Other mistake: During the rescue at the top of the open drawbridge, in the shots of Engine 2 we can see the red, vinyl material with the company number imprinted on it, adhered to the front of the engine.
Other mistake: When Station 51 is dispatched to 'man trapped in vehicle', we can see the real Station 127's vehicle is still parked inside the apparatus bay, near the rear bay door.
Answer: It is standard practice to wet down driveways so that they stand out in a long shot.
stiiggy