water system

The water suply system is based on a black plastic pipe,which is placed on the home-car's roof.

Details about the water pipe:
The diameter is 50 mm.
Length of the pipe is 50 meters.

The pipe is rolled 9 times and it is tied together,and placed on the home-car's roof.
The two ends of the pipe are connected to 16 mm pipes.
The lower one is supplying the water into the home-car water system(the shower and kitchen).
The upper end of the pipe is connected to a simple garden-sprayer.
The sprayer has it's own pressure meter.

And why is that?
To  keep the water pressure high, after using some water.We just have to press the sprayer handle and it works!
 So it does not need any electic pump!

How do we fill this amazing water tank?
Behind the shower wall ,there is a connection type T,on the supplying water pipe.A tap is connected to this T, and a garden pipe is connected to the tap(used to fill up the water tank).
The garden pipe is 10 meters long,so it can be connected to any tap anywhere.