Sustainable management of water also requires minimising losses on distribution networks, with all operational Group Companies in the water area involved. Again in 2021, as in the previous year, there was intensive activity to identify leaks, quantified as described in chart no. 56, in order to recover the greatest possible quantity of water. In particular, the dividing the network into water districts makes it pos- sible to optimise operating pressures, reducing losses, with targeted searches in the field in the most critical districts. With greater control of the individual parts of the network, it is possible to reduce losses, promptly identifying them or picking up on other anomalies.
Chart no. 56 – Water loss accounting model
NOTE: the image refers to the model of the International Water Association.
Overall, to date, Acea Ato 2 has created 581 measurement districts for over 11,500 km of distribution network. The activity consisted of surveys, flow and pressure measurements, map production, user analysis and water balancing, creation of measurement stations, installation of shut-off and adjustment elements, mathematical modelling and searches for leaks. The results of efficiency actions were imported into the GIS systems. In addition, 2021 saw optimisation of the quality of process measurements, through verification and calibration of meters installed on sources and drinking water plants, and progress in survey activity and georeferencing of networks. The actions implemented enabled a reduction in water-loss volumes of more than 13% compared to 2019147.
Thanks to efforts to improve the efficiency of metering and to com- bat illicit use, at Acea Ato 2 the overall losses for the year fell to about 39.8% (they were equal to 44.7% in 2019). Furthermore, in line with the downward trend of the previous two years, total losses on the Rome network were down by 28.6% (29.5% in 2020 and 34.2% in 2019).
In 2021 Acea Ato 5 completed district planning for the networks of nine new municipalities. In addition, efficiency was improved for dis- tricts previously created in order to rebalance operation of the net- work and optimise the distribution service. The Company has cre- ated 97 new districts covering 520 km of network. Active control of pressures has continued, with installation of meters, reducers and flow-control valves at strategic points, with the goal of improving management of flows into the zones managed, reducing differences between daytime and night-time pressure levels. In 2021, 31 water pressure control valves were installed.
On the supply network, as planned, 137 km of network was inspected, with the addition of further stretches identified after study of the single-line diagrams performed during the year. No significant leaks were identified and approximately 30 km of network was restored: this activity led to cartographic reconstruction, during the year in question, of 925 km of network. On the basis of these works, 2021 losses were slightly lower, at approximately 67% (68% in 2020) of resources issued to the aqueduct system, and volumes lost were down 17% compared to 2019.
At Gesesa during 2021 a Recovery Plan was launched for water resources in the city of Benevento, which involves replacement of damaged pipes, implementation of remote control technology, application of a system to reduce water leaks and reduction of operating pressures on the network. Losses in the year were 57.8% of water issued to the aqueduct system (59.4% in 2020). Actions will continue in 2022, also involving other Municipalities.
AdF conducted intensive activity to search for system leaks on its own water networks. In total in 2021, the Company inspected approximately 3,000 km of distribution network and created districts covering 300 km of network, with 115 of this on networks not yet subject to monitoring of night-time minimums. This enabled a decrease in the average size of districts and district planning for approximately 90% of the distribution network, with 87% coverage of total users. Monitoring was launched for a portion of the water distribution network in the town of Grosseto using a fixed leak-detection system, with a noise logger. The activities launched by AdF have allowed a significant reduction in the volume of water lost, achieving a reduction of 13% compared to 2019. Action taken en- abled a reduction in losses, from 42.5% in 2020 to 39% in 2021.
In 2021, there was also continuation of three pilot studies for experimentation of new innovative technology applied to searching and detection of water leaks. The first of these, involving satellite searches on 600 km of network, gave good results both in terms of the number of leaks detected and the speed of detection. The second, based on a predictive methodology that identifies the areas most at risk of breakages, gave good results in the city town of Grosseto, enabling definition of 23 critical areas, in which 16 hidden leaks were identified. The third is a study based on reducing network pressure, to guarantee the minimum pressure required for maintenance of optimal operation at the critical point, which will be combined with analysis on the reduction in CO2 emissions due to reduced pumping to issue water at the tank upstream of the network.
In 2021 GORI launched various actions in the municipalities of Nola, Angri, Nocera Inferiore, Castellammare di Stabia, Gragnano and Torre Annunziata, including verification and full mapping of networks for GIS representation and activities aimed at water-network optimisation148. Tradition leak-detection activity also continued for the remaining municipalities in the District. Overall, GORI conducted searches for leaks on 1,676 km of water network, of which 1,118 km was analysed using “systematic” searches for leaks, and 558 km on the basis of “faults”. In 2021, eight pressure regulation valves were installed and repair work was performed on approximately 141 km of water network. The combined action of the strategies enabled a reduction in volumes lost of approximately 14% compared to 2019. See the Environmental Accounts for details on individual water balances.
147The reference year is 2019, for all Companies, in accordance with the goals set out in the 2020-2024 Sustainability Plan.
148For example, the phase of planning optimisation of network includes construction of mathematical models of the network, calibration with smart mobile instrumentation, planning
of optimal districts, pre-localisation of leaks and checks in the field, smart leak detection guided by the mathematical model, identification of stretches to be replaced and
definitive planning with related preparatory activity..