By default, the log files in the wal directory that are backed up during a backup operation are not deleted after the backup job. If you want, you can delete these backed up log files after a backup by selecting the Delete archive logs check box.
From the navigation pane, go to Protect > Databases.
The Instances page appears.
Click an instance for which you want to delete archive logs after a backup operation.
The instance page appears.
On the Overview tab, click Edit.
The Edit PostgreSQL instance dialog box appears.
Select the Delete archive logs check box.