Supply network efficiency: Saur solutions for improved performance
The Grenelle 2 environmental legislation introduced on 12 July 2010 sets targets for reducing the abstraction of water from the natural environment. Those targets were defined more accurately in the subsequent ministerial order of 27 July 2012. Abstraction of this type is subject to a fee payable by the water supply company, which is doubled if the detailed description of supply networks and/or the action plan to reduce water losses have not been prepared and submitted within the deadline set. These action plans are required where efficiency falls below a defined threshold, which varies from 65% in rural areas to 85% in urban areas. The replacement of supply networks may be the responsibility of the local authorities that own them, but Saur nevertheless has an advisory role to play in terms of infrastructure management. Saur is responsible for abstracting more than 700 million m3 of water from the natural environment every year, and has the technical solutions and innovative organisational structures required to provide a clear overview of the network now and in the future.
Organisational structure: our Operations Control Centres (OCCs)
Our Operations Control Centres provide a real-time overview of network and facilities status using sophisticated remote monitoring systems. With geolocation to pinpoint operator locations, and a job-specific expertise unit, they centralise the scheduling of maintenance and repair operations, analyse incident causes, and optimise the availability of all human and technical resources. The result is improved responsiveness and shorter response times.
All OCCs use secure, ‘private’ cloud computing to store data and share them online with our customers in real time.
Technology: making networks smart
Supply networks are divided into sectors using valves and meters at strategic points to give us accurate data on the actual volumes of water being supplied to each district. Used in conjunction with acoustic detectors for preliminary leak location, sectorisation is the most effective way of monitoring systems to detect water losses and take prompt remedial action.
Since sector control valves provide effective regulation of pipeline pressures, pressure can be reduced and regulated to contain leakage rates directly.
These systems and procedures are used by Saur to conduct criticality analyses which, combined with the performance targets set by agreement with the local authority, can then be used to define a pipeline replacement plan. This methodology is underpinned by multi-criteria estimation of risks using a variety of data, including pipeline material, diameter, average pressure, failure history, land use and even road traffic volumes.
Results and figures
- Between 2007 and 2011, water losses were cut by 700,000 m3 in Brive (Corrèze, 50,000 residents and 338 km of supply pipelines) delivering a 7-point gain in efficiency
- Between 2009 and 2011, water losses were cut by 21% in Gdansk (Poland, 400,000 residents and 1,000 km of supply pipelines)
- A 35% reduction in night flows (leak indicators) in Surgères (Charente-Maritime, 6,000 residents and 88 km of supply pipelines)
- Between 2010 and 2012, a 9-point gain in efficiency in Rophémel (Côtes-d’Armor, 9,000 subscribers and 433 km of supply pipelines)