Few creations of big technology capture the imagination like giant dams.Perhaps it is humankind’s long suffering at the mercy of flood and drought that makes the ideal of forcing the waters to do our bidding so fascinating.But to be fascinated is also, sometimes, to be blind.Several giant dam projects threaten to do more harm than good.
　　The lesson from dams is that big is not always beautiful.It doesn’t help that building a big, powerful dam has become a symbol of achievement for nations and people striving to assert themselves.Egypt’s leadership in the Arab world was cemented by the Aswan High Dam.Turkey’s bid for First World status includes the giant Ataturk Dam.