Continuity mistake: When Chet is being timed while putting on his gear, Squad 51 is parked much further up than the engine, providing more room in the apparatus bay behind the squad to run the drill. Then when Station 51 is dispatched to the explosion, the squad's parked normally. Additionally, we see the front bay door is closed, but that's impossible considering how far up Squad 51 was parked during the drill.
Continuity mistake: When Roy and John are in the ER's staff lounge discussing Donaldson, Roy's button, second from the top, is buttoned up in the wide shots, but is unbuttoned in his closeups during the conversation.
Continuity mistake: When Roy and Johnny are with the man in full arrest on the tower at the refinery, Johnny hooks up the Datascope with the wire, but in all the overhead shots there is no wire at the back of the Datascope monitor.
Continuity mistake: At the refinery fire, when Johnny and Roy are on the tower with the collapsed worker, Roy throws the line down to Truck 127's Snorkel for their gear, and as Roy pulls it up, the gear is tied up quite differently depending on the angle of the shot.
Continuity mistake: When Kent (Bobby Sherman) is ready to leave Station 51, the guys are about to sit down to dinner and the table is full of food, plates, cups, utensils, etc, but when the tones drop for the refinery fire and everyone rushes into the apparatus bay, the table is seen behind them and it's bare. Also, the order in which the guys run out of the kitchen is completely different, depending on the angle of the shot.
Answer: It is standard practice to wet down driveways so that they stand out in a long shot.
stiiggy