6.4. Check SWMM File

The generated .inp file can be imported in SWMM GUI. It is likely that some errors will be raised. You will have to solve them (see hereunder a list of common errors)

You have to solve the errors in the order in which they appear in the report. Some errors are interrelated (i.e. a node in a conduit is not defined => the conduit is not imported => Undefined link error)

To fix an error you can search in the corresponding TWW layers in the QGIS project:

  • vw_wastewater_node for undefined nodes

  • catchment_area for subcatchment errors

  • compare if the number of exported nodes (in vw_junctions) are what you expect it to be.

  • Check if the function (manhole / special_structure) of wastewater_structure are all filled in

  • etc.

6.4.1. Common import errors

6.4.1.1. Missing status or _function_hierarchic (wn_function_hierarchic)

The catchment area is linked to node which is not exported or a reach cannot be drawn because of a missing node:

  • because of its status (abandonned etc.) or status is not defined (is Null)

  • the node is not connected (correctly) to a conduit

  • the node is secondary (the linked reach are secondary)

and therefore not export in the vw_junctions.

Check your data manually before the export if wastwater_structure.status is not empty. Check whether wastwater_structure._function_hierachic is filled in on Primary network nodes (PAA nodes).

For more details see related Github issue

6.4.1.2. Catchment area connected to secondary wastewater structure

Undefined Node (CHamtKnv00002706) referenced at line 20997:
[DWF]
CHamtKnv00002706      FLOW    0.0204074074074074      dailyPatternDWF

The catchment area is linked to a secondary wastewater structure

6.4.1.3. Missing discharge coefficients

Too few items at line 104:
[SUBCATCHMENT]
ch19ar68CA008855_ww_current   raingage@ch19ar68CA008855       CHamtKnv00001992        0.0276          19.4322613668305

The subcatchement discharge coefficients are not filled in. You can find them using sql:

select obj_id, fk_wastewater_networkelement_rw_current, discharge_coefficient_rw_current
from tww_od.catchment_area
where fk_wastewater_networkelement_rw_current is not null and discharge_coefficient_rw_current is null;

select obj_id, fk_wastewater_networkelement_rw_planned, discharge_coefficient_rw_planned
from tww_od.catchment_area
where fk_wastewater_networkelement_rw_planned is not null and discharge_coefficient_rw_planned is null;

select obj_id, fk_wastewater_networkelement_ww_current, discharge_coefficient_ww_current
from tww_od.catchment_area
where fk_wastewater_networkelement_ww_current is not null and discharge_coefficient_ww_current is null

select obj_id, fk_wastewater_networkelement_ww_planned, discharge_coefficient_ww_planned
from tww_od.catchment_area
where fk_wastewater_networkelement_ww_planned is not null and discharge_coefficient_ww_planned is null;

6.4.1.4. Missing population densities

ERROR 211: invalid number dailyPatternDWF at line 4288 of [DWF] section:
00000000WN006032 FLOW             dailyPatternDWF

tww_od.catchment_area.population_density_current or tww_od.catchment_area.population_density_planned are not filled.

6.4.2. Subcatchments and rain Gauges

If you want to attach every subcatchments to a single rain gauge, edit the file with SWMM interface:

  • Edit > Select All

  • Edit > Group Deletion > All Rain Gages

  • Create a new raingage

  • Edit > Select All

  • Edit > Group Edit

    • For objects of type: Subcatchment

      • Edit the property: Rain Gage

    • By replacing it with: Name of the new rain gage

To edit the rain serie:

  • Click on Time Series

  • Double click default_tww_raingage_timeserie

  • Edit the serie