Like Pergau, it will also provide some electricity, though not, of course, as much as forecast. But the main purposes of the Turkish government's project are quite different. The first is to hold Syria and Iraq to ransom by controlling the flow of the river Tigris. The second is to assist its ethnic cleansing programme. The Kurds regard the city as their cultural heartland.
Turkey sees it as an emblem of resistance.
When Hasankeyf and surrounding settlements are drowned by the dam, some 20,000 Kurds will be forced from their homes and moved into model villages in which they can be monitored and controlled. Our government, which went to war in the spring to stop ethnic cleansing, is, in the winter, underwriting it. It is not hard to see why. British companies see the country's defence sector as a massive potential market. The Labour government's involvement in the Ilisu dam may be the biggest corruption scandal in western Europe, but you could be forgiven for having missed it.