Gotta love those 'tie downs'.
I never got my head around the notion that an aircraft with a 500Kg empty weight and a wing able and allowed to lift 3000Kg (ie MAUW x 4.4g) is in any way inconvenienced from blowing away or flipping over by 25Kg of water under each wing - half the weight of a large pilot.
Seems no more than wishful thinking to me!