Syndicat du Bas Languedoc — From 3 months to 1 day to schedule its work

850 km of network, 5 people: the challenge of maintaining 90.90% efficiency

The Syndicat Intercommunal d'Adduction d'Eau des Communes du Bas Languedoc (SBL) is a historic player in drinking water in Hérault. Founded in 1946, it serves 27 municipalities — including Sète, Marseillan and Frontignan — for 220,000 permanent inhabitants and more than 500,000 in summer. Its network totals 850 km of pipes: 175 km of adduction and 650 to 680 km of distribution. The syndicate only has jurisdiction over drinking water.

The SBL is a light structure: 5 people, including Marc Coustol, territorial engineer and director of the union since 1999. The Cabinet Merlin design office provides technical studies. Since January 1, 2022, the operation has been entrusted to a SEMOP “Eau du Bas Languedoc”, 40% owned by the syndicate and 60% by Suez.

The efficiency of the network at the end of 2025 was 90.90%. But that is precisely where the challenge lies: the vast majority of the pipes were built after the war and are reaching the end of their life. The challenge is not to improve performance, but to maintain it over time in the face of aging assets and successive drought crises in the Mediterranean region.

Marc Coustol, Director of the Syndicat du Bas Languedoc: “Gaming is about network performance. You should know that all the networks were created, at least a large part, after the war. So we will start to reach the end of the life of everything that is network, everything that is connection. Tomorrow's challenge is to be able to maintain the network performances that we have today. I don't even say improve, I say maintain.”

“Undrinkable” Excel files to manage 5 million euros of work per year

With a renewal budget of 4.5 to 5 million euros per year and a renewal rate target of 1.2% by 2028-2034, the SBL needed to plan its investments accurately. However, the existing tools were no longer keeping up.

Before Leakmited, work programming was based on Excel spreadsheets. For a 650 km network, these files had become unmanageable. The development of a preliminary draft — analysis, decision, arbitration — took 3 to 4 months. A delay that is incompatible with the responsiveness expected by elected officials and the planning needs of the union.

Marc Coustol: “We had archaic tools. You had to have a tool that removes a bit of everything you are used to seeing. We were working at the beginning when I came up with Excel tables. When you have 650 km of networks, the Excel files at the end of the day were undrinkable.”

In addition, the SBL wanted to have its own decision-making tool, independent of that of its farm company, to maintain total freedom in the choice of work.

Marc Coustol: “We wanted to detach ourselves from the tools of our farming society in order to be able to have the free choice of what we wanted to achieve in construction.”

An innovative discourse: “If you can't find the leaks, you don't get paid”

The first contact took place in Narbonne, after a conference where Leakmited presented his company. What first caught Marc Coustol's attention was the business model of leak research — a commitment to the result. Then the discovery of the digital twin opened up a new perspective: a heritage programming tool that did not exist at the community level.

Marc Coustol: “You had a speech that interested us: if you don't reach a certain level of performance, you don't get paid. It was this speech that was a bit innovative in what we heard.”

Marc Coustol did not know the concept of a digital twin before he met Leakmited. The union started with an initial contract of 3 years, which was then renewed twice a year, for a total of 5 years of collaboration.

3-4 months of preliminary draft reduced to a decision during the day

The Twin digital twin has been deployed across the entire 850 km network. It is used by Marc Coustol and Cabinet Merlin — the only two users — to build renewal plans. Use is regular, every month, with a variable frequency according to the requests of the town halls: 1, 2 or 10 times per month. Election periods generate more intensive use to prepare plans to be presented to new elected officials.

Marc Coustol: “It is a tool that goes very, very quickly in the requests that are asked of it. The response is almost instantaneous. So we save a lot of time on work planning, which is huge. It's huge.”

The tool has evolved considerably over the 5 years of collaboration. At the beginning, changing a single parameter required creating a new scenario and re-entering everything. Today, it is possible to intervene in an existing scenario, adjust parameters and work on a single municipality without recalculating the entire network.

Marc Coustol: “The elected officials tell us that's it, I want to know in the town of X if I renew that the PVC of 70, what does it mean? With your tool, it's very, very easy to do that now and we have very quick results.”

Marc Coustol: “The time for us to make a preliminary draft, to decide, to look, all this took 3-4 months. There, during the day, the decision is made.”

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3-4 months → 1 day: decision time on the programming of work

2-3 minutes to generate a renewal scenario over 850 km of network

5 yearsof continued renewed collaboration with Leakmited

4.5 to 5 M€/yearof controlled work with the digital twin Twin

“We move three parameters and it gives the reproduction 2-3 minutes later”

Marc Coustol: “It's reaction time. You change three parameters on a scenario and it gives you the feedback 2-3 minutes later. When you run on 850 km of network... When you run a town, it's time to get up and go get some coffee.”

Independence, speed, sustainability: 5 years of renewed collaboration

The main result of the collaboration is not improved performance — SBL was already performing at 90.90% before Leakmited. The value provided is based on three axes.

The time to decide on the programming of work, radically reduced. Marc Coustol describes a transition of 3-4 months from a preliminary draft to a decision taken during the day. Renewal scenarios are generated in 2-3 minutes over the entire 850 km of network.

Independence in investment choices. The SBL builds and arbitrates its own renewal plans, without depending on the tools of its farm society. It is a strategic lever for a community that invests between 4.5 and 5 million euros per year in renewal, with a target of 6.5 to 6.8 million euros per year between 2028 and 2034.

A lasting collaboration of 5 years, renewed. After an initial contract of 3 years, two annual renewals followed.

Marc Coustol: “I think you are still a step ahead of the competition. I have not heard of a tool similar to yours. On some features, there are some that are similar, but having a complete tool, no, I haven't seen anything work yet.”