In 2008, Yorkshire Water implemented Crowders Netbase Water Management System to support the reporting and management of network leakage and pressure. Hydraulic model analysis has been a particular area where improvements in data confidence has seen significant gains in efficiencies. Initialising the Netbase HM Manager application and developing new working practices using a trial model delivered the following benefits:
Reduced effort in the model construction / build process
Improved accuracy within the resulting models
Consistent methodology across model build process
Cost-effective model maintenance enabled by the standardisation
The gains demonstrated through the trial, led to Crowders partnering with Arup, one of the framework partners on Yorkshire Waters Consultancy Services Contract, to deliver several models using HM Manager and the newly developed processes. The activities on the project included defining the model extents, validating network assets and associated data, constructing the hydraulic model, conducting supply site visits, developing and executing a field test plan, performing the field test, calibrating the model and producing a comprehensive model report.
Yorkshire Water recognised the success of the HM Manager initialisation, and the newly established model build processes. As a result, they refined their modelling strategy to leverage these improvements for the AMP7 investment period (2020-25). Their strategy stipulated that all new hydraulic models were to be constructed using HM Manager and that existing models not scheduled for renewal were to be migrated into HM Manager.
Under Yorkshire Waters AMP7 Modelling Framework contract, Crowder Consulting were awarded 12 hydraulic models. The models have been built using HM Manager and the processes that were established under the previous framework contract.
The model extents were defined collaboratively with Yorkshire Water to ensure all relevant
infrastructure and operational areas were included. Key infrastructure assets such as Service Reservoirs, Pumping Stations and Control Valves were identified for data gathering. A network
schematic was drawn to show asset connectivity, the upstream network, areas in the model and zonal boundaries. This enabled meter balances to be performed to flag anomalous and missing data, for which enabling works were raised.
Models were constructed in HM Manager, incorporating validated network data. Trace and connectivity tools were employed to assess data integrity and reveal anomalies, which were addressed. The resolution steps consisted of drawing missing assets, updating asset connectivity and asset flow directions, completing pipe and property assignments, generating elevation data, adjusting internal pipe diameters and pipe roughness coefficients.
An initial demand analysis was carried out and applied to an initial model. Discrepancies between the observed network flow and derived consumption data were investigated and resolved in consultation with the client.
Existing model control data were reviewed and migrated where applicable, with previous calibration assumptions applied where appropriate. The model was then exported from HM Manager into InfoWorks WS Pro to perform a limited calibration exercise. Permanently monitored data was used to compare against the modelled flow, pressure, and level simulation results to ensure they were within acceptable tolerances. This initial model was shared with Yorkshire Water for internal review and sign-off.
A model field test plan was produced detailing the sites requiring monitoring in-line with the client’s specification e.g., pressure logger density of 1 per 250 properties. Yorkshire Water reviewed and amended the plan, and further enabling works were arranged to ensure sufficient monitoring coverage.
Logistical planning followed, this included completing Health & Safety documents, issuing notifications, obtaining permits, preparing equipment, and producing field test documents.
Flow and pressure loggers were deployed at key locations, with supply site visits and intermediate checks carried out where required. Following a 7-day monitoring period, data was retrieved, and pressure logger locations were surveyed for elevation data.
The model calibration phase involved several key activities:
The field test data was processed and reviewed both qualitatively and quantitatively to select a calibration day.
Comparative profiles were generated for the calibration exercise to assess model fit.
Falling head analysis led to identifying anomalous data that was addressed by applying offsets, correcting elevations, or excluding the data.
Flow balance analysis identified anomalous data that was either corrected or excluded.
Base demands were generated and then a demand analysis conducted for the calibration day to derive the demand profiles.
Operational controls were applied to the models based on the information collected in the previous phases.
Simulations were run for the calibration day and the models calibrated to meet the following tolerances: flow (±5%), pressure (±1m) and level (±100mm). Any exceptions were documented for further resolution.
The final calibrated model, along with a comprehensive model report, were submitted to Yorkshire Water for review and formal sign off.
The project delivered high-quality, calibrated hydraulic models that provided Yorkshire Water with a reliable tool for network analysis and decision making. The systematic approach to data gathering, validation, and field calibration ensured model robustness and accuracy. Now integrated within Netbase HM Manager, Yorkshire Water can now efficiently maintain the models and update them by targeting specific areas for localised field testing. This enhances operational efficiency and helps ensure the models remain calibrated and fit for purpose.