When editing features with z-values, you can provide a default z-value that will be applied to any features inserted or updated through the feature service that do not include this information. For example, when editing with the SOAP and REST endpoints, the client may or may not include z-values. If a z-value is provided, the default z-value will be ignored. However, if a z-value is not included, this default z-value will be applied.
If you are editing a feature service in ArcMap with the local editing commands, the z-values can be set using the Sketch Properties tool 
on the Editor toolbar.
The following steps describe how to apply a default z-value to features that are edited through a feature service:
- Open ArcGIS Server Manager and log in. If you need help with this step, see Logging in to Manager.
- Click Services > Manage Services.
- In the Services module, click the name of your feature service. If you don't see your service in the list, it may be located within a folder in the Site (root) directory.
- In the Edit module, click Capabilities.
- Click the Feature Access option (the name, not the check box) under the Select and configure capabilities window. This displays the feature service properties.
- Check the Apply default to features with z-values check box.
- Enter a default z-value that will be applied to all inserted and edited features that have z-values in the feature service where the z-value is not provided by the client.
- Click the Save and Restart button to apply the changes to the service.