, it represents the equivalent of the annual consumption of approximately 18 million inhabitants. It's as if New York City were drawing water just to let it all escape along the way.

These massive losses are reflected in a key indicator: the average efficiency of drinking water distribution networks, which stands at around 80%. In other words, out of every 5 litres of water injected into the network, 1 litre is lost before it reaches the consumer. While achieving 100% efficiency is unrealistic, sources indicate that many local authorities could aim for a target of 80 to 90%. Currently, only 10% of users in France benefit from a service with an efficiency rating above 91%.

This situation is exacerbated by the age of our infrastructures: half of France's drinking water supply networks were laid more than 50 years ago. Like any ageing infrastructure, these networks are more prone to failures, leaks and breakages.

These figures are not mere statistics; they reveal the growing vulnerability of our water supply system and highlight the urgent need to take action.

With climate change and overexploitation of resources, some water catchment points are already seeing a sharp decline in their flow rates. In some areas, groundwater is drying up faster than it can be replenished.

A striking example: In France, according to the French geological and mining research agency (BRGM), more than 60% of groundwater tables were at a moderately low to very low level in 2023. And during the droughts of 2022, dozens of municipalities had to be supplied by tanker trucks due to a lack of local drinking water.

Without rational management, certain local resources may simply disappear, forcing us to seek more costly and less sustainable solutions, sometimes scores of kilometres away.

The LOG09V4 wireless data logger from Ijinus, connected to a CNR sensor, can accurately monitor groundwater levels, providing crucial information for hydrogeological knowledge of the area. This solution helps guide decision-making.

The quality of freshwater resources is threatened by multiple sources of pollution:

Agriculture: nitrates and pesticides

Industry: heavy metals and solvents

Urbanisation: domestic effluent and hydrocarbons

When these pollutants reach water catchment areas, it causes two major problems:
- Treatment costs spiral to maintain water safe for drinking.
- If pollution is too severe, certain resources simply become unusable and must be abandoned.

According to the French Water Agency, treating lightly polluted water can cost up to five times more than water that is naturally of good quality.

Ageing water networks leak, and not just a little. Detecting and pinpointing leaks is a major challenge because, on average, one in five litres is lost before it reaches the tap (Observatoire des services publics d'eau - Observatory on public water and sanitation services in France). These losses force local authorities to produce and pump far more water than is needed, resulting in high energy costs.

In order to catch up on maintenance and modernise infrastructures, it is necessary to tackle what is known as an unequivocal “investment ladder”.

Estimates suggest that an additional 4.6 billion Euros per year will be needed to upgrade drinking water supply, collective sewerage and rainwater drainage networks. An impressive figure, but one that is essential to prevent the energy, environmental and financial costs from becoming unbearable.

Prolonged droughts, heat waves, accidental pollution (e.g. chemical spills or industrial incidents): all these events can jeopardise water supplies if the networks are not robust and there are no alternative sources available.

In 2022, French prefectures had to issue more than 1,000 water restriction orders, affecting household, agricultural and industrial users alike.

By taking a proactive management approach, it is possible to plan ahead, diversify sources, create interconnections between networks, and avoid service disruptions at the worst possible moment.

Regulations governing water quality and network performance are becoming increasingly stringent.
For example, the "fuites" or "leakage" decree requires local authorities to achieve a minimum efficiency level for their networks. If this threshold is not reached and no action plan is implemented, fees may be increased, placing an even greater burden on local finances.

Therefore, water utilities no longer have a choice: they must adapt to avoid accumulating penalties, additional costs and loss of performance.

Last but not least, we must not forget the human aspect. When residents notice inconsistent water quality, frequent outages, or a steady increase in their bills without any visible improvement, confidence in the public service quickly erodes.

According to a survey by French consumer organisation UFC-Que Choisir, 35% of French people already believe they pay too much for their water. If they do not see the benefits of the investments made, their discontent is likely to increase, which could lead to a tense social climate.

Opting for proactive and sustainable water management is much more than simply ticking a regulatory box:

It's about preserving a precious resource for future generations.

It's about avoiding soaring costs in the long term.

It's about guaranteeing a high-quality public service that lives up to citizens' expectations.

And above all, it's about preparing our regions to cope more effectively with the crises that lie ahead.

The first crucial step is to acquire in-depth knowledge of the water networks. Imagine your water network as a complex human body: to take care of it, you need to know its anatomy, the history of its health and monitor its vital signs. For a network, this means knowing the precise location of the pipes, the materials used, their age and their maintenance history. This data is essential to anticipate weak points and prevent failures.

As well as physical inventory, it is essential to monitor parameters that can affect networks, such as the actual quality of the water, which influences internal corrosion, soil quality for external corrosion, along with pressure and temperature variations. Accurate mapping coupled with pressure, flow and water quality data provides a crucial big-picture.

