the AMNH has a imax film on water.. and focus on the NY water system. NY water system, is basicly over 100 years old, an delivers all of the cities water needs (it was stressed by a drought, that ended in May) and it is primarly gravity fed. NYC water cleanliness and purity exceeds (i will admit at time low) US Federal standards... and is treated only with a low level of clorination.
but.. cities like NY are dependant on resourses far out of their reaches.. NY Water comes from reservours 100 miles away.. and while it has a good system, it has no viable alterantive.. with the lose or distructions of the water system, NY, would fade from sight, and other cities would take over its functions.. no one city would take over all of them i suspect, but still NY would sink into oblivion.. and as its resourses and value as a city failed, the harbor, in danger already of silting up, would. with out a port, or a good water supply, NY would lose 90% of its populations, and just be another small city half on the east coast, like new london or bridgeport..
likewise, energy in NYC is generated in Canada and Niagara falls.. (there are local generators, but we are dependent on the "grid", too..
i don't see how cities can outlive there usefulnes.. but what is defined as useful does change.. NY as i pointed out a few weeks ago, has a great natural Harbor, Bean, our resident oceanographer, said, oh, yeah... most people don't think of NY as port town. NY main focus has moved from ocean going shipping to financial management..
good cities have the ability to change.. Much is often made of Atlanta (GA) -- a city famous because it did not start out on a river or port.. but rather as a rail hub..
1000 years ago, overland transport was expensive and unreliable, and all cities were ports, for local and distant shipping.. some of those port silted up, and the cities disappeared.. others, developed lives for themselves aside from there original purpose.
150 years ago, Sag Harbor NY, and New Bedford MA were big cities.. Centers for whalers, and whale oil, whale ivory, and other imports.. today, both have remade themselves over as seaside resorts town. but both had hard times as they changed.. and some port cities never succeded in changing and langish.
other cities, redefine themselves to new needs..
London and Paris, port cities and capitals are no longer dependant on shipped goods or the crown. tourism, fashion, finacial markets contribute more to the cities health than shipping.. they have evolved.
