We have a storage trailer too, currently used for greeting cards, Sterilite, patio furniture and pet food. Despite the two raccoon-sized holes where the trailer doesn't meet the dock. Oh and sometimes we put shippers in there and don't tell POG team about them. Then again, half the time they never take down the ones that are clearly visible in the steel so it probably wouldn't change a thing.
Paper and water go in various places in the steel on receiving side, stuff for the sweep goes outside if it's a bale or pallet and wherever the hell you can find room inside for the rest.
To be honest, I hate our whole setup. There's bales that have been sitting outside for weeks because I can't get them back in through the receiving door and would have to take the Crown all the way around to a bay to get them inside. Wet pallets are gross. I'd give up something precious to get that trailer out so I could have two docks for deliveries. Then again, the storage dock's plate doesn't work because it was cannibalized for parts for my one (barely) working dock's plate some time ago.
But that is for another time.