phpBB 3.1 extension which adds a new forum permission to send new topics to moderation. Once enabled you must set which forums, under the Misc tab of the forum, you want new topics to be on moderator queue on a per forum basis.
Clone (or download and move) the repository into the folder ext/rmcgirr83/newtopicsneedapproval:
cd phpBB3
git clone https://github.com/RMcGirr83/phpBB-3.1-New-Topics-Need-Approval.git ext/rmcgirr83/newtopicsneedapproval/
Go to admin panel -> tab customise -> Manage extensions -> enable New Topics Need Approval
Within the Admin panel visit the Forums tab and choose which forums, under the Misc tab of the forum, for new topics to put on moderation queue. The permission will be called Can start new topics without approval and all forums are set to Yes upon installation. Ensure after installing this extension you purge the cache in the ACP.