This in-depth knowledge makes the "invisible visible", i.e. areas prone to leaks or breaks can be detected before they become major problems, thereby facilitating the implementation of targeted preventive measures.

The Blue LP logger, from Ijinus, is a data logger equipped with flow and pressure sensors. It can be used to monitor networks (tracking transit volumes, adjusting volume/pressure indicators), increase their performance and efficiency, minimise water losses (identifying and taking action in specific areas) and preserve resources.

Today, local authorities and water managers have a host of innovative tools at their disposal to monitor, maintain and improve the performance of networks. These intelligent, technology-based solutions make it easier to detect problems, anticipate failures and prevent costly leaks. The main innovations used are as follows:

Acoustic sensors to detect leaks

Sensors placed directly on the network continuously listen to the noises transmitted through the pipes. An unusual noise, such as a hissing sound or a suspicious flow, may indicate a leak.

BiDi LTE, a pre-locator from FAST, can be used as a water network monitoring system.

Adapt management practices in line with water quality

Water quality can have an impact on how quickly pipes wear out. For example, water that is too acidic or too hard can cause materials to deteriorate more quickly. By analysing these parameters, managers can fine-tune their strategy (treatments, choice of materials) to extend the service life of networks.

Manage pressure to prevent wear

If the pressure in the pipes is too high, it increases the risk of cracks and leaks. With modern systems, this pressure can be dynamically regulated to suit the needs of the moment, thereby reducing wear and improving efficiency.

Example: In some urban areas, a slight reduction in pressure has reduced leaks by 10–15% without compromising on quality of service.

To monitor pressure in drinking water networks, Ijinus has designed the Blue LP logger. It can be used to conduct diagnostics and monitor key sectorisation data (pulse counting, Modbus flow measurement and pressure). A major advantage for monitoring networks, boosting their performance and efficiency, and minimising water losses.

Use satellite data to identify anomalies

Satellite images, combined with other ground-based data, can reveal subtle signs on the surface, such as areas with abnormal moisture levels, which may indicate a hidden leak.

Accurate diagnostics, even without digging

With new technologies, it is now possible to assess the condition of pipes without necessarily having to open them up. Samples taken can be analysed in the laboratory to detect signs of wear, whereas non-invasive techniques, such as acoustic signals, can be used to accurately map the health of networks.

Artificial intelligence to identify potential problems

AI is revolutionising water management. By analysing vast amounts of historical data on interventions, the results of inspections and real-time measurements, algorithms can predict where and when leaks are likely to occur. By doing so, interventions can be prioritised, work can be planned, and increasingly costly emergency repairs can be avoided.

Interesting fact: A European study estimates that the combined use of sensors, satellite data and AI could reduce water losses in networks by 25 to 30%, while also lowering long-term maintenance costs.

By combining these approaches, it is possible to significantly improve network knowledge and effectively reduce the risk of failures and breakages, thereby taking action at the right time, in the right place, and at the best possible cost.

Monitoring and diagnostics lead to action. A whole host of technologies and methods are needed to curb leaks and slow down the ageing of infrastructures.

This includes:

Network sectorisation for more effective control and pinpointing of losses.

Active leak detection and repair. Measuring tools positioned on the networks (pressure, flow and noise sensors) and data analysis and visualisation tools enable anomalies to be pinpointed with great accuracy. Independent, communicating systems provide continuous monitoring.

Using connected valves to remotely control the network and detect abnormal consumption.

Renovating networks, including trenchless methods. Techniques such as pipe lining enable existing pipes to be renovated cost-effectively and in ways that are environmentally friendly.

Expert simulation tools to predict the future condition of pipes based on diagnostics and historical data.

It is essential to draw on the expertise of specialists in the design and manufacture of reliable equipment for the construction, maintenance and repair of networks if their long-term efficiency is to be guaranteed. The Claire Group also offers diagnostics, monitoring and control systems to improve overall performance.

Water does not stop at administrative boundaries. Effective management must transcend sectoral approaches (drinking water and sewerage) in favour of an integrated, territorial and adaptive management approach. This includes managing the "large cycle" of water, such as managing aquatic environments and flood prevention (GEMAPI - Gestion des Milieux Aquatiques et Prévention des Inondations - management of aquatic environments and flood prevention), soil de-impermeabilisation, and management of rainwater. Initiatives such as regional water management projects (PTGE) encourage this collaborative approach across river basins.

The necessary investments are substantial, but funding solutions exist. For example, the Banque des Territoires has pledged its support to local authorities with dedicated programmes, in line with the government's Water Plan. Tools such as Aqua Prêt offer very long-term funding (up to 60 years for certain projects), potentially covering 100% of the cost of water-related projects, from small to large cycle. Engineering tools and platforms such as aquagir.fr also help to structure projects and identify available funding.

By combining these actions – improved knowledge of networks, using technology, renovating, integrated management and raising funds – local authorities can not only reduce water losses and improve the performance of their networks, they can also bolster their region's resilience to the challenges posed by water.