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MAP Sewer – automated creation of simplified models

New MAP Sewer capability speeds up the creation of the simplified sewer network models that we use to deliver near real time predictive modelling of the sewer network.

The creation of the simplified hydraulic models in MAP Sewer is a process that we have been working to improve so that we can rapidly create new models for new catchments. We have now automated the process of creating the main simplified model, and all the relevant geometries, from the detailed GIS layers that make up the ‘standard’ detailed models used by most water companies.

The objective of this work is:

  • Generate the MAP Sewer model inputs from the detailed model
  • To do this in an automated way using a combination of QGIS and PYTHON scripts
  • The methodology includes:

  • Derive location of Pumping Stations, Combined Sewer Overflows, Detention tanks, Weirs and Sluices
  • For each Pumping Station, use QGIS flow trace to identify the upstream conduits
  • Identify the sub-catchments associated to these upstream conduits
  • Dissolve the sub-catchments into one large sub-catchment
  • Aggregate the key sub-catchments properties
  • Calculate the main trunk sewer path and aggregate sewer length, gradient and diameter
  • Create the MAP Sewer nodes
  • The process takes several hours to run and the outputs are:

  • MAP Sewer configuration files. These are CSV files for each geometry. I.e. Pumping Stations, Combined Sewer Overflows, Detention tanks, Weirs and Sluices
  • One sub-catchment file containing all the dissolved sub-catchments. this is a KML file
  • Once this is done then we can add some of the pumping attributes to the Pumping Station and Detention Tank geometry files and then load all the files into MAP Sewer from the dashboard. MAP Sewer then creates the geometries in a few minutes and the whole catchment is calculated in 20 minutes – this includes over 2 years of historic data all at 5 minute periodicity. We can now start to validate the model and to feed it with real time and forecast rainfall data.