Overview

Often, new water models are constructed by first importing much of the network data from a GIS data source such as a geodatabase. However, GIS data is frequently updated as more is learned about the system, new facilities are constructed, or old facilities are abondoned, for instance. Therefore, it is often necessary to update the water model with new information from GIS as it becomes available The ModelBuilder tool in WaterCAD/WaterGEMS provides the means to do this.

With ModelBuilder, you can import, create, and update both a GIS or other databases and water model files. The process described in this TechNote will demonstrate how to add new elements, as well how to update existing elements in the water model from from a geodatabase file.

This TechNote is a continuation of "Building A Model Using Model Builder;" however, it can be used independetly. The procedure described here uses a geodatabase as a source of modeling information and WaterGEMS as the modeling software. However, ModelBuilder supports a variety of other data source formats, and analogous steps can be followed in other Bentley modeling software applications such as SewerGEMS, SewerGEMS Sanitary, StormCAD, and SewerCAD.

Note: You will only be able to establish a connection to an ArcGIS geodatabase data source if you are running WaterGEMS (or SewerGEMS, or SewerGEMS Sanitary) within the ArcMap interface. However, other data source types are available when working within other interfaces (Stand Alone, Microstation, or AutoCAD) or when using non-"GEMS" software.

For this example, we will assume that the GIS data source has been updated with a new well.  Also, the existing discharge line has been abandoned and replaced with a new 20" line. So, for this update, ModelBuilder should do the following:

1. Add the new well system , which includes adding:
   1. the new well as a reservoir element
   2. the well pump
   3. a pipe connecting the well to its pump
   4. a junction
   5. a pipe connecting the pump to a junction
2. Split an existing pipe
3. Abandon an existing pipe (Deleted from source file so remove from model)
4. Add new discharge line

Preview of Source File

As mentioned, for this example the source file of modeling information is a geodataBase (GDB). This GDB contains four modeling elements (or hydraulic features).

1. Well
2. Tanks
3. Pump
4. Pipe

The modeling attributes in each of the features are shown below.

Updating the Model Using ModelBuilder

The steps below describe how to update the existing model. Some of the screens may look different depending on the source data you are using.

Open ModelBuilder

Choose ModelBuilder from the Tools menu, and ModelBuilder will open.

The initial window (see below) shows previously created database connections. For this example, we will assume that any databse connections previously used with our system have been deleted. If an applicable link were already present, it could be double clicked for more details, or the "Sync In" button could be used to update the model from the database.

For our example, click the New button shown to create a new database connection.

Specify the Data Source

After you intiate a new connection, the "Specify your Data Source" dialog appears. First, select the data source type (ArcGIS Geodatabase Features in our example), and then click Browse to identify the source file. 

Also on this screen, you can:

• Select which source data to use
• Select or deselect tables/ layers to be used
• Add an SQL query that can be applied to filter the table if required
• Preview the source data table

When the "Show Preview" box is checked, only the highlighted Table from the left will be displayed. Remember, if existing link is double clicked then the changes should be seen in the preview. If the changes are not there, start new model builder by clicking on "New" button on the first screen of ModelBuilder. In the image below, notice the number of pipes are different.

 Click Next.

Specify Spatial and Connectivity Options

 Depending upon the source file this screen may look different. In this step, first provide the unit of your Source Data. If not sure try with "ft". Second, "Create nodes if none found at pipe endpoint"; when this box is checked, ModelBuilder will create a pressure junction at any pipe endpoint that: a) doesn't have a connected node, and b) is not within the specified tolerance of an existing node. This field is only active when the Establish connectivity using spatial data box is checked. (This option is not available if the connection is bringing in only point type geometric data for example, Well or Wet-Well.)

 Note: Pipes will be connected to the closest node within the specified tolerance. The unit associated with the tolerance is dictated by the Specify the Coordinate Unit of your data source field.
Click Next.

Specify Element Create/Remove/Update Options

Depending upon the requirement the selection of options may vary. For this particular example following options are selected.

 Note: For detail information, press F1 and help file will be launched.
Click Next.

Specify Additional Options

This step is particularly important if the source file has Unique ID. In this workflow, there is a unique ID so GIS-ID has been selected. If there is no unique ID, Label will work the same. If Sync Out feature (updating the source file based on model updates) is planned to use then maintaining Unique ID is highly preferred. Help file explains each options in details, press F1 to launch help.

 Click Next.

Specify Field mappings for each Table/Feature Class

If the existing link had been double clicked then everything in this step should be good. If a new button had been clicked then all the necessary elements and the fields need to be mapped. Follow the "Specify Field mappings for each Table/Feature Class" from "Create A Model Using ModelBuilder" and come back to this step.
Click Next.

Create Model Now?

 Select "Yes" and click on "Finish".

Click Finish.

ModelBuilder Summary

Close the Summary after reviewing.

Click "Yes" in the next screen (below).

Finally the screen should look like below. Notice the existing features are turned off and new layers of the WaterGEMS are checked.

This concludes the model updating process using ModelBuilder.

See Also

Building A Model Using Model Builder

Updating Source File Using Model Builder

Setting Boolean (True/False) Fields using Modelbuilder

Product TechNotes and FAQs

Haestad Methods Product Tech Notes And FAQs 

WaterGEMS V8 Modeling FAQ 

External Links

Bentley Technical Support KnowledgeBase

Bentley LEARN Server

Water and Wastewater Forum