3.1.2. Layers explanation Main layers

QGEP is constructed around two main layers :

  • Wastewater structures qgep_od.vw_qgep_wastewater_structure

  • Reaches qgep_od.vw_qgep_reach Wastewater structures qgep_od.vw_qgep_wastewater_structure

Main layer for manholes, special structures, infiltration installations, discharge points (and wastewater treatment plant (wwtp) structure). Creating a new record in this layer always creates a new wastewater structure, a new cover and a new wastewater node. In the edit form, you have access to a lot of the related tables (e.g. structure parts, maintenance events).


Even if there are several covers or wastewater nodes, there is just one point for every wastewater structure in this layer. By default, the position of the wastewater node created first is used as the point coordinate.


Do not export this point coordinates as covers. Use the layer vw_cover for this. Reaches qgep_od.vw_qgep_reach

Main layer for line-wastewater structures (channels). Creating a new record in this layer always creates a new reach and a new channel. In the edit form, you have access to a lot of the related tables (e.g. structure parts, maintenance events).

../../_images/schema_vw_qgep_reach.jpg Wastewater Structures Wastewater Structures Details qgep_od.wastewater_structure

This layer shows and enables you to edit the detailed geometries of wastewater structures. You can add a new detailed geometry using the layer vw_qgep_wastewater_structure action called digitize detailed geometry.

See digitizing detailed geometries for more information. Structure Parts qgep_od.structure_part

Cover is the only structure part with a point-geometry itself. All other structure parts are just linked to their wastewater structures and should by only edited by the main layers (vw_qgep_wastewater_structure and vw_qgep_reach). Covers qgep_od.vw_cover

Use this layer to change the situation of some specific cover (and not the whole wastewater structure) or to add a new cover to an existing wastewater structure. You can add an additional covers in the covers-tab of the vw_qgep_wastewater_structure too. Additionally, use this layer to show the detailed position of the covers (e.g. in network_plan or pipeline_registry) or to export the cover positions situation_geometry. Channels qgep_od.vw_channel

The channel-class has no geometry and is therefore mostly changed in the vw_qgep_reach layer. Organisations qgep_od.organisation

od_organisation contains the organisation that you can select in attributes like fk_dataowner, fk_operator, fk_provider, fk_owner, etc.


This table is today a little bit hidden in the wastewater_structures group (but it is not only related to wastewater structures).

If you want to export data to the VSA-DSS 2015 model, you have to manually add the relation to the respecitve subclasses of organisation by adding the respective obj_id’s in the subclass tables, e.g. municipality, else the export will give an error message. For export to SIA405_Abwasser and VSA-KEK this is not needed.


Alternative: You can use vw_organisation instead of od_organisation. vw_organisation has the subclasses integrated and must be loaded manually to the project. Maintenance events qgep_od.vw_qgep_maintenance

Maintenance events can be created through the view qgep_od.vw_qgep_maintenance.

These maintenance events are used in the maintenance tabs in the main tables. They can be linked to one or several wastewater structures.

See editing maintenance events for more information. Value Lists qgep_vl.*

These value lists are defined in the VSA-datamodel. Do not change. Hydraulic Wastewater nodes qgep_od.vw_wastewater_node

Use this layer to change the situation of one selected wastewater node (and not the whole wastewater structure) or if you want to add a new wastewater node to an existing wastewater structure. You can add additional wastewater nodes in the wastewater nodes-tab of the vw_qgep_wastewater_structure too. Overflow tables qgep_od.vw_qgep_overflow

These tables are connected to wastewater nodes. In the project-file template (Version 8.0, 4.6.2020) are no relations defined for these tables. Topology Nodes qgep_network.node and segments qgep_network.segment

These two layers are used by the qgep-extension for the profile and the network-following functionalities. Use the qgep_network.segment layer to show the flow direction, if you use a markerline (filled_arrowhead) as symbol.

See connect wastewater network elements for more information on how to create and maintain a good Topology. Catchment qgep_od.catchment_area

Main layer to digitize and edit the catchment_areas.