Editing Hydromanagement in Ancient India (section)

=== '''Lothal: The World's First Dockyard''' ===
In addition to walls, platforms, wells, drains, and paved bathing platforms, which are the typical water management system of Harappan cities, S.R. Rao identified a monumental brick-lined enclosure as the Dockyard. It is hypothesized that Lothal engineers studied the effects of tidal movements on brick-built structures, as the walls are composed of kiln-fired bricks. This knowledge also allowed them to select Lothal's location, as the Gulf of Khambhat has the greatest tidal amplitude and ships can pass through the river estuary's flow tides. A second inlet is provided on the opposite side of the main inlet, which is 12.8 meters (42 feet) in width. On the exterior wall faces, offsets were installed to counter the thrust of the water. At high tide, the water flow would have permitted ships to enter. Provision was made for the outflow of excess water via the outlet channel on the southern arm's uppermost point. Throughout their time, the city was subjected to numerous floods and storms. Docks and city perimeter walls were effectively maintained. The vociferous reconstruction of the city ensured the expansion and prosperity of the trade (Rao,1979)<sup>25</sup>.