THE RAMAT RAHEL WATER SYSTEM is covered today in a Reuters article that has some new details:

Ancient biblical waterworks found in Israel
Wed Aug 23, 2006 2:43am ET147

By Corinne Heller

RAMAT RACHEL, Israel (Reuters) - Archaeologists in Israel have unearthed an ancient water system which was modified by the conquering Persians to turn the desert into a paradise.

[...]

The infrastructure of the palace was remodeled throughout the centuries to fit the needs of the Babylonians, Persians, Romans and Hasmoneans who ruled the Holy Land, said Lipschits, who heads the dig with an academic from Germany's University of Heidelberg.

But it was the Persians, who took control of the region around 539 BC from the Babylonians, who renovated the water system and turned it into a thing of beauty.

[Oded] Lipschits said they added small waterfalls to try to turn a desert into a paradise.

[...]