When Tallis and the girl jump out of the window, and Tallis blows a hole in the street so they can fall into the sewer. There is a shot from under the water that shows them hitting the water and then swimming back up to the surface, but the next shot shows them stand up and the water level in the sewer is only knee deep.
Towards the end of the movie, three red drones are hunting Tallis in a sewer. The water level is only knee deep. Tallis dives under the water's surface and the shot shows him swimming in water that is waist deep to the drones. The next shot shows Tallis coming up out of the water behind the last drone and killing it. However the water level is only knee deep. Tallis then ducks back under the water and we see a shot of him swimming around again in water that is at least waist deep.