---
title: "Use the z-mod vertices tool"
slug: "how-to-use-the-z-mod-vertices-tool"
description: "Learn to use the zmod vertices tool"
updated: 2024-08-07T15:15:26Z
published: 2024-08-07T15:15:26Z
canonical: "help.floodmodeller.com/how-to-use-the-z-mod-vertices-tool"
stale: true
---

> ## Documentation Index
> Fetch the complete documentation index at: https://help.floodmodeller.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Use the z-mod vertices tool

Modifying the elevation of an area within your model can be used for specifying elevations for proposed defences, filling holes/areas of missing data in your underlying DTM, and much more.

Once you have defined the location for the modification, you can use the **z-mod vertices tool** to fill the vertices with the new elevation data.

![](https://cdn.document360.io/5074bc26-a9ef-4bf4-b1de-a5c6ce628aca/Images/Documentation/usezmodtool.PNG)

### Steps

1. Ensure the z-mod area (polygon, line or point shapefile) is selected within the **Layers** panel. On the **2D Build** tab, within the **Z mod** section, click **Z mod vertices** to open the tool in a new window.
2. Your selected shapefile is provided in the **Input Shapefile** field. If required, use the drop-down to browse to other shapefiles loaded in the **Layers** panel, or the button on the right to browse to other (unloaded) shapefiles.
3. Drag the DTM (or other grid containing your elevation data) into the field provided. This data will fill the vertices of your shapefile area. You can add multiple files here if required; values from lower layers in the list will take precedence.

Tip:

Uncheck the box **Update heights from DEMs** to not select any files. In this case, the vertices will filled with -9999 data (to be [edited manually](/v1/docs/how-to-edit-z-mod-attributes)).
4. Click **Process** and text to the left of this button will appear to confirm when the process is complete. Close the tool and a new shapefile will now be added in the **Layers** panel. Contained in this shapefile are the vertices of your initial shapefile, filled with the data from the grid,

Note:

By default, the new shapefile has the name of the initial shapefile, proceeded by -zpoints, e.g. MyInitialShapefile-zpoints.