Drainage is a multiplayer map featured in Call of Duty: Modern Warfare designed exclusively for the Gunfight mode that was released on March 31st, 2021 update and became available in Private Match. On April 6th, the map was removed from the game. On April 12th, 2021, Infinity Ward tweeted out that the map alongside Al-Raab Airbase were temporarily removed as they are not ready and needed minor changes.  The map was re-added two months later on June 29th.  
This is a fairly symmetrical location which takes somewhere in Urzikstan. The Kushaak Construction company and Rothwynn were supposed to have been renovating the drainage system underneath the bridge, as evidenced by open pipes, yellow worker hats, cranes and some boards and plastic sheets with their insignia respectively. This place has however been taken over by Al-Qatala, as seen with banners set up across the map, stopping the renovation.
- Similar to Al-Raab Airbase, one can find paper boards with UNSA forms on it which haven't been filled. This is a callback to Call of Duty: Infinite Warfare, where the UNSA is one of the factions in it.
- The map is an altered version of Euphrates Bridge.
- It is possible to find a Teddy Bear next to an electric guitar in one of the opened pipes outside the map.