There was a great challenge to ensure uniform and undiminished water pressure in the fountains which was met by adopting an inventive method. The fountain pipes were not connected directly with the copper pipes feeding them as it would have resulted in a steady decrease in the volume and pressure of the water. As an alternative a copper pot was provided under each fountain pipe-which was thus connected with the water supply only through the pot water first fills the pot and then only rises at the same time in the fountains. The fountains are thus controlled by the pressure in the pots and not by pressure in the main pipe. As the pressure in the pots is consistently distributed all the time, it ensures an equal supply of water at the same rate in all the fountains. This was really a work of great foresight.
As for main supply of water, it was obtained through earthenware pipes.
One such main line of supply was discovered under the bed of the western
canal. The original intent of the builders of the Taj was probably to
present a synthetic composition. The irrigation work at the garden is a
great example of this. The garden is irrigated by the overflowing of
canals; exception being the outlets at the two extreme ends. The
fountains provide inlets to the north-south canal. The west-east canal
received its water through an interconnection with the north-south
canal. The quarters near the canals received an adequate supply of water
while the distant quarters got a smaller supply as the quarters near the
canals could be used for growing flower and other plants which would not
obstruct the general view. The distant quarters on the other hand ware
suitable only for tall trees. The Taj Mahal is perhaps the only monument
of the world with such great aesthetic considerations so detailed and
yet so influential.
Read about water works and water devices inside the Taj Mahal at Agra.