T3 - NETWORK OPTIMISATION AND CUT-DOWN OF AQUIFER ABSTRACTION

Actions

3.1 Hydraulic modelling & zoning - By means of hydraulic analysis & network modelling followed by zoning layout. Flow/pressure measurement devices are installed on the sample points. Measurements take place including one day of high and one of low consumption; a typical data collection interval starts on Friday and finishes on Tuesday when instruments are removed. Each measurement concerns 15 Km of distribution net (average).
The network of flow and pressure measurement instruments on the sample points without alteration of the existing dynamic equilibrium allow to get a true image of each zone with 5 minutes time resolution. The data so collected feed the hydraulic model. Comparison with minimum nightly flow allow to characterize each net portion and to spot candidate leaking sectors. On this basis the design of the active monitoring and control systems will be done next.
3.2 Procurement of control devices   - procurement process will be conducted bearing in mind exemplarity in the application of the 18/2004 Directive principles, also in terms of simplification and timeliness.
3.3 Regulation devices installation - After procurement of relevant devices, the installation of flow and pressure monitoring and control  systems will be conducted. Because pressure and time before repair (MTBR) greatly affect the impact of leakages, next step is to lower pressure to the optimal level for each sector. In so doing we will also prevent that fixing a known leakage the problem will be exported to an unknown point.
3.4 Leakage detection & repair -  Leakage detection – based at first on out-of-range flow data – is then refined by means of correlators to locate the position of the leak and acoustic leak sounding systems to confirm and precisely spot the position of the water leak.
3.5 Flow and pressure optimisation  The leakage detection data allow a preliminary pressure/flow regulation/optimisation before repair. After each repair the process is repeated. During field operations, both detection and repair, real-word data are gathered and entered into the model (e.g. actual pipe section, roughness data).
3.6 Model calibration -This action implies tuning the model (the used software is EPANET) with real data, and deriving an approach for progressively increase the adherence of the model’s parameters to the actual net status. Calibration will start with sensitivity analysis in order to chose optimisation parameters/methods and stop criteria. Iteration will follow until the stop threshold is met.
3.7 Outline ASAP Step 2 protocol - Action includes gathering relevat info, data and examples for the ASAP protocol and guidelines. The draft will then be issued for peer-to-peer verification with other experts. The revision of ASAP handbook first section based on feed-back will also be done.