Discover the Acea Group online 2019 Sustainability Report

Water losses

Sustainable water management includes the issue of limiting leaks from distribution networks (see also Quality in the water segment in the chapter Customers and communities). During 2019, as in the previous year, the water companies – in particular Acea Ato 2 – continued their intense search for leaks in order to recover as much water as possible (see the box for details). Furthermore, Acea Ato 2 established a unit dedicated to the protection of water resources and the implementation of initiatives aimed at reducing losses.

Together with the search for hidden leaks, Acea Ato 2 continued to divide the network into districts not connected to each other and with measured inputs, which enables the optimisation of their management, facilitating and making repairs more timely and reducing their frequency. Dividing the network into water districts makes it possible to optimize operating pressures with an immediate advantage in terms of reducing lost volumes, facilitating targeted searches for leaks in the most critical districts.

To date, overall approximately 6,200 km of distribution network have been studied and 300 measurement districts have been created.

The activity consisted of surveys, flow and pressure measurements, map production, user analysis and water balancing, mathematical modelling and searches for leaks. The results of the study and efficiency actions were imported into the GIS systems.


As part of the work to divide the water network into districts, in 2019 approximately 520 flow and pressure meters were installed by Acea Ato 2 technical personnel in the water districts, which will enable the timely monitoring of new and hidden leaks in Rome and in the 12 municipalities concerned, the optimisation of piezometric quotas and the consequent reduction of lost water volumes. The district planning and installation of meters in the districts will progressively involve the entire territory managed by Acea Ato 2.

In 2019 Acea Ato 5 also developed the analysis of the water network (especially in the areas of Atina, Cassino, Castrocielo, Colfelice, Fiuggi, Frosinone, Morolo, Serrone, Sora, Strangolagalli, Roccasecca, Patrica, Sgurgola and Supino).).

In total, 148 districts were created, involving approximately 1,190 km of water network. In addition, a total of 140 leaks – of which 40 hidden – were identified with leak searches, mainly using acoustic systems. The division of the network into districts and installation of pressure reduction devices has made it possible to reduce network input volume121 by about 5%.

In the Sarnese-Vesuvian District, managed by Gori, numerous interventions were carried out to reduce water leaks, including the installation of pressure regulation valves, and several systematic leak search searches were performed along the water networks.

Moreover, the reclamation projects carried out on 66 km of water networks, distributed over almost all the municipalities of the District, enabled recoveries estimated at about 193 l/s.

In 2019 Gesesa further developed the division of water networks into districts by extending the reduction of pressures and setting the goal of progressively intervening on the network of all the municipalities managed. Following an analysis of the water networks, about 2 km of infrastructure was reclaimed.


NOTE The image refers to the model of the International Water Association.

In recent years, ARERA has intervened with several resolutions, introducing progressive changes to the process of calculating the water balance122. The new data, illustrated in detail in the Environmental Accounts123, has been prepared according to the new ARERA calculation method (Resolution 917/2017/R/IDR), also recalculating the previous two-year period, in line with the model of the International Water Association (see chart no. 49), which requires the assessment of water losses on the entire scope of the aqueduct system (and not only on the distribution network), including apparent losses.

Thanks to efforts to improve the efficiency of metering and to combat illicit use, at Acea Ato 2 the overall losses for the year fell to about 44% (they were equal to 47% in 2018). Furthermore, in line with the downward trend of the previous two years, the real losses of the “historical network” (Rome and Fiumicino) decreased to 31.9% (they were equal to 38% in 2018 and 41.5% in 2017), while the real losses on the distribution network of the entire OTA 2 decreased to 39.2% (they were equal to 44% in 2018 and 45.7% in 2017).

At Acea Ato 5 the losses in 2019 amounted to approximately 76% of the amount fed into the aqueduct system. It is expected that there will be a reduction in these losses as a result of a search for illicit users and the division of the networks into districts. See the Environmental Accounts for details on individual water balances.

Following the actions described above, Gori saw a reduction in global losses from 53.8% to 52.6%.

At Gesesa124 the losses of the year amounted to approximately 56% of the total fed into the aqueduct system.

121 The figure is not yet consolidated.
122 The loss assessment was carried out this year for the three-year period 2017-2019, according to Resolution ARERA 917/17 R/IDR. Until last year the losses were calculated according to the model specified in Ministerial Decree 99/97.
123 The water reports of the Companies active in Umbria and Tuscany, with consolidated net worth, can be examined in the chapter Water company data sheets and overseas activities.
124 Calculations of previous years according to the Arera provisions were not yet available for comparison at the time of publication